To see the other types of publications on this topic, follow the link: Ball milling. eng.
Dissertations / Theses on the topic 'Ball milling. eng'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 31 dissertations / theses for your research on the topic 'Ball milling. eng.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Conceição, Flaviana Sales. "Efeito da hidrólise enzimática seguida da moagem em moinho de bolas sobre as características estruturais e físico-químicas do amido de madioquinha-salsa /." São José do Rio Preto : [s.n.], 2012. http://hdl.handle.net/11449/88373.
Full textAbstract:
Orientador: Célia Maria Landi Franco<br>Banca: Thais de Souza Rocha<br>Banca: Ana Carolina Conti e Silva<br>Resumo: Amidos modificados são utilizados pela indústria de alimentos por apresentarem melhor comportamento que amidos nativos. Modificações visando a redução do diâmetro granular para a obtenção de grânulos de tamanho similar aos da molécula de gordura tem sido de grande interesse, pois este amido modificado pode ser usado como substituto de gordura em diversas formulações. Para isso, o pré-tratamento enzimático pode ser usado para fragilizar a estrutura granular do amido e facilitar um posterior tratamento físico como a moagem, obtendo grânulos com menor diâmetro. O objetivo deste trabalho foi investigar o efeito da hidrólise enzimática seguida de moagem em moinho de bolas sobre as características estruturais e físico-químicas do amido de mandioquinha-salsa (Arracacia xanthorrhiza). Amido isolado de raízes de mandioquinha-salsa foi hidrolisado com α-amilase bacteriana e/ou amiloglucosidase fúngica, a 37 o C, em três diferentes condições: A: 40 SKB/g de α-amilase e 10 U/g amiloglucosidase por 36 h; B: 20 SKB/g de α-amilase e 5 U/g amiloglucosidase por 12 h; C: 5 U/g amiloglucosidase por 12 h. Após hidrólise os mesmos foram moídos por 1 e 2 h. Os amidos nativos e modificados foram analisados quanto à distribuição de tamanho de grânulos. Houve redução do diâmetro dos grânulos para todos os amidos tratados, mas a condição de hidrólise B foi a escolhida para a continuidade dos experimentos, por ter apresentado uma distribuição de tamanho de grânulos após moagem mais homogênea. Os amidos nativos e hidrolisados com 20 SKB/g de α-amilase e 5 U/g amiloglucosidase por 12 h foram analisados quanto a forma dos grânulos, distribuição do comprimento das cadeias laterais da amilopectina, distribuição do tamanho molecular dos componentes do amido, teor de amilose, difração de raios-X... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: Modified starches are used by food industry because they have better performance than native starches. Modifications in order to reduce granular diameter to obtain granules of similar size to those of fat molecules has been of great interest, for this modified starch can be used as a fat substitute in various formulations. For this purpose, a enzymatic pretreatment can be used to weaken the granular structure of starch and facilitate a subsequent physical treatment such as grinding. The objective of this study was to investigate the effect of enzymatic hydrolysis followed by milling in a ball mill on the structural and physicochemical characteristics of Peruvian carrot (Arracacia xanthorrhiza) starch. Starch isolated from roots of Peruvian Carrot was hydrolyzed with bacterial α-amylase and fungal amyloglucosidase at 37 °C in three different conditions: A: 40 SKB/g of α-amylase and 10 U/g amyloglucosidase for 36 h; B: 20 SKB/g of α-amylase and 5 U/g amyloglucosidase for 12 h; C: 5 U/g amyloglucosidase for 12 h. After hydrolysis, the starches were ball milled for 1 and 2 h. The native and modified starches were analyzed for granular size distribution. There was reduction of the granular diameter for all modified starches, but the B condition of hydrolysis was choosen to continue the experiments because the starches modified in this condition displayed a more homogeneous granular size distribution after milling. The native and hydrolyzed with 20 SKB / g of α-amylase and 5 U / g amyloglucosidase for 12 h starches were analyzed for granule shape, distribution of branch chain length of amylopectin, molecular size distribution of the starch components, apparent amylose content, X-ray diffraction, thermal and pasting properties, swelling power and solubility. The native starch granules, analyzed in optical microscope... (Complete abstract click electronic access below)<br>Mestre
2
Cavallini, Carolina Melki. "Estudo da modificação ácido-etanólica do amido de mandioca seguida de moagem /." São José do Rio Preto : [s.n.], 2009. http://hdl.handle.net/11449/88404.
