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Adames, Juan M. "Characterization of Polymeric Binders for Metal Injection Molding (MIM) Process." University of Akron / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=akron1194319407.
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Hemrick, James Gordan. "Release characteristics of 17-4PH stainless steel metal injection molding in SLA epoxy molds." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/19646.
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Kong, Xiangji. "Development and characterization of polymer- metallic powder feedstocks for micro-injection molding." Phd thesis, Université de Franche-Comté, 2011. http://tel.archives-ouvertes.fr/tel-00844736.
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Micro-Powder Injection Moulding (Micro-PIM) technology is one of the key technologies that permit to fit with the increasing demands for smaller parts associated to miniaturization and functionalization in different application fields. The thesis focuses first on the elaboration and characterization of polymer-powder mixtures based on 316L stainless steel powders, and then on the identification of physical and material parameters related to the sintering stage and to the numerical simulations of the sintering process. Mixtures formulation with new binder systems based on different polymeric components have been developed for 316L stainless steel powders (5 µm and 16 µm). The characterization of the resulting mixtures for each group is carried out using mixing torque tests and viscosity tests. The mixture associated to the formulation comprising polypropylene + paraffin wax + stearic acid is well adapted for both powders and has been retained in the subsequent tests, due to the low value of the mixing torque and shear viscosity. The critical powder volume loading with 316L stainless steel powder (5 µm) according to the retained formulation has been established to 68% using four different methods. Micro mono-material injection (with 316L stainless steel mélange) and bi-material injection (with 316L stainless steel mélange and Cu mélange) are properly investigated. Homogeneity tests are observed for mixtures before and after injection. A physical model well suited for sintering stage is proposed for the simulation of sintering stage. The identification of physical parameters associated to proposed model are defined from the sintering stages in considering 316L stainless steel (5 µm)mixtures with various powder volume loadings (62%, 64% and 66%). Beam-bending tests and free sintering tests and thermo-Mechanical-Analyses (TMA) have also investigated. Three sintering stages corresponding to heating rates at 5 °C/min, 10 °C/min and 15 °C/min are used during both beam-bending tests and free sintering tests. On basis of the results obtained from dilatometry measurements, the shear viscosity module G, the bulk viscosity module K and the sintering stress σs are identified using Matlab® software. Afterwards, the sintering model is implemented in the Abaqus® finite element code, and appropriate finite elements have been used for the support and micro-specimens, respectively. The physical material parameters resulting from the identification experiments are used to establish the proper 316L stainless steel mixture, in combination with G, K and σs parameters. Finally, the sintering stages up to 1200 °C with three heating rates (5 °C/min, 10 °C/min and 15 °C/min) are also simulated corresponding to the four micro-specimen types (powder volume loading of 62%, 64% and 66%). The simulated shrinkages and relative densities of the sintered micro-specimens are compared to the experimental results indicating a proper agreement
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Bombera, Mojmír. "Návrh technologie výroby plastového emblému automobilu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-230862.
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The project elaborated in scope of engineering studies branch 2307. The project is submitting design of production technology of car emblem. Different manufacturing technologies have been compared based on study of technical literature. Most suitable technologies have been chosen such as pressure die casting, especially aluminum alloys and plastic injection molding. Plastic part is metal plated afterwards in order to get desired metal look. Part of this project is injection molding tool design inclusive technical, technological and economic analysis.
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Mariot, Paulo. "Ferro puro moldado por injeção para aplicação em Stents biodegradáveis." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/150294.
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Na presente pesquisa, produziu-se amostras de ferro puro poroso como biomaterial degradável visando a aplicação em stents, pelo processo de moldagem por injeção de pós metálicos (MPI). Os efeitos da fração volumétrica de ferro puro na mistura de injeção e da temperatura de sinterização na porosidade, microestrutura, propriedades mecânicas, propriedades de superfície, de degradação in vitro e de biocompatibilidade, foram investigados. Os resultados obtidos foram comparados com o ferro puro fabricado por fusão e com o aço inoxidável AISI 316-L. Encontrou-se que o grau de porosidade remanescente nas amostras sinterizadas foi o principal fator influenciando as propriedades mecânicas e de superfície, influenciando indiretamente os demais resultados. O ferro puro produzido por MPI exibiu valores de limite de escoamento entre 59 e 114 MPa e limite de resistência máximo de 210 MPa, com alongamento entre 10 e 50 %. A alta ductilidade é uma propriedade especialmente requerida em materiais para potencial aplicação em stents. Suas taxas de degradação em solução de Hank foram superiores às do ferro puro fabricado por fusão. O material fabricado com mistura de injeção contendo fração de ferro de 66 % (acima da fração crítica) mostrou o maior alongamento e boa taxa de degradação, um resultado interessante, pois segundo a literatura, valores acima da fração volumétrica crítica não são amplamente explorados. Os testes de biocompatibilidade mostraram excelente hemocompatibilidade do ferro puro fabricado por MPI com as células do sangue. Todas as condições testadas mostraram um nível de citotoxicidade abaixo do recomendado pela norma vigente, mas este dependendo da concentração de íons de ferro empregada e do grau de porosidade. Entre todas as condições de ensaio investigadas, as amostras contendo fração volumétrica de ferro de 62 % inicialmente na mistura de injeção e sinterizadas a 1120 oC, apresentaram a melhor combinação de propriedades para aplicação em stents. Concluiu-se que a MPI é um método tecnicamente viável como rota de produção de tubos de parede fina precursores para fabricação de stents biodegradáveis.In the present research, an attempt was made to produce porous pure iron, as a metallic degradable biomaterial potentially for stent application, via the MIM route. The effects of iron powder loading and sintering temperature on the porosity, microstructure, mechanical properties, surface properties and in vitro degradation behavior of MIM iron were investigated. The results obtained were compared to those of cast iron. It was found that the amount of porosity remained in the as-sintered specimens had a major effect on their surface and mechanical properties. The MIM pure iron showed yield strength values between 59 and 114 MPa and maximum tensile strength of 210 MPa, with elongation values between 10 and 50 %. A high ductility is a specially required property of stent materials. Its degradation rates in Hank’s solution were superior to the degradation rate of cast iron. The material made from the feedstock containing 66 % of iron powder, above the critical powder loading, showed the highest elongation and a good in vitro degradation rate. This result is interesting, once according to the literature, powder loadings above the critical value are not well explored. The biocompatibility tests showed excellent hemocompatibility of MIM pure iron with blood cells. All conditions tested showed toxicity level below the values determined by current standards, but depending of Fe ions concentration and porosity level. Between all the conditions tested in the present investigation, the 62 % powder loading sample, sintered at 1120 oC, showed the best combination of properties for stent application. In conclusion, MIM is a promising method to be developed as a new route to produce thin-wall tubes for biodegradable stents.
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Afraz, Syed Ali. "Mechanical, Microstructural and Corrosion performance for MIM materials based on coarse (-45µm) powders of ferritic stainless steel." Thesis, KTH, Materialvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-127680.
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The purpose of this research is to investigate the mechanical, microstructural and corrosion performance of the ferritic stainless steel coarse powders, used in Metal Injection Molding (MIM) process. Three coarser powders made by Höganäs AB, were examined along with a commercially available fine MIM powder and samples from sheet metal. The studied powders were individually mixed with binders and then injection molded in the shape of dog bone shaped tensile bars. These green samples were then debinded and sintered to examine under different characterization methods. The methods used for examining the samples were tensile test, hardness test, metallography, SEM, chemical analysis, and salt spray test. After a comparative study of these different materials, it turns out that the chemical composition and the process parameters have more effect on materials properties compared to only particle size distribution in studied materials. After this study, 434 coarse powder was preferred upon the PolyMIM 430 fine powder, because of its lower price and same performance as that of PolyMIM 430.
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Tavares, André Carvalho. "Avaliação de misturas injetáveis aplicadas à fabricação de micro componente para pinças de biópsias por moldagem de pós por injeção." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/116649.
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A moldagem de pós por injeção (MPI) foi empregada neste trabalho para a fabricação de micro componentes de uma pinça de biópsia, através do desenvolvimento de misturas injetáveis. Utilizou-se a liga de aço inoxidável AISI 316L, liga reconhecidamente biocompatível, para obtenção dos micro componentes. Determinando a quantidade de 39% em volume para fração orgânica das quatro formulações de misturas injetáveis produzidas neste trabalho. Os polímeros estruturais empregados foram o PP, o PEBDL, o PEAD e o PMMA. Como material auxiliar de fluxo foi utilizada a parafina e para agente surfactante, o ácido esteárico. O desenvolvimento do sistema de extração química do polímero auxiliar de fluxo com solvente e posterior extração térmica do ligante em forno convencional e em um reator a plasma foram testados, ainda se empregou estes para testes em sinterização a temperaturas 1200°C, 1250°C e 1300°C. A extração química foi realizada com hexano atingindo 2,41% em massa de material extraído das amostras, após seis horas em um sistema aquecido entre 60°C e 70°C e uma atmosfera de vácuo. As amostras foram testadas química, física, mecânica e eletroquimicamente. Obteve-se os melhores resultados em termos de densificação de 7,05 g/cm³ para as amostras extraídas a plasma e sinterizadas a 1300 °C à vácuo em forno tubular. Isso significa uma densificação de 88,96% comparada a densidade do material comercial cuja a densidade é 7,93 g/cm³. As microdurezas encontradas nas amostras sinterizadas a 1300 °C em um forno convencional obtiveram valores de 208HV se mostrando maiores do que os 165HV obtido de um material maciço fabricado pelo extrusão e comercialmente vendido. Encontrou-se a dureza de 55HRB nas amostras processadas a 1300 °C, devido a presença de poros em componentes sinterizados. Nos componentes maciços foram medidos a dureza de 88HRB que foi maior que os resultados das amostras sinterizadas. As análises metalográficas mostraram um tamanho de grão variando entre, 30 e 50μm, se comparado ao tamanho de partícula médio do D90 de foi de 8,59 μm, se estima que este aumento foi entorno de três vezes e meia. Os testes químicos revelaram que a extração térmica em reatores a plasma melhoram significativamente os níveis de C, N, H e S quando comparados ao processo de extração térmica em forno convencional. A redução dos níveis de carbono residual, resultaram em diminuição do carboneto de cromo nas amostras, provocando uma menor corrosão. As amostras sinterizadas a 1200 °C a plasma apresentaram os melhores resultados de corrosão.The powders injection molding (PIM) was used in this research, with objective to manufacture micro component, for application in biopsy forceps being developed injectable mixtures . It was used the powder stainless steel AISI 316L alloy, material biocompatible, to obtain the micro components. Through tests was determining the amount optimal volume in 39 % for the organic fraction of the four formulations of injectable mixtures produced in this research. The structural polymers used were PP , LLDPE , HDPE and PMMA . The paraffin was used as auxiliary material flow, the surfactant agent employed that was stearic acid . The development of chemical debiding and the thermal extraction for binder system, was used the conventional furnace and in a plasma reactor were tested also be employed for these tests sintering temperature 1200 ° C , 1250 °C and 1300 °C. Chemical extraction was performed with hexane achieving 2.41 % by extracted mass of sample material, after six hours in a heated system between 60 °C and 70 °C and a vacuum atmosphere. The samples were tested analysis by chemical , physical , mechanical and electrochemical.If it obtained the best results in terms of densification of 7.05g/cm ³ for plasma samples extracted and sintering at 1300 °C in vacuum tube furnace . This means densification of 88.96 % compared to the density of commercial material whose density is 7.93 g/cm ³ . The microhardness found in the samples sintered at 1300°C in a conventional furnace obtained 208HV microhardness showing larger than the commercial 165HV. Found that the HRB hardness of 55 in the samples processed at 1300 °C, due to the presence of pores in sintered parts. In the extruded components were measured hardness of 88HRB which was higher than the results of the sintered samples. The metallographic analysis showing a grain size ranging between 30 and 50μm , compared to the average particle size D90 was 8,59 microns is estimated that this increase was around three and half times . The chemical tests revealed that the thermal plasma extraction reactor significantly improve the levels of C, N , H and S compared to the process heat extraction in a conventional furnace . The residual carbon levels significantly improved, which helps to avoid the formation of chromium carbides , which aumnetou corrosion resistance . The best results in terms of corrosion were found for the samples sintered at 1200 ° C the plasma.
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Tourneroche, Paul. "Développement de mélanges chargés en poudres d'aluminure de titane pour moulage par injection et applications aéronautiques." Thesis, Besançon, 2016. http://www.theses.fr/2016BESA2057.
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La réduction de l’impact des activités humaines sur l’environnement est au sujet de nombreux programmes de recherche. Ainsi, dans le domaine du transport aérien a été créé le projet Clean-Sky, regroupant les thèmes de recherche associés. La thèse, partie de ce dernier, a pour objectif de réduire l’impact environnemental de la production de composants en alliages avancés à base de Titane. La production actuelle ayant une empreinte écologique non négligeable, un procédé de fabrication alternatif est étudié, il s’agit du moulage par injection de poudres métalliques. La première partie de cette consiste donc en la recherche d’une formulation de mélange optimale parmi les solutions classiques et innovantes. Elles sont triées en fonction de leurs aptitudes, déterminées par caractérisations physico-chimiques, à assurer le bon déroulement de chaque étape du procédé. Un nombre réduit de solution étant ainsi dégagé, il s’agit de passer aux étapes d’injection, de déliantage et de frittage. Plusieurs géométries de pièces sont testées dans chacun de ces cas, afin de valider l’adaptation aux différentes contraintes imposées. Lors de ces trois phases, des analyses physico-chimiques complètes permettent de mettre en avant la ou les formulations les plus aptes à permettre la production de ces composants. Une fois la solution fixée, chaque étape du procédé est optimisées, afin de faciliter le transfert industriel et d’assurer la rentabilité du nouveau processus de fabrication. Ces travaux de doctorat ont permis de mettre en avant deux formulations, répondant aux critères définis en début de thèse. Les étapes de mélange, injection, déliantage et frittage ont été optimisées et le transfert industriel est possibleReducing the ecological footprint of human activities is, today, the aim of most of the research programs. In Europe, the « Clean Sky » project funds research activities to make air transport « greener ». This PhD, being part of it, is about improving production of Titanium Aluminide based components. Nowadays production having a strong environmental impact, an alternative way has been investigated: metal injection molding. The first step of this work was focused on a bibliographic study, to select relevant, common and innovative mixtures to be used in the process. Throughout the process, these mixtures have been tested, physically and chemically analyzed, to get data about the optimal mixture. Several components geometries have been tested, during injection, debinding, and sintering steps. Once the mixture(s) chosen, process’ parameters have been optimized to make industrial transfer easier, and lower its overall cost. The developments achieved during this PhD led to two qualified mixtures, and optimized mixing, molding, debinding and sintering steps
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Rohne, Clemens, Michael Schreiter, Jens Sumpf, Klaus Nendel, and Lothar Kroll. "Hybrid Conveyor Chains – Calculation, Design and Manufacturing." Universitätsbibliothek Chemnitz, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-231781.
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The following paper will illustrate the development of a multiflex chain in hybrid construction. The aim of this novel chain variant is to improve the stiffness and strength in comparison to conventional plastic slide chains. A two part multiflex chain with a chain pitch of 33.5 mm and a structural width of 83 mm was used as the basis for the development of the hybrid multiflex chain. The hybrid multiflex chain is supposed to be integrated in already existing layouts of chain conveyors. The load bearing structure of the single chain links is manufactured in the metal die cast procedure while taking the constructive, production related, and operational aspects into consideration and subsequently covered in the injection molding process with plastics commonly used for multiflex chains. The evaluation of the improved stiffness and strength takes place in the course of extensive test seriesIn der folgenden Abhandlung wird die Entwicklung einer Multiflex-Kette in Hybridbauweise erläutert. Mit dieser neuartigen Kettenvariante soll eine Steifigkeits- und Festigkeitssteigerung gegenüber den konventionellen Kunststoffgleitketten erzielt werden. Als Ausgangsbasis für die Entwicklung der hybriden Förderkette dient eine zweiteilig ausgeführte Multiflex-Kette mit der Teilung von 33,5 mm und einer Baubreite von 83 mm. Die hybride Förderkette soll in bestehende Layouts von Kettenförderern integriert werden können. Unter Beachtung konstruktiver, fertigungstechnischer und betrieblicher Aspekte wird die lasttragende Struktur der einzelnen Kettenglieder im Metalldruckgussprozess gefertigt und anschließend mit einem, für Multiflex-Ketten üblichen Kunststoff im Spritzgießprozess ummantelt. Die Evaluierung der Steifigkeits- bzw. Festigkeitssteigerung erfolgt im Rahmen umfangreicher Versuchsreihen
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Oliveira, Alex Sandro Matos de. "Fabricação de pinças de biópsias a partir do processo de micromoldagem de pós metálicos por injeção com aplicação à endoscopia flexível." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/108505.
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Neste trabalho foi desenvolvido o projeto e fabricação de quatro componentes de uma pinça de biópsia (concha, garfo, oito e haste), através da micromoldagem de pós metálicos por injeção. A matéria prima utilizada neste trabalho é conhecida comercialmente como CATAMOLD® 316L A. Corpos de prova foram obtidos através da injeção em uma injetora de baixa pressão para determinação da quantidade de pó de aço inoxidável 316L e sistema aglutinante contida na matéria prima. Ensaios de injetabilidade foram realizados para análise do comportamento da matéria prima no processo de injeção. Foram avaliados os parâmetros de injeção (temperatura de injeção, temperatura do molde e velocidade de injeção) e as variáveis de saída (pressão de injeção, massa, segregação entre pó e sistema aglutinante e densidade). A influência dos parâmetros de injeção sobre as variáveis de injeção foi analisada através do delineamento estatístico via Redes Neurais Artificiais (RNA), com a utilização do programa Statgraphics® Centurion XV. Os corpos de prova obtidos na injetora de baixa pressão apresentaram alta quantidade de pó de aço inoxidável (92,2% em massa). Devido a esta alta concentração de pó, os ensaios de injetabilidade realizados na injetora de alta pressão apresentaram valores elevados para as pressões de injeção, variando de 1641 a 2115 bars para que houvesse o preenchimento total das cavidades. O molde microusinado para os componentes da pinça se mostrou eficiente na fabricação dos componentes, porém apresentou dificuldades na extração das peças. Mesmo com a obtenção de todos os componentes a montagem da pinça não foi realizada, visto que as furações de montagem foram retiradas no projeto, consequentemente não foram usinados. Depois de microinjetados, os componentes da pinça foram sinterizados e apresentaram variação dimensional de 0,01 a 0,29 mm em relação às dimensões de projeto e variação na contração de 7,05 a 13,33%, diferentes dos 14,30% citados no catálogo do CATAMOLD® 316L A.In this work the design and manufacture of four components of the biopsy forceps (ladle, fork, eight and rod), by metal powder injection molding was developed. The feedstock used in this work is known commercially as CATAMOLD® 316L A. Specimens were obtained by injection into a low-pressure injection molding machine for determining the amount of 316L stainless steel powder and binder system contained in the feedstock. Mouldability tests were performed to analyze the behavior of the feedstock in the injection process. The injection parameters (injection temperature, mold temperature and injection speed) and output variables (injection pressure, mass segregation between powder and binder system and density) were evaluated. The influence of injection parameters on the variables of injection was analyzed using the statistical design via Artificial Neural Networks (ANN), using the software Statgraphics® Centurion XV. The specimens obtained at low pressure injection showed high amount of stainless steel powder (92.2 wt%). Due to this high concentration of power, mouldability tests were performed in high-pressure injection showed high values for injection pressures ranging from 1641 to 2115 bars so that there was the complete filling of cavities. The micromachined mold for the components of the forceps proved efficient in the manufacture of components, but presented difficulties in the extraction of parts. Even with the obtaining of the all the components the biopsy forceps was not assembled, since the mounting holes were taken in the project, and therefore were not machined. After injected , the components of the forceps were sintered and showed dimensional variation from 0.01 to 0.29 mm in relation to project dimensions and variation in contraction from 7.05 to 13.33% , different from those 14.30% cited in the catalog of CATAMOLD® 316L A
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Luna, Wilberth Harold Deza. "Desenvolvimento de ímãs de Nd-Fe-B pelo processo MPI- aplicados em máquinas elétricas (motores)." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2012. http://hdl.handle.net/10183/109162.