Full textAbstract:
Orientador: Célia Maria Landi Franco<br>Banca: Magali Leonel<br>Banca: Mieko Kimura<br>Resumo: O tratamento ácido-alcoólico tem sido proposto para modificar a estrutura do grânulo de amido e obter a máxima conversão de amido nativo em amido solúvel. Este amido modificado torna-se frágil quando submetido à moagem em moinho de bola produzindo pequenos cristais que podem ser usados como substitutos de gordura. Neste trabalho, características físico-químicas, estruturais e morfológicas de amidos tratados com ácido-etanol (0,36% HCl em etanol anidro por 1 e 12 h a 30, 40 e 50oC) submetidos ou não a moagem em moinho de bola por 1 h foram analisados e comparados. A recuperação dos amidos foi alta atingindo em média 98%, independente do tempo e temperatura de tratamento. A solubilidade aumentou com o aumento da temperatura e tempo de tratamento e os amidos tratados a 40oC/12h e 50oC/12h tornaram-se totalmente solúveis a 95oC. O tamanho médio dos grânulos de amido de mandioca reduziu com o aumento do tempo e da temperatura de modificação, passando de 25,2 mm para 20,0 mm após 12 h de tratamento a 50oC. A moagem reduziu o tamanho médio dos grânulos de amido nativo e daqueles submetidos a tratamentos ácido-alcoólicos mais brandos (1 h a 30 ou 40oC), enquanto o tamanho médio dos grânulos tratados por 12 h, independente da temperatura, permaneceu inalterado. Os grânulos de amido de mandioca, observados em microscópio eletrônico de varredura, apresentaram forma arredondada e após tratamento com ácido-álcool a 50oC por 12h antes e após moagem, mostraram superfície áspera e rugosa sugerindo erosão com conseqüente solubilização das camadas mais externas dos grânulos. Alguns grânulos mostraramse disformes sugerindo gelatinização parcial que foi mais intensa após moagem. O índice de cristalinidade relativa (IC) dos amidos, determinados por difração de raios- X, aumentou quanto maior o tempo e temperatura de tratamento, enquanto o teor de amilose... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: Acid-alcohol treatment has been proposed to modify starch granule structure and obtain maximum conversion of raw starch into soluble starch. Acid-alcohol starch becomes fragile when submitted to the milling in ball mill producing small crystals, which can be used as fat substitute. In this work, physicochemical, structural and morphological characteristics of acid-ethanol cassava starch (0,36% HCl in anhydrous ethanol during 1 and 12 h at 30, 40 e 50oC) followed by milling in ball milling for 1 h were analyzed and compared. The recovery of the modified starches was high reaching 98% independent of time and temperature. The solubility increased with increasing of the treatment temperature and time, and after 1 h at 50ºC the modified starch became totally soluble to 95ºC. The average size of the cassava starch granules decreased with increasing of the treatment time and temperature from 25.2 µm to 20.0 µm after 12 hours of treatment at 50ºC. The milling decreased the average size of the native starch granules and those submitted to milder treatments (1 h at 30 or 40oC), while the average size of the starch granules treated for 12 h, independent of temperature, kept unchanged. From scanning electron microscopy, the native cassava starch granules presented round shape and smooth surface. After acid-ethanol treatment at 50oC for 1h, before and after milling, the granules displayed rough and exfoliated surfaces suggesting erosion with solubilization of the outer layer of the granules. Some granules treated at 50oC during 12 h showed deformed surfaces suggesting partial gelatinization of the starch that was more intense after milling. Relative crystalline index (CI) of the starches, determined from X-ray diffraction, increased with increasing of the treatment time and temperature, while the amylose content, intrinsic viscosity and pasting viscosities decreased... (Complete abstract click electronic access below)<br>Mestre
3
Lazoğlu, İsmail. "Analysis of force system in ball-end milling." Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/16022.
Full text
4
Tuysuz, Oguzhan. "Prediction of cutting forces in three- and five-axis ball-end milling with tool indentation effect." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/40071.