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O processo tradicional de fabricação de ímãs de terras raras – TR – é a metalurgia do pó convencional. Este processo inclui etapas de preparação da liga, moagem, compactação sob campo e sinterização. Atualmente, ímãs obtidos pelo processo de injeção tem como resultado os ímãs conhecidos como bonded, que são compósitos de resina e ligas magnéticas. O processo de obtenção proposto neste trabalho é a moldagem de pós por injeção – MPI, o que implica novos desafios uma vez que ligas de terras raras são altamente reativas. A obtenção de ímãs de Nd-Fe-B por esse processo fornece a oportunidade de diversificar ainda mais os setores, potencialmente lucrativos, que trabalham com materiais magnéticos. As dificuldades desse processo foram encontradas em cada etapa, desde a mistura da liga com os polímeros à eliminação destes polímeros depois de as peças serem injetadas, essa etapa se tornou crítica dado que está diretamente relacionada às propriedades finais do material. Assim, propuseram-se novos ciclos de extração dos polímeros com solventes orgânicos e degradação térmica. Além disso, modelou-se ferramental para o processo de injeção, uma vez que o material deve ser orientado magneticamente durante a injeção. Finalmente usou-se o MAXWELL 14® (software para análises por elementos finitos para resolução em 3D) para incluir propriedades no banco de dados do software e assim predizer o comportamento do material quando aplicado nas máquinas elétricas de núcleos com de formato complexo.The typical magnets production process of Rare Earths – RE is the conventional powder metallurgy. This process includes preparation stages of alloys, grind, pressing under field and sintering. Nowadays, magnet obtained by the injection process has as result the magnets known as bonded, that is a resin composite and magnetic alloys. The proposed process to obtainment, in this work, is the Metal Injection Molding- MIM, what involve new challenges once alloys of RE are highly reactive. The magnets obtainment of ND-Fe-B for this process supplies even opportunity of diversifying the sectors, potentially lucrative, that work with magnetic materials. The difficulties of this process were found in each stage, since the alloy mixture with the polymers to the elimination of these polymers after the pieces are injected, this stage became criticizes given it is directly related to final properties of the material. This way if it propose to polymers extraction new cycles with organic solvents and thermal degradation. Moreover, it modeled die for the injection process, once the material should be guided magnetically during the injection. It finally used MAXWELL 14 ® (Software for analyses by finite elements for resolution in 3D) to include properties on the bench of data of the software and thus predict the material behavior when applied in cores of electrical machines with complex shape.
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Freitas, Willian Januário de. "Influência da atmosfera de sinterização na dureza e resistência à corrosão do aço inoxidável 17-4 PH conformado a partir do processo de moldagem de pós por injeção." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/18/18158/tde-11062015-171314/.
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O processo de moldagem de pós injeção é utilizado para a fabricação de peças de geometrias complexas e com alto volume de produção. Em aplicações ortodônticas e médicas, nas quais são requeridas elevadas durezas e resistências à corrosão, o aço inoxidável 17-4 PH é utilizado aplicando-se aquela técnica de conformação. A atmosfera de sinterização é responsável pelo controle das reações químicas que ocorrem durante a densificação do material e são fundamentais para a qualidade final do produto. O objetivo deste trabalho foi avaliar a influência da atmosfera de sinterização na dureza e resistência à corrosão deste tipo de aço. A remoção dos ligantes primários foi realizada por meio de extração química utilizando-se um solvente com menor impacto ambiental, que se mostrou adequado a tal fim. A extração térmica posterior dos ligantes foi realizada pelo aquecimento nas temperaturas de 250°C e 450°C sendo, posteriormente, a temperatura elevada a 900°C, para o início da sinterização. Utilizou-se atmosferas de Nitrogênio, Vácuo e Hidrogênio, com temperaturas de sinterização de 1250°C e 1330°, com tempos de patamares de 30 e 60 minutos. Verificou-se que as densidades atingidas nas atmosferas de Hidrogênio e Vácuo são semelhantes e se adequaram às especificações requeridas pela norma, enquanto a atmosfera de Nitrogênio resultou em características inferiores. As durezas e as resistências à corrosão obtidas com o uso das atmosferas de Hidrogênio e Vácuo foram também superiores as das amostras sinterizadas em atmosfera de Nitrogênio.The powder injection molding process is used to manufacture parts with complex shapes, with high production demand. In orthodontic and medical applications, in which high hardness and corrosion resistance are required, 17-4 PH stainless steel is used by applying this forming technique. The sintering atmosphere is responsible for controlling the chemical reactions that occur during material densification and is critical to the ultimate product quality. This research study aims at evaluating the influence of the sintering atmosphere on the hardness and corrosion resistance of this type of steel. The removal of the primary binder was carried out by chemical extraction applying a solvent with less environmental impact, which has proved to be suitable for this purpose. The subsequent binder thermal extraction was held by heating at temperatures of 250°C and 450°C and, therefore, at temperature of 900°C, to initiate sintering. Nitrogen, vacuum and hydrogen atmospheres were used with sintering temperatures at 1250°C and 1330°, with 30 and 60 minute-step time. It was verified that the densities achieved in hydrogen and vacuum atmospheres are similar and suitable by the regulations, whereas the nitrogen atmosphere resulted in lower performance. The hardness and corrosion resistance obtained with the use of hydrogen and vacuum atmospheres were also higher than those obtained for samples sintered in the nitrogen atmosphere.
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Härtig, Thomas. "Stoffübertragung beim Spritzgießen." Doctoral thesis, Universitätsbibliothek Chemnitz, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-108290.
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Das Fügen mehrerer Komponenten während des Spritzgießprozesses wird bei vielen Spritzgießsonderverfahren angewandt. Diese Arbeit beschäftigt sich mit der Verbundbildung zwischen einem kalten Einlegeteil und der einströmenden Kunststoffschmelze beim Spritzgießen, im Folgenden Stoffübertragung genannt. Ein Großteil der Untersuchungen findet an Zweikomponenten-Zugstäben statt, wobei erste und zweite Komponente aus dem gleichen Thermoplast gefertigt werden. Mögliche Einflussfaktoren auf die Verbundfestigkeit werden zunächst im Theorieteil vorgestellt und diskutiert. Eine Auswahl relevanter Prozess- und Materialparameter wird dann in praktischen Versuchen detailliert analysiert. Es wird nach korrelierenden Tendenzen sowohl zwischen unterschiedlichen Verfahren als auch zwischen verschiedenen Kunststoffen gesucht. Mittels statistischer Versuchsplanung werden die Spritzgießparameterkombinationen nach Größe des Einflusses auf die Verbundfestigkeit sortiert. Dies trägt zum Verständnis der bei der Stoffübertragung ablaufenden Grundmechanismen bei. Weiterhin werden die Einflüsse der Prozessparameter auf das neue Verfahren der In-Mold Oberflächenmodifizierung, bei dem ein funktionaler Modifikator während des Spritzgießprozesses übertragen wird, mit den Ergebnissen der Zweikomponenten-Verbundfestigkeit verglichen. Abschließend wird auf die Besonderheiten bei der selektiven Stoffübertragung eingegangen und das neue Verfahren des In-Mold Printing vorgestelltThe joining of two components by the process of injection molding is state of the art, although adhesion phenomena are not fully understood yet. The formation of bonds between a cold material, which was inserted or applied onto the surface of the cavity before injection molding, and an injected polymer melt is studied in this work. Providing sufficient bond strength, the material is transferred from the surface of the mold to the injection molded part. Possibly influencing factors on the bond strength are first identified, theoretically discussed, later in experiments varied and finally analyzed. Thereby correlating tendencies between different polymers and different in-mold technologies are observed. The relevant material and processing parameters are put in order by their influence on the bond strength using design of experiments. This helps to understand the mechanisms of the formation of bonds. The majority of the experiments is concerned with two component injection molding by measuring the bond strength of two component tensile bars, produced under varying processing conditions. In each case, first and second components are made of the same thermoplastic polymer. The thermal energy of the melt can be used also to initiate chemical reactions. This permits bonding of a thin layer of a functional polymer, which is applied onto the surface of the mold before injecting the melt, to the surface of the molded part. In this way, process-integrated surface modification during injection molding becomes possible. In a further attempt, patterns of paint are printed onto the surface of the mold by pad printing. During injection molding the paint is transferred completely to the surface of the polymeric part. Using this new technology of In-Mold Printing, fully finished surface decorated parts can be produced by injection molding
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Huang, Meng Cheng, and 黃孟楨. "Metal injection molding industry competitive strategy." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/98892866551933973850.
Full textAbstract:
碩士國立政治大學
經營管理碩士學程(EMBA)
98
In the fast growing IT world of today, Metal Injection Molding (MIM) technology transform the traditional manufacturing method of the metallic parts to a revolutionary fabrication process in the machinery industries. MIM actually has been developed for more than 30 years, and in the latest 5 years, the annual growth rate is about 10 to 15%. End products are commonly component items used in various industries and applications. Company P has been using powder metallurgical technology to produce auto parts. Although its business was affected by the slowdown of auto industries due to the financial storm in the second half of 2008, its advancement in the MIM technology, including the development of the energy saving material, had helped the company to survive in the downturn of auto industries. Another Company T in the case study has used the MIM technology to provide the diversified geometrically complex metal parts for more than 10 years. This study was using the tools of analysis and case studies to find the niche of metal injection molding industry for the enterprise to explore the appropriate managing strategies during they were developing and growing process of the business. The theoretical background of this study is referring to the industry analysis and 「Five Force analysis」 made by Professor Michael Porter of Harvard University in 1980 and 1985. It gives an overview and the overall environmental and competitive analysis and used for studying the development trend of the MIM industry. Using the SWOT matrix for strategy matching proposed by Weihrich in 1982, the company’s internal strengths, weaknesses and external opportunities and threats, could be analyzed and expressed in an explicit form. Then, maximize the strengths and opportunities and minimize the weaknesses and threats to define the present situation, and then develop the best applicable strategies for the company. Through industry analysis and case studies, this study concludes the followings: (1) Powder metallurgy and metal injection molding industry are affected by the global economic environment, oil prices and the technological advancement. (2) The life cycle of powder metallurgy industry is at its growth period, but the metal injection molding is at the end of embryonic period and moving to growth period. (3) Since it’s not easy to use the traditional fabrication process to make the complicated or asymmetric shaped metallic parts, the metal injection molding technology has the advantages of making the complicated parts with less fabrication steps. (4) Powder metallurgy and metal injection molding could continuously reduce costs and shorten the delivery time to increase their competitiveness. (5) The products could be widely used in various kinds of industry where the metallic parts are needed. Company P is producing one-third of the gears used in the world-wide auto industries and Company T is making the small and complex parts for the hand tools, 3C and IT industries with profits. Finally, the suggestions for metal injection molding industry are listed as follows: (1) Under the regulations of the environment protection, we should develop the energy conserving and carbon-reducing materials to meet the requirements. (2) China is developing the metal injection molding technology aggressively to meet the demand of its automobile market, which provides a great business opportunity of the auto parts supplier of Taiwan, (3) Since the life cycle of 3C and IT products is very short, the engineering team should design and fabricate the products in a very short time to the market. Also, it is necessary to use ERP management to reduce inventory and co-work with customers to develop products, conserve resources and reduce the risk.
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Jiun, Shu Guo, and 殳國俊. "High strength alloy steels for metal injection molding." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/36180711270518915802.
Full textAbstract:
碩士國立臺灣大學
材料科學與工程學研究所
89
Metal Injection Molding process is a new technology suitable for the fabrication of small parts with complex shapes. MIM-4605 low alloy steel is one of the materials recently available to the industry. It has better mechanical properties than Fe-2Ni（MIM-2200） and Fe-8Ni（MIM-2700）alloys. But, compared to the materials readily available for wrought metals, there is still much room for improvement. The objective of this study was, thus, to develop new alloys by adding high hardenability elements. This study used carbonyl iron powder as a base powder the mixed with elemental powders of Ni, Cu, Mo and Cr. The admixed powder was kneaded with 7wt% binder. The feedstock was injection molded, solvent debound in heptane, and then thermal debound in an argon atmosphere. The final sintering was carried out at 1200℃ in vacuum. The results show that the best tensile strength is over 1700MPa and its elongation is more than 2%, attained on Fe-1.75Ni-0.5Mo-0.4C. With Cu addition, the ductility decreases but with increased tempering strength. When Cr was added, the elongation increased but the tensile strength decreased. The sintering behavior was monitored by a dilatomter. The results show that phase stabilizer elements, such as Ni, decrease the phase transformation temperature and retard the exaggerated grain growth during phase transformation. But with too high a content, the density decreases and the tolerance control becomes difficult.
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Chai, Wei-Jie, and 蔡惟捷. "Applying Mold Filling Analysis in Metal Injection Molding." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/v45nbu.
Full textAbstract:
碩士國立高雄應用科技大學
模具工程系
103
In this thesis, the application Moldex3D mold flow analysis software package in powder injection molding PIM (Powder Injection Molding) of the modules to be metal powder injection molding MIM (Metal Injection Molding) simulation of the module to explore design changes and improvements of conduct Research programs to the exit in the product cavity in the flow balancing and metal powder distribution, through physical form and simulation database comparison, use physical similarities alternative materials 316L stainless steel powder (stainless steel 316LA) simulation of metal powder injection and Catamild 17-4PHX analog materials, the study discusses three parts, the first part of the application of this mold flow analysis techniques developed for multi-cavity system to verify, validate the contents of the pressure sensor of the system should be verified with the temperature curve via the second part is the use of different injection parameters influence on the product, the impact of content and be emitted into the surface of the embryo after the birth flow marks and product color verification than the case of a metal powder distributed via mold flow analysis, The third part is the use of three types of flow channel design of pressure and warpage.
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Chen, Huan-Xi, and 陳奐晞. "Mechanical Properties Analysis of Metal-Injection-Molding SKD11 Parts." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/58233813789325031741.
Full textAbstract:
碩士東南科技大學
機電整合研究所
100
The SKD11 powder was used to fabricate the components by the metal injection molding (MIM) process. The effects of sintering parameters, powder vendors, particles size and binders on the microstructure and mechanical properties of sintered components were analyzed in this study. Experimental results revealed the hardness and wear-resistance increased with an increase of sintering time. The powder fabrication by gas-atomization process was harder than those of water-atomization after sintered. A smaller particle size had superior microstructure, hardness and wear-resistance performance after sintered; however, dramatic fluctuations of friction force was observed in the specimen. The effect of binders to the mechanical properties of sintered parts was not apparent in this study. Addition of 10 wt.% iron powder to the SKD11 powder increases the hardness of sintered part, as well as reduceing the cost of powder.
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Huang, Hank, and 黃柏翰. "Numerical Simulations of Wick Debinding in Metal Injection Molding." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/53019517502787391377.
Full textAbstract:
碩士國立中央大學
機械工程研究所
93
Metal injection molding(MIM) is a method in metallurgy that combins the benefits from both plastic molding and powder molding. Its advantages include high capacity, high accuracy, low cost for mass production, capability in treating complicated shapes and insensitivity of material using. The removal of binder from the shaped metal or ceramic powder compact is the most consuming step in the powder injection, its many the source of defects in the manufacturing step. In order to reduce the duration of debinding, capillary extraction of the binder by wick powder may be employed. The study utilizes a two-dimensional netwok model to investigate the mechanism of wick debinding by the numerical simulation with a technique combining finite-difference and Monte Carlo methods, a local porosity distribution is quoted in the study, applicable local porosity distribution and typical length scales. Proper theoretical porosity distribution functions are adopted to fit the applicable local porosity distribution, according to the theoretical distribution function, a random number generator is used to generate data of porosity with quantitative randomness for numerical simulations. The typical length scale is an important basis for determining the size of the control volume. The result shows that the contours of wetting wick are irregular and the walking flow edges behave randomly, wick debinding time is proportional to the wick powder diameter and inversely proportional to the compact diameter. As well as the debinding time is proportional to the fractional debinding time.
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Zheng, Wen-Bao, and 鄭文堡. "The influence of the saturation in metal injection molding." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/59941192757965704555.
Full textAbstract:
碩士國立中央大學
機械工程研究所
90
Metal injection molding (MIM) is a method in metallurgy that combines the benefits from both plastic molding and powder molding. Its advantages include high capacity and high accuracy. In the MIM production processes, debinding is the most important and time-consuming stage Failing in this key process always leads to the overall failure of the MIM production. To analyze the global behavior of the two-dimensional wick debinding, we apply Darcy’s law and the finite difference technique combined with the body-fitted grid generation method. The influence of the saturation on the wick-debinding mechanism is included. The numerical method is used to simulate the probability of pressure field and predict the wick-debinding time is simulated. Results with/without the consideration of saturation are also compared.
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Liu, Chan-hung, and 劉展宏. "Mold Flow Analysis on Workpiece for Metal Injection Molding." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/80555956739972369104.
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碩士義守大學
機械與自動化工程學系碩士班
97
Metal Injection Molding is to improve the shortcomings of conventional powder metallurgy and Yan developed new technologies, can be used in the manufacture of products of complex shape, in the past affect the quality of their products, mainly relies on the experience and the cumulative number of times without trial and error. In this paper, mold flow analysis CAE to explore the use of simulation and numerical analysis methods, coupled with experiments to find the best process conditions and mold design. From the injection molding of pieces of common defects, analysis of its causes and to find out the response. The manufacturing process for forming into the material, filling, packing, compression, cooling, mold release parameters at various stages of control and experimental parameters such as flow design, materials, plastic melt temperature, filling time, filling pressure, such as impact, mold flow analysis through multi-dimensional considerations, to be assured of quality cases, to injection molding pressure pouring mouth parts and products minimum warpage, deformation, such as the minimum size for evaluating the choice of indicators. Ratchet Wrench by the system within the tooth is forming authentication example, you can improve the experience of the past heritage and the old trial and error procedures, to meet the present day abnormal crescent of the industrial sector in the product quality, speed, alcohol does the requirement.
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Li-Ming, LIOU, and 柳立明. "Optimum analysis of wick debinding in metal injection molding." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/10053200478963265240.
Full textAbstract:
碩士國立中央大學
機械工程研究所
87
Metal injection molding which procedure of manufacture is kneading which mix metal powder and binder to mould it, debinding and sintering. Besides it had distinction of powder metallurgy, complexity of shape and density of product of metal injection molding are better than powder metallurgy. The crux in all of process of metal injection molding is debinding, not only many kinds of defect are appeared but also cost increased when the process makes long time. The paper focus wicking of thermal debinding and analysis deeply by Taguchi method to find controllable factors to shorten debinding time and achieve well-quality. At last, we consider the exchange of quality and capacity of manufacture, we got the best combination of parameter in our experiment, A1B2C1D1. It indicated large particle size ratio, low viscous binder, spherical powder shape and homogeneous packing density.
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Yang, Chao Yuan, and 楊朝元. "Study on the Process of Metal Powder Injection Molding." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/42776679264036032847.