Full textAbstract:
In machining, the desired final shape is created in Computer Aided Design (CAD) environment and this information is forwarded to Computer Aided Manufacturing (CAM) phase in which the toolpath is generated and converted to machine specific commands for part manufacturing. The steps in CAD/CAM environments are geometry dependent only, and do not include the physics of the process. However, mathematical modeling of the machining operation gives the flexibility of identifying and resolving process related issues i.e. tool breakage, chatter vibrations and tolerance violations beforehand, which in turn leads to increased productivity.
The first step of process modeling is to model the mechanics of the operation that leads to the prediction of the cutting forces experienced by the cutting tool and the workpiece. In this study the mechanics of ball-end tool which is commonly used to machine parts with free-form geometric features are studied. The main problem in ball-end milling mechanics is tool indentation which leads to inaccurate force prediction in tool axial direction, and has previously been solved experimentally only for specific cases. This thesis presents a generalized ball-end tool indentation detection and indentation force prediction model for any kind of work material and cutting tool geometry combinations. The static ball-end milling forces with indentation forces are predicted by developing an analytical cutting edge indentation model. The proposed model utilizes indentation mechanics of punch and wedge shape indenters, describes the required conditions for indentation occurrence and evaluates plastic and elastic contact pressures at the cutting edge and workpiece interface using the material properties of the workpiece.
Cutting edge indentation mechanism is also studied through finite element (FE) modeling. A general FE model is obtained for the problem and results are reported only for the material cut in the thesis.
The model proposed in the thesis has been verified experimentally. After integrating the developed indentation force prediction model into the cutting force model, predictions in tool axial direction are improved by 15-40% depending on type of the operation. The contribution of the thesis can be used in cutting force based ball-end milling process optimization and analysis for industrial applications.
5
Feng, Hsi-Yung. "The prediction of cutting forces and the resulting machining errors in the ball-end milling process /." The Ohio State University, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487847761307671.
Full text
6
Lim, Ee Meng. "The prediction of dimensional errors and machining planning for sculptured surface productions using ball-end milling /." The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487862399449007.
Full text
7
Rodriguez, Ciro A. "Ball-nose end milling-development of criteria for automatic selection of spindle speed and feed rate /." The Ohio State University, 1997. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487947501133616.
Full text
8
Escolle, Bérenger. "Optimisation des outils de micro-fraisage destinés à l'usinage des aciers durs : cas des micro-fraises hémisphériques." Thesis, Besançon, 2015. http://www.theses.fr/2015BESA2023.
Full textAbstract:
L’objectif de ces travaux de thèse est l’optimisation par une approche expérimentale d’un modèle de micro-fraise hémisphérique en carbure de tungstène revêtu, de diamètre 0,5 mm, destiné à l’usinage des aciers durs. Les données expérimentales obtenues résultent donc de l’usinage d’un acier 40NiCrMo16 à l’état trempé (54 HRC). Les résultats permettent de mettre en évidence certains phénomènes de coupe, d’usure et de comportement dynamique de l’outil liés au procédé, et leur évolution en fonction du type de fraise considéré et des conditions de coupe choisies. La géométrie de l’outil et son comportement dynamique sont ici principalement commentés. Dans un premier temps, l’étude de différentes nuances de carbure, préparation de surface ainsi que l’optimisation des géométries globale et locale des micro-fraises a permis de proposer un modèle optimisé pour notre partenaire outilleur Magafor. Dans un second temps, une approche numérique du micro-fraisage a été utilisée. Un premier modèle de calcul analytique des efforts de coupe a été testé et il a été mis en évidence les limites d’identification des coefficients spécifiques de coupe dans notre cas. Ensuite, une modélisation numérique par éléments finis du micro-fraisage a été réalisée afin d’appréhender l’étude du comportement dynamique des micro-fraises en fonction de la géométrie globale de l’outil développé<br>The aim of this PhD work is optimized by experimental approach with 0.5 mm diameter micro-ball-end mills made from micro-grain tungsten carbide and PVD coated for hardened tool steels machining. The experimental data are obtained on machining of hardened steel (54/55HRC), typically used for the production of plastic injection molds. Results permit to highlight some cutting phenomena of wear and dynamic behavior of the process related tool, and changes depending on the type of milling considered and selected cutting conditions. The geometry of the tool and dynamic behavior are primarily discussed here. As a first step, the study of different carbide grades, surface preparation and optimization of global and local geometries of micro-cutters helped provide an efficient model for our partner Magafor toolmaker. In a second step, the modelling of micro-milling is discussed and an analytical model for cutting forces calculation is introduced. It was demonstrated the identifying limits of the specific cutting coefficients in our case. Then, a test of finite element modelling of micro-milling is made in order to estimate the potential of such a method for the study of the dynamic behaviour of micro-mills
9
Vlastimir, Pejić. "Modelovanje i optimizacija procesa glodanja vretenastim glodalima." Phd thesis, Univerzitet u Novom Sadu, Fakultet tehničkih nauka u Novom Sadu, 2016. http://www.cris.uns.ac.rs/record.jsf?recordId=100916&source=NDLTD&language=en.