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碩士國立清華大學
動力機械學系
84
The purpose of this study is to make a systematic study on the process of the metal powder injection molding. The entire process consists of binder system selection, injection molding conditions selection, debinding profile''s setting, and effect of sintering atmosphere and temperature. In the experimentation, a standard binder system mainly consists of polypropylene, paraffine wax, carnauba wax, and stearic acid. The feedstock is made by mixture of the carbonyl iron with the standard binder system. The conditions of the injection molding are set up using the Taguchi''s Experiment Design for improve the green body quality. During the debinding process, the results show that debinding could be finished without defects when using multi- stages control with slow heating rate and temperature holding under nitrogen atmosphere. In the sintering process, temperature is more important than time, therefore the difference among the sintered bodies in microstructure are viewed under different sintering temperatures. These results show that higher tempera- ture sintering process produces a high density and desification level but coarser grain.
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Yeh, Hsin-Ya, and 葉欣亞. "Study of Metal Powder Molding by Using Injection Compression Technology." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/89381753343965805231.
Full textAbstract:
碩士中原大學
機械工程研究所
103
Metal powder injection molding (MIM) is a near net-shape manufacturing method combining plastic injection molding process with powder metallurgy process. Since MIM involves the widespread process characteristic, it often ends with unstable on product quality. Especially, the defect of warpage appears usually after the step of agglutination and de-binding result from the stress occurred in injection molding step. This study investigates the effect of injection compression molding to the traditional metal injection molding on the part density, hardness, flatness, and dimensional stability under several control factors. For this study, at first, the traditional metal injection molding experiment is conducted with different melted temperature, injection speed, mold temperature, and packing pressure for the density, hardness, flatness, and dimensional measurement on different part area of green part, brown part, and the final metal product. Further, the same measurement are checked for the synergy processes between metal injection molding and injection compression molding with several parameters included the gap of mold open, compression delay time, and compression clamping force. In the final, we compared with the part molded by traditional metal injection molding, the synergy process, and the one made by CNC process for the mechanical properties. The result shows that the optimized part properties for traditional metal injection molding are molded on the 200 oC melted temperature, 10% injection speed, 30 oC mold temperature, and 30% packing pressure. By this parameters combined with injection compression molding, it is learned that the greatest part properties are molded by the 0.9s compression delay time, 85bar compression clamping force, and 0.5mm of open gap. Moreover, the metal part density of synergy process is achieved 99.5% compared to the density of original stainless steel.
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Yang, Ming-Hsien Ou, and 歐陽銘賢. "Study of Metal Powder Injection Molding Using Gas Assisted Technology." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/tnasnj.
Full textAbstract:
碩士中原大學
機械工程研究所
106
Metal Injection Molding (MIM) is a manufacturing method combining with injection molding process and powder metallurgy process. De-binding process takes the longest time in all process. As the volume of product is large, it will take doubling time on de-binding process. Utilizing the gas-assisted injection molding (GAIM) can let the product be hollow. Therefore, the purpose of the study was to reduce the time on de-binding process by combining with GAIM and MIM. One dimensional tube was utilized to individually investigate the effect of gas assisted injection molding to the traditional metal injection molding on the part density, the hollowed-core ratio, penetration length and shrinkage under varied parameters. The parameters was including that gas pressure, gas holding time, gas delay time and mold temperature. The same measurements were checked for the synergy processes with different shot size after getting the lowest shot size by comparing the effect of different parameters. Besides, the injection pressure and de-binding time in gas assisted injection molding was also compared within different shot size, including full shot. The results of the study show that gas-assisted injection molding applied on metal injection molding can improve the defect of powder-binder separation, and reduce the shrinkage of green part. Because the product’s structure is hollow, the shrinkage by sintering can be reduced. The result of different weight percent show that the injection pressure can be reduced 17.23% in full shot when the shot size was sixty five weight percent, and the time of de-blinding can be greatly reduced.
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Chen, Ryan, and 陳裕元. "Experiment Observation and Analysis for Wick Debinding in Metal Injection Molding." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/60760698640261964898.
Full textAbstract:
碩士國立中央大學
機械工程研究所
93
In the mature technique of metal powder injection molding (MIM), debinding process plays the key role among the whole procedures. In the consideration of cost and performance of the products, many researches have been studied on how to improve the debinding procedure. In the article, the metal powder for industrial use, in stead of the steel ball, is adopted in the experiments. The debinding process is observed and discussed. Furthermore, the variation of the flow fronts as will as the quality of the products for different compact shapes and powder sizes are analyzed and compares with previous researches. By the clear statement of the debinding process and the indication of errors between experiment and numerical simulation, this paper may offer valuable reference for the future researches.
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Behi, Mohammad. "High solid loading aqueous base metal/ceramic feedstock for injection molding." Thesis, 2001. http://library1.njit.edu/etd/fromwebvoyage.cfm?id=njit-etd2001-110.
Full textAbstract:
Thesis (Ph.D) -- New Jersey Institute of Technology, Committee for the Interdisciplinary Program in Materials Science and Engineering, 2001.Includes bibliographical references. Also available via the World Wide Web.
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Lee, Chang-Hsien, and 李昌憲. "Study of Mechanical Properties for HIP Procedure on Metal Injection Molding." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/ws92m5.
Full textAbstract:
碩士中原大學
機械工程研究所
104
Hot Isostatic Pressing (Hot Isostatic Pressing, HIP) technology has been widely used in the foundry industry, because they can improve the strength of the cast material, ductility and fatigue life, strengthen internal porosity improve the casting process arising due to its manufacturing process combines high temperature and high pressure mode, the cast member after passing through secondary processing to obtain better mechanical properties. 316L stainless steel material used in the experiment, 3C products in electronic metal parts, the use of most metals emitted material, providing electronic 3C products need to light the space, while the strength of having the entire machine demand as superior corrosion resistance , strength, creep and fatigue characteristics, so that products in the high-temperature and low-temperature environment can have good mechanical properties. This study focuses on the hot pressing process are affecting the mechanical properties of stainless steel 316L MIM metal injection, MIM 316L stainless steel workpieces are introduced into the hot pressing process experiments using two different thermal equalizing temperatures include 1100 ° C, 1250 ° C; to Fixed heat equalizing pressure 175 MPa; fixed pressure and temperature for 1 hour sample formed two conditions, then with non-thermal equalizing workpiece mechanical properties than the right. Analysis to room temperature tensile tests, density, dimensions of change, etc., to assess the impact of hot pressing process are of stainless steel 316L.
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Lin, Yu-Yun, and 林毓源. "The Study of Injection Molding Machines with Automatic Metal and Plastics Integration." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/89480250308108637384.
Full textAbstract:
碩士國立彰化師範大學
電機工程學系
100
The study proposes an injection molding machine to integrate metal and plastic by automatically circulating injection and molding process. The main part of the injection molding machine is to equip a feeder and a discharger on the side of the working table. After locating few sets of molds on the working table, the first, second, third and fourth pneumatic cylinders equipped on the corners of working table sequentially move these molds into feeder to embed nails. These molds are then molded in the injection machine and moved into discharger to cut waste materials. The product is therefore completed. In the mean time, these waste materials are forwarded into a grinder to be shattered and then delivered into a material tank through a tube to be recycled. The experimental result proves that this automatic recycling procedure reduces up to 1/7 of labor cost and increase productivity by 150%.
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Wang, Tzu-Yi, and 王子怡. "The experiment and simulation of plastic injection molding product with metal insert." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/33155262768953453070.
Full textAbstract:
碩士國立高雄應用科技大學
模具系碩士在職專班
101
In my in-depth study of metal embedded in plastic injection molding and structural design of relationship. This research results provide the latest embedded product design basis. First use ABAQS finite element analysis software to analyze the different structures of the flexural deformation capacity and further analysis using Moldflow software in the same injection molding process parameters to analyzed the difference in structures. This verifies the reliability and practical control deformation to obtain the most stable structure condition. The original experimental thesis the inserts is thickness 0.3 mm warping deformation of 0.84mm. After the insert structural optimize and change the thickness to 0.4mm and the inserts after warping deformation to 0.20mm. It’s based on the cost and weight of design consideration to optimized design of the original insert with thickness of 0.3mm, by using Taguchi analysis software to define the optimal combination of Moldflow injections molding process parameters. In order to achieve the minimum amount of warping and products assembly requirements flatness fell 0.2mm or less. As the research results show adjust the mold temperature and melting temperature can effectively reduce the amount of Warping deformation , which changed the mold temperature to most influential factor.
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Chuang, Kuei-Lin, and 莊貴霖. "The Sizing Process of Metal Injection Molding on the Material Handling Automation." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/50936203279814696028.
Full textAbstract:
碩士輔仁大學
科技管理學程碩士在職專班
104
Metal injection molding (MIM) is one kind of process technology which is widely applied to electronics, medical, automotive, mechanical tool, aerospace, military, commodity, and so on. Under high temperature (about 1300 ℃) of vacuum sintering, parts would be deformed due to raw material and the size of objects. Sizing process will be next process to solve the problem of deformation in order to meet dimension tolerance request. The situation of labor shortage in tranditional industry is becoming worse. Therefore, introducing into the development of automation can not only enhance the working efficiency, but also train the staff expertise toward the development of industry 4.0. This study is to research the feasibility of the sizing process of MIM on the material handling automation. Design materinal handling contruction as per the sizing tool of the object. Plan two forms of material handling automation by sliding & mechanical arm. And, draw up the operating flowchart to anslyse working hours between manpower and machine. If working efficiency could be raised, evaluate the expection of efficiency by cost-benefit analysis. If the result of evaluation – NPV is larger than 0, that could be proved this material handling automation is worth investment. Then, implement the program to create a real machine and prove the performance. The empirical results can meet the expectation of working efficiency and cost benefits analysis. The NPV of material handling automation by sliding & mechanical arm are NT$ 5,844,712 & NT$ 3,805,577 which are proved very worth investment. Therefore, introducing into the automation can not only indeed streamline manpower but also reach the research of purpose. That’s a reference to MIM manufacturing enterprises who would like to promote the automation in order to enhance the core competitiveness of enterprises.
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Chen, Zhao-zong, and 陳昭融. "Implementation of A Hot Sprue into the Mold for Metal Injection Molding." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/69005208520651950596.
Full textAbstract:
碩士國立臺灣科技大學
機械工程系
98
Hot sprue systems are widely employed in plastic injection molding, but rare in metal injection molding. In this study, a home-made hot sprue was implemented into a mold for metal injection molding. Optimization of the injection molding variables was carried out using a Taguchi experimental design approach. The differences in hardness, density, dimensions, and appearance of the sintered components were compared for the molds using a hot sprue and a cold sprue systems. The results indicated that, within the processing variable window investigated, the working window for the mold using a hot sprue system was wider than that using a cold sprue system, especially in the molding pressure. The variation of a dimension of 24.59 mm ranges between 0.03 mm and 0.06 mm for the sintered components molded using a hot sprue system, while that ranges between 0.232 mm and 0.281 mm for the sintered components molded using a cold sprue system. In addition, the appearances of the sintered components molded using a hot sprue system were superior to those using a cold sprue system.
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Hsu, Hung-Chuan, and 許宏全. "The Study of Optimal Parameter Design in 316L Metal Injection Molding Process." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/82428043596754286545.
Full textAbstract:
碩士國立高雄第一科技大學
機械與自動化工程所
97
The study was focused on the optimization design of metal injection molding (MIM) process in order to obtain an ideal shape and product characteristics of MIM parts by remedying the defect which makes it hard to control dimensional tolerance in MIM parts after the part shrinkage in the sintering process. The method in this study was conducted throughout three experimental phases. The first phase aimed to search a suitable backbone polymer by combining 316L stainless steel powder with different backbone polymers. The second phase was targeted to find injection molding range by using injection temperature and injection speed as the control factors of the injection molding operation window. The third phase was concerned with searching the optimal parameter combination with multiple quality characteristics by means of the combination of Taguchi method and Principal Component Analysis (PCA) method. The results of the study showed that: (1) Use of HDPE backbone polymer could obtain better dimensional precision of sintered qualities (improved over 22% and 43% of length and width, respectively) than use of LDPE. In addition, it enhances the unity of density (improved over 23%) and hardness (improved over 62%). (2) In search of injection molding operation window, binder agglomeration and coarse powder resulting from lower and higher injection speed respectively made a harmful impact on sintering process at a later date. Only under suitable injection speed could the quality be controlled and increased. (3) The results suggest that the optimal parameter combination derived from the combination of Taguchi method and PCA method efficiently decrease sensitivity to all kinds of noises, reduces variability of multiple quality characteristics, solves the problem about dimensional tolerance in sintered parts which was hard to control, and increases the unities of density and hardness.
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Kao, Syuan-Yi, and 高軒羿. "The study of processing warpage for plastic injection molding product with metal insert." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/75067989122707346124.
Full textAbstract:
碩士逢甲大學
機械工程學所
99
The research to a steel insert external PC plastic coated to study for mobile phone cover made up of objects. Application of Taguchi experimental planning method used with Moldex3D mould flow analysis software, which reduce the number of experiments, study on injection molding conditions on the effects of warpage, thereby arriving at the minimum amount of warpage optimization of injection molding process parameters. Research have shown adjust the packing pressure and packing time to effectively reduce the amount of warpage, where packing pressure is the most influential factor. Original process parameters of CAE analysis of warpage for 1.700 mm and CAE analysis of warpage optimization parameters of 0.491 mm. Optimization of process parameters compared to the original process parameters to improve the 71.12% of warpage, Taguchi methods actually contribute to the planned experiment and parameter optimization.
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Kuo, Fang –. Jen, and 郭芳仁. "Uses the metal injection molding technology to make the 316L stainless steel parts." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/14472159632103390641.
Full textAbstract:
碩士國立勤益科技大學
機械工程系
98
The 316L stainless steel components for manufacturing paper study, research methodology metal powder injection molding technology manufacturing early sample blank, off the solvent and ester binder removal furnace has been off ester tofo placed into a vacuum furnace, the control temperature rate, increasing temperature and the critical parameters of the furnace under vacuum sintered into the highest porosity, the best strength of metal components. Most of powder metallurgy sintering technology of metal technology, said the highest component density, mechanical properties of the banks of the strongest, while the porous sintered metal technology is the test the other direction, the device has a porous sintered into the highest, the lowest density so that components with the highest degree for the purpose of ventilation. Porous components are used in filtration, separation, catalysis, put out flame, heat exchange and gas distribution industries Yong Tu, widely used in chemical, mechanical, metallurgical, pharmaceutical and food process, is a powder metallurgy techniques special applications, there is enormous potential. In this study, the impact of the porosity of porous materials, the factors detailed in the study done. Using 316L stainless steel powder material, powder fine of between 0~20μm.Select paraffin mixed polymer plastic material as the binder mixing granulation, using precise production of a thickness of 2mm steel cylindrical cup-shaped mold to melt metal powder injection molding machine metal powder particles, the beginning of injection molding of the sample blank shape. After the initial blank shape to be off by solvent, ester wax removal of binder components, and then removal of polymer components at high temperature furnace, and finally to multi-stage heating rate, sintering of metal material made of porous permeability. The results showed: de ester process and sintering of the temperature control and heating rates directly affect the porosity and pore size; the porosity, permeability metal porosity is the key feature, so it will be a system test, change the injection molding pressure, respectively,sintering temperature and the production of compact components with porous components.SEM observation of the sample made to change the surface pores to measure the proportion of measured changes in density and porosity to TGA test samples hot off the process of weight change of ester to testing machine components and mechanical properties in order to get to control the density, tensile strength, hardness and porosity, the porosity of the best parameters. According to multiple sets of different parameters to the results of comprehensive consideration of product porosity, strength, density and other factors, this study to determine the optimum production parameters for the injection molding pressure 1000kg/cm ^ 2, hot off ester temperature 800 ℃, 1200 ℃ sintering temperature , retention time 60 minutes, in such parameters obtained for 316L stainless steel porous materials, the highest porosity, high impact strength up to more than 70% dense material.
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Chung, Chin-Feng, and 鍾金峯. "The W-Ni-Fe Based Metal Powder Injection Molding Technique for Micro Cutter." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/78887621379518699886.
Full textAbstract:
碩士國立高雄第一科技大學
機械與自動化工程所
94
Abstract The research aims to investigate a good quality of micro cutter which is produced based on the metal injection molding technique and utilizing two different formula of W-Ni-Fe alloy combined with binder. Since the control of dimension and surface hardness to the sintered parts are always the key issues to be discussed in the metal injection molding processing, the Design of Experiment (DOE) technique is thus employed in this research to find out optimum processing parameters during injection molding and sintering processes. The research results present that the non-isotropic shrinkage degrees for MIM parts is decreased about 30% or above, surface hardness is around HRC45 and the overall shrinkage rate is controlled in the range of 26%~26%. In general, this research illustrates that the metal injection molding has potential to produce an accurate micro part coped with fine mechanical properties.
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Hsu, Hung-Lin, and 許弘林. "Study on the Process Characteristic and Part’s Quality of Metal Insert Injection Molding." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/12767628591794282516.
Full textAbstract:
碩士遠東科技大學
機械工程研究所
101
The objective of this research is to study and discuss the processing properties and part quality includes dimension change and residual stress of molding parts in metal insert injection molding. The mold of tensile specimen satisfied requirement of the ASTM 638 is used in the experiments. For this study, the molded part with near and far gate design, the insert part with ring shape design, and the molding resin with ABS, PA66, and PA66+GF33%. The metal insert injection molding parts are obtained by different processing parameters including injection speed, packing pressure, mold temperature, and melt temperature. From the experimental results, the residual stress, which decreases with increasing injection speed, mold temperature, and melt temperature；In another, it was found that a higher packing pressure will result large residual stress in which use near gate design the residual stress varies significantly around the insert part. From these data it is apparent that the dimension change of molded part due to uneven residual stress distribution. In addition, the dimension measurement of insert part by metal insert injection molding experiment will be measured using laser scan micrometers. During different processing conditions, the metal part has large deformation in Y direction. From the research results, it shows that the melt flow and temperature have significantly effect on product quality especial in Y direction.
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Cheng, Y. S., and 鄭育宗. "Numercal study on the two dimensional wick debinding of the metal injection molding." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/74151216211841620990.
Full textAbstract:
碩士國立中央大學
機械工程研究所
87
Metal injection molding (MIM) is a method in metallurgy that combines the benefits from both plastic molding and powder molding. Its advantages include high capacity, high accuracy, low cost for mass production, capability in treating complicated shapes and insensitivity of material using. In the MIM production processes , debinding is the most important and time consuming one. Failing in this key process always leads to the overall failure of the MIM production. To analyze the global behavior of the two dimensional wick debinding, we apply porous media theories and the finite element technique combined with body-fitted grid generation method. The variables which include binder viscosity , the size of the powder , the permeability and prorsity , control the debinding velocity , debinding time and the transform of the binder front . Although quantitatively, the result of simulation still is a great different with the experiment , The some conclusion is got , like that the external of the binder in the wick materal is similar with the one of the compact ,and the debinding time is the proportion with the area of the circle and quadrate compact .
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Chiang, Chang Po, and 張鉑強. "The analysis of mechanical properties for the products of metal injection molding using binders." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/14436414671910104541.
Full textAbstract:
碩士聖約翰科技大學
自動化及機電整合研究所
100
Although the metal powder injection molding technique is already widely used by the industrial community for the commercial mass production, each process of this manufacturing technique continues to have direct or indirect effects on the dimensions, mechanical properties, and appearance of parts. In recent years, the trend for the types of products manufactured by industries has gradually been converted into producing appearance accessory parts for 3C products. However, the technique still requires significant improvement in dimension and appearance control. Parts used by 3C products have strict dimension, mechanical properties, and appearance requirements. However, dimension variance issues still commonly occur after sintering during the manufacturing process. Consequently, additional processing methods are required to correct the dimensions, resulting in wasted manpower, material costs, and time. Current experimental results show that the dimensional stability of Products B and C sintered using binders with lower fluidity are fairly similar. The relative density of the sintered product from binder composition B was the highest at 95.2%. The hardness of the test piece produced from binder composition B was 5.47% to 5.69% greater than that of test pieces made from binder compositions A and C. Binder composition B also provided the optimal mechanical properties regarding tensile strength and yield strength. Combining the results in the various sections of this study, we found that the metal powder injection pieces produced from binder composition B had a relative density of 95.2%, a Rockwell Hardness (HRB) of 56.78, a tensile strength of 335.2 Mpa, and a yield strength of 115.4 Mpa; which comprise the best mechanical properties within the scope of this experiment.
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Lee, Xin-Yi, and 李信億. "Study on the Mechanical Properties of Bonding in Polymer and Metal Using Injection Molding." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/36990466938969569632.
Full textAbstract:
碩士龍華科技大學
工程技術研究所
96
Plastics with low cost, easily molding, and high precision are widely used in electronic, communication, sport, and mechanical parts. Sometimes, metal needed to be assembled with plastics, such as metal screws are labor fastened with plastic cover in mobile phone. It will be great benefited when metals and plastics are injected in one shot. This study is thus going to find the optimum process in one shot injection for metals and plastics. Metal parts will be drilled several holes to combine with plastics in current process. Local dents and worse quality will be appeared in bonding area of metal and plastic. This study discussed the bonding between plastics and metals. Selected materials included nylon, TPU, PMMA, PP, and metal. The strength of metal and plastic bonding with adhesive is employed to compare with that of no adhesive. This research studied the mechanical properties of bonding in polymer and metal using injection molding. Optimum bonding strength would be achieved when adhesive was added and surface roughness was improved. The results also showed that the strength of polymer/metal bonding was improved when rough surface was achieved in metal. The bonding strength of polymer /metal with coated aluminum powders was higher than that coated with glass powders.
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Liao, Chen-Li, and 廖偵利. "A Research of Technological Forecasting for Metal Injection Molding – An Example of “S Company”." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/t58ncy.
Full textAbstract:
碩士輔仁大學
科技管理學程碩士在職專班
102
Porite Chu (2011), in the journal of Bulletin of Powder Metallurgy Association, stated that the market development of metal injection molding in Asia is better than in Europe & America. According to BCC Research (referred to as BCC) market research report, Asia in 2014 of global metal injection molding market share is expected to exceed 50%. The compound annual growth rates in Asia from 2009-2014 is up to 15.8% superior to North America and Europe. Therefore, future development of metal injection molding in the Asian markets should not be underestimated. Metal injection molding is the technology with a larger developing space and high technological potential, however the life cycle of this technology could last longer or not. Examining the trend of its future becomes the motive of this study. “S company” is the object for this study. Growth curve and scenarios are main methods for technology forecasting, and comply with the analysis of technology strategy to be research methods of this study. Through technical analysis and discussion on future technological developments of metal injection molding, assess whether the metal injection molding technology can become the rising star of “S company”. Get three conclusions after analysis of “S company” case: (1) The development of metal injection molding industry can really look forward to the future, and (2) Find out the future development of S company in metal injection molding technology, and (3) Validation of metal injection molding technology can become the rising star of “S company”. Based on the best of unique opportunities, “S company” MIM should choose the right timing of market competition and establish technical standards to achieve market leadership. Those will be able to improve revenues & profits, and the annual turnover of “S company” MIM in near future will be unlimited.
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SHIH, YU-CHI, and 施鈺麒. "Research of applying stamping automation and polymer-metal joining to inserted injection molding processes." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/54929s.
Full textAbstract:
碩士國立高雄科技大學
模具工程系
107
This study is mainly to discuss the joint strength of the insert injection molding process, improve the general injection molding die to combine the metal stamping and injection molding process, and to discuss the influence of the physical properties of plastic on the join strength of polymer-metal parts, the matel part of inserts injection-molded on the market, and most of them are processed separately, and placed them in the injection machine to join, but most of them have larger product thickness. In this study, combines stamping and injection molding into one process, however, in order to finish the single process of injection and stamping, but the shrinkage rates of metal and plastic are different, the polymer-metal parts are often peeled off, so this study, manufacturing the small-scale structure on the surface of the matel, and use the shrinkage rate of the plastic to increase join strength, so that the metal can be more easily joined on the plastic. The experimental results show that when the metal surface of the anodized metal is joined to the plastic, the shrinkage different of the plastic part and the metal part may cause the polymer-metal are peeled of, but the small-scale structure which are manufacturing by laser engraving process are increases as the shrinkage rate, and the laser engraving process plastic materials are less restrictive in polymer-metal, even the processing time is much lower than the anode treatment process.
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Lee, Hong-Jen, and 李宏仁. "The effect of particle size on the solvent debinding in the metal injection molding process." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/11148581575111015909.
Full textAbstract:
碩士國立臺灣大學
材料科學與工程學研究所
86
This study investigated the influence of particle size on the solvent debindin g in the metal injection molding (MIM) process. Using the powderclassifier, 31 6L stainless steel and 1641 carbonyl iron powders wereclassified into several groups with different particles. The powderswere then kneaded with a three-com position binder. After injection molding,the parts were debound in n-heptane a t 50 degree C. Using scanning electronmicroscopy, laser dilatometer and the me rcury porosimeter, the microstructureevolution, pore size distribution and the in-situ dimensional changes duringthe sovent debinding were obtained. Transmi ssion infrared spectroscopy was also employed to understand the interaction be tween the stearic acid and themetal powder. The results showed that :1.For 316 L stainless steel, the bonding between the binder and the powder was very we ak and became the first region that the solvent attacked. It was found that the larger powder had a slower debinding rate which is different from that r eported in the literature. This was caused by its unique debinding mechanism. For 1641 carbonyl iron, the binder dissolution began at the binder itself an d the debinding rate for the 1641 carbonyl iron increased as the iron partic le size increased.2.For 316L stainless steel, the in-situ length change during solvent debinding of molded parts decreased with the increasing of powder pa rticle size.3.As a surfactant, stearic acid was well adsorbed onto the 1641 ca rbonyl iron powder but not onto the 316L stainless steel powder surface. With a new surfactant of Lica 12, the bonding was improved. Keywords: solvent de binding, metal injection molding, powder characteristics, surfactant, powder size.
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Chen, Yu, and 陳渝. "Study on the Density and Product Properties of Stainless Steel Metal Powder Injection Molding Process." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/8ypxgj.
Full textAbstract:
碩士中原大學
機械工程研究所
103
Metal Injection Molding (MIM) is a near net shape molding technology which combines plastic injection molding characteristics and powder metallurgy properties. Since MIM involves widely process: granulating, molding design, injection molding, de-binding, sintering and secondary processing, it is hard to have stable quality in final product. Especially, the warpage defect usually appears after de-binding and sintering, which is difficult to remedy. This study aims to improve MIM green part quality in injection molding step, enhance mechanical properties, and increase the productivity of a good final part as well as reduce the waste of material. This study uses several parameters, including melt temperature, injection speed and mold temperature. It measures density, tensile strength, and hardness of green part, brown part and final part in different regions, which are all made by stainless steel using MIM. By studying optimal final part quality through this experiment, it also helps to develop CAE simulation for MIM technology. The material formulation input into the material database in CAE software is established by material testing in advance. Furthermore, in order to compare the mechanical properties of MIM part with a real part made of stainless steel, a block of 316L raw stainless steel was cut in a shape of tensile specimen, same as its counterpart, using Computerized Numerical Control (CNC) cutting machine. These experimental results show that density, hardness, and tensile strength of green part, brown part, and final part are optimal using melt temperature at 200oC, injection speed at 10%, and mold temperature at 30oC. In simulation, metal powder density distribution trends under different settings are similar to experimental ones. Comparing the mechanical properties of MIM product to its CNC-cut raw steel counterpart, the product density, tensile strength, and elongation in MIM under optimized parameters can reach up to 98.7%, 99.0%, and 92.4% of raw steel, respectively. The aforementioned results indicate that MIM can produce a part with properties close to its raw metal product made by CNC.
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Tsai, Yi-Rong, and 蔡伊蓉. "The Integration of Activity Value Management and Machine Equipment Manufacture－A Case Study from Metal Injection Molding Company." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/wnjc3t.
Full textAbstract:
碩士輔仁大學
會計學系碩士班
107
The Activity Value Management System （AVMS） from Professor Anne Wu after years of research and developing out a management system to manage cells, has broken with the traditional accounting cost concept. This system provides information on a causal relationship to resolve the question as to the quality, capacity, and has accurate information that offers the manager to recognize improvement opportunities of the quality and capacity. This study to a case study combines with Activity Value Management System, and analyses this result of quality and capacity to provide the manager management implications and improvement suggestions. The case company is a metal injection manufacturing company that combines the manufacturing procedure and ERP data with Activity Value Management to obtain a series of analytical data that find the quality and capacity management problems of the case company. The results of the study found: （a） Controllable resources or uncontrollable resources are able to look out the degree of control of expenditure, （b） From the quality management show what the related activity on the quality will be given rise profit for a company, （c） From the capacity utilization rates show whether the activity process is reasonable, whether they need to improve, and （d） What are the profit or loss from individual products?
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Hsieh, Cheng-Chang, and 謝政璋. "Study on Flow Behavior and Quality Improvement of the Metal Powder Injection Molding by Using Gas Counter Pressure Technology." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/77647861690882058419.
Full textAbstract:
碩士中原大學
機械工程研究所
102
Metal powder injection molding (MIM) is a near net-shape manufacturing method combining plastic injection molding process with powder metallurgy process. Since MIM involves the widespread process characteristic, it often ends with unstable on product quality. Especially, the defect of warpage appears usually after the step of agglutination and de-binding result from the stress occurred in injection molding step. The purpose of this study is to establish the gas counter pressure(GCP) control, a matched mold, and implement it to the metal powder injection molding process. This study used a gas pressure of 50 bar and 100 bar, Then measure the mechanical properties and product quality. In the present study, the research of CAE is also carried out to help the mold design and understand the flow characteristics and proper mold design. Finally, we bring an original 316L stainless steel tensile bar by CNC process into comparison. The results show MIM make more uniform density distribution, GCP improve the uniformity of the product 59.96%,and powder-binder separation area reduced by 60%. Been in the other direction when the metal plunger pushed filling, making a more solid material shot during filling, Finally, we compare the original steel and MIM and MIM + GCP, and we found that the average tensile strength after sintering is increased 43.39%, elongation also increased 66.6%; adding GCP product density reached 99.1%.
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HUNG, CHUNG-CHING, and 洪仲慶. "Moldeling And Experimental Analysis Of Black Area And Weld Lines For The Guide Bush Of 17-4 PH Stainless Steel In The Metal Injection Molding." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/c9tsf5.
Full textAbstract:
碩士修平科技大學
精密機械與製造科技碩士班
105
The guide bush is the critical part of the sampling instrμments for medical minimally invasive surgery. The guide bush is made of stainless steel series and machined by metal injection molding. The common defects during metal injection molding process include short shot, jet phenomenon, crack, encapsulation, weld line, burr, warp, and black mark of which the weld lines and black marks have the most significant effect on the guide bush function. The defects will result in poor guidance by reducing mechanical strength and surface depression. Therefore, reducing the weld lines and black marks of metal injection molding can improve the functionality and quality of the guide bush. The study was focused on the optimization parameters of the metal injection molding on guide bush in order to reduce the weld line and black mark defects. The method in this study was conducted throughout three experimental phases. The first phase aimed to evaluate raw embryos produced during the molding process and analyze the molding factors and operating parameters. The second phase was targeted to obtain a set of optimized process parameter by conducted four numerical factors experimental design through the central synthetic experimental design method. The third phase was concerned with using the optimized process parameter to calculate the defective improvement. The results of the study showed: the optimization parameters of the metal forming process can reduce 78.81% and 83.85% of black mark and weld line respectively. In search of the model of the optimization parameters of the metal injection molding process can improve the product defect, and upgrade the product reliability.
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Chen, Chien-Hsiu, and 陳芊秀. "Comparison of corrosion resistance and surface characteristics of orthodontic bracket with same metal between one piece injection molding and soldering types." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/77915960267474763388.
Full textAbstract:
碩士臺北醫學大學
牙醫學系碩博士班
96
The ordinary orthodontic treatment would process for one year or longer. The metallic brackets would expose to a warm and humid oral environment for a long time and may suffer from corrosion. Corrosion may diminish the mechanical properties of the brackets and increase the wear rate, resulting in a poor orthodontic prognosis. Furthermore, corrosive ions release may cause adverse effects in the mouth, such as heavy metal toxicity, enamel discoloration or nickel hypersensitivity. The purpose of this study was to compare the changes of the surface morphology, ion release, and surface roughness of the 316L stainless steel brackets which were one piece injection molding type (group A), soldering type (group B) and soldering type without solder (group C) for various long time immersions in the artificial saliva under 37℃ at pH 7.0. These changes were observed by optic microscope (OM), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and detected by atomic force microscope (AFM) respectively. The ion concentrations of the artificial saliva were measured by inductively coupled plasma-mass spectrometry (ICP-MS). The results were analyzed statistically. The results demonstrated that after immersion in the 37℃ pH7.0 artificial saliva, the corrosion phenomenons were first detected in the 3rd month under OM observation. These phenomenons could be found over the edge of the wing, slot and base in both A and B group. However, the locations easily attacked by corrosion in group A were different from those in group B while group A were at the reflection corner and group B were at the border near the brazing joint and the base. Besides, corrosion attacks were more severe in group B than in group A. The three groups of brackets were mainly composed of Fe, Cr and Ni and group B had large proportion of gold over the brazing joint by EDS detection. As for the ions release, Fe, Ni and Mo release increased with time in the C group while Ni and Mo release increased with time in the B group. Ion release in the group A was relatively constant as the time went by. During the same period of time, Fe, Cr and Mo release revealed the most in the C group while Ni release revealed the most in the B group. There were no statistically significant changes of the surface roughness among the three types of brackets for the five months immersion. The group B brackets had higher surface roughness at the first and fourth month immersion groups, however, it revealed no statistic significance. The conclusion was that after immersion for five months in the 37℃ pH7.0 artificial saliva, the corrosion phenomenons were first detected in the 3rd month under OM observation. These phenomenons could be found over the edge of the wing, slot and base in both A and B group. However, the easily corrosive locations were different while group A were at the reflection corner and group B were at the border near the brazing joint and the base. Besides, corrosion attacks in group B were more severe than group A. Gold was the main element of the soldering alloy of the two pieces bracket. Comparing the ion release, Fe, Ni, Mo increased as the time went by. Among the three types of brackets, group C appeared to have more Fe, Cr and Mo release while group B appeared to have more Ni release. There were no obvious differences of the surface roughness during five months immersion test among the three groups of brackets.
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Chang, Po-Yao, and 張博堯. "Study on the Microstructure and Mechanical Properties of SUS-316L Stainless Steel by Adding TaC Powders Through a Metal Injection Molding Process." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/vka3y3.
Full textAbstract:
碩士國立臺北科技大學
材料科學與工程研究所
106
SUS-316L is a kind of austenitic stainless steel with has great corrosion resistance, making it one of the mostly used materials. It can satisfy general electronic parts requirements for magnetic property, corrosion resistance and appearance. However, SUS-316L stainless steel often cannot meet the requirements expected in regard to its mechanical properties. Metal Injection Molding (MIM) is a relatively new production method that can make a product with higher density and increased strength. Therefore, this study utilized the Metal Injection Molding (MIM) process to improve the sintered density and mechanical properties by adding TaC powder. In the present research, different ratios of metal powder and binder (93:7 and 92:8 wt%) were mixed and underwent various sintering at 1340°C, 1360°C, 1380°C and 1400°C, respectively. Moreover, the follow-up research added different ratios of TaC powders (1, 3 and 5%) to improve the properties of SUS-316L stainless steel. Finally, the mechanical properties and microstructure were inspected. The experimental results showed that the mixing ratio of 93:7 wt% of the metal powder and binder, and sintered at 1380°C possessed the optimal properties. Meanwhile, the sintered density was 7.65 g/cm3, hardness was HV0.5 134, tensile strength and elongation reached 540 MPa and 22%, respectively. In addition, TaC powders proved helpful in inhibiting grain growth (20.89 → 13.75 µm). Significantly, the optimal properties were obtained by adding 5 wt% TaC powder. The sintered density increased to 7.89 g/cm3, with hardness enhanced to HV0.5 170, while tensile strength and elongation increased to 548 MPa and 25%, respectively. Consequently, according to the above discussion and experimental results, the addition of TaC powder in SUS-316L stainless steel can effectively improve the microstructure and mechanical properties.
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LEE, PING-HSING, and 李秉興. "THE STUDY OF METAL INJECTION MOLDIND M2 HIGH SPEED STEEL." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/11136759455905565860.
Full textAbstract:
碩士國立臺灣大學
材料科學與工程學研究所
86
Abstract High speed steels made by powder m etallurgy have finer microstructure, better carbide distribution and mechanica l properties than the cast counterparts. However, the most popular high speed steel, AISI M2, has not been widely accepted by the the powder metal and metal injection molding industries due to its narrow sintering window and the poor dimensional control. To solve these problems, this study mixed three different pre-alloyed M2 high speed steel powders which were made by different atomizat ion techniques (designated as UFP, Pacific, and MHT) in order to broaden the s intering window. It was found that as the powder ratios were UFP : Pacific = 1 : 1 and UFP : Pacific : MHT = 1 : 1 : 1 , the sintering windows of these two powder systems were increased from 5℃ to 20℃. This is most likely caused by the difference in the compositions of the three powders, which resulted in di fferent liquid phase formation temperatures. The MIM process of M2 high speed steel has also been successfully developed. It was found that the debinding pr ocess increased the carbon content in the green compact system and lowered the sintering temperature of M2 high speed steel. The mechanical properties were comparable to those of the press-and —sintered compacts. Keywords: M2 high sp eed steel, metal injection molding, sintering window, dilatometry, powder char acteristics
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McCracken, Ivan A. "Processing bulk metallic glass from the molten state." Thesis, 2003. http://hdl.handle.net/1957/32612.
Full textAbstract:
This paper documents the investigation into injection molding, or die casting, a bulk metallic
glass (BMG). A BMG is an amorphous metal of a thickness greater than 25 ��m, according to
leading researchers in the field. This critical thickness differentiates a normal metallic glass from
a "bulk" metallic glass. The impetus for studying the ability to process lies in the material
properties of the BMG, which has twice the strength of steel and the ability to be formed much
like a thermoplastic. An initial discussion of processing options and history precedes a detailed
description of the machine concept and design, including the governing parameters placed on the
design. An account of methods and materials used has been included, along with problems
encountered and resultant remedies. The initial results consist of the verification of the machine
concept and the ability to replicate nanometer-sized surface features from a mold. Design issues
are addressed and the corresponding revisions described. The final machine revision shows an
increase in process repeatability. A presentation of photographs, which show results of forming
the BMG against both copper and stainless steel, is offered as a qualitative assessment of the
processing capability. A discussion of considerations and paths forward has been included for
future research using the machine that was developed, but these processing theories could also be
carried over to other experiments. In the end, this study proves the ability to form extremely
small surface features in cast BMG parts and makes suggestions on research avenues that may
give a better understanding of the variables involved in processing BMG from the molten state.Graduation date: 2003