Full textAbstract:
Proces glodanja tvrdih (kaljenih) čelika, vretenastim loptastim glodalima,najčešće se primenjuje u operacijama završne obrade kompleksnihpovršina. Modelovanje ovog procesa i optimizacija njegovih parametara suveoma važni, kao pomoć za razumevanje samog procesa tako i za rešavanjepraktičnih problema. Za modelovanje izlaznih performansi procesa obradei nalaženje optimalnih vrednosti ulaznih parametara, korišteno jenekoliko klasičnih i prirodom-inspirisanih metoda. Od klasičnih metodamodelovanja i optimizacije, u radu su primenjene: metodologija odzivnepovršine-RSM, Taguči metoda i Taguči metoda sa sivom relacionomanalizom. Korištene prirodom-inspirisane metode modelovanja ioptimizacije su: genetski algoritam–GA, sivi vuk optimizer–GWO inedominantno sortirajući genetski algoritam II–NSGA II. Dobijeni pouzdanimatematički modeli izlaznih performansi procesa obrade i optimalniulazni parametri obrade, potvrđuju opravdanost primene svih navedenihmetoda u procesu glodanja vretenastim loptastim glodalima tvrdih(kaljenih) čelika. Posebno treba izdvojiti rezultate dobijene pomoću metodesivi vuk optimizer–GWO. Ova prirodom-inspirisana metoda je potpuno novametoda i do sada nije bilo literaturnih informacija o mogućnostima njeneprimene u procesima obrade rezanjem.<br>The ball end milling process of hard (hardened) steel, is usually applied in thefinishing operations of machining comlex surfaces. Modeling of this process andoptimization of its parameters are very important as an aid to understanding theprocesses and to solve practical problems. Several classic and nature-inspiredmethods were used for modeling of the output process performances and findingthe optimal values of input parameters. From traditional methods of modeling andoptimization Response Surface Methodology-RSM, Taguchi method and Taguchimethod with Gray Relational Analysis, and nature-inspired methods of modelingand optimization Genetic Algorithm-GA, Gray Wolf Optimizer-GWO and NondominantSorting Genetic Algorithm II- NSGA-II, were applied in the paper. Reliablemathematical models of the output process performances and the optimal inputparameters, confirm the validity of the application of these methods in the processof ball end milling hard (hardened) steel. The results obtained by the method of theGray Wolf Optimizer-GWO should be particulary noted. This nature-inspiredmethod is quite a new method, and so far there was no literature information onthe possibilities of its application in the cutting processes.
10
Dvořáček, Jan. "Analýza silového zatížení řezného nástroje při pětiosém frézování." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228829.
Full textAbstract:
The diploma thesis is focused on machining using the ball-end shank mill. Content of the preliminary part of the work is a shank mill characteristic and a consequent part shows a splitting of ball-end milling cutters, its application, the cutting tool geometry and a characteristic signs of machining. The cutting force model of the ball-end mill is presented as well. A part of proposed model is the conversion of the resultant force too. Practical part is aimed at cutting force analysis of the ball-end mill and the main purpose of this part is a quantification of the cutting force for different work piece tilt angles while milling is performed.
11
Chen, Cheng-Yi, and 陳政億. "Analysis Model of Ball End Milling Forces for Inclined Plane Milling." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/fsr3w9.
Full textAbstract:
碩士<br>國立臺北科技大學<br>製造科技研究所<br>94<br>This paper proposes a mechanistic ball end mill cutting force model to estimate the ball end milling forces for inclined plane milling. The developed model that calculates the cutting forces based on a set of cutting force coefficients which depend on the material, the tool, the cutting conditions, the machining directions and the inclined angle of the milling surface. The developed ball end milling force models for inclined plane milling include rise milling ,downhill milling, and horizontal milling.
This study uses the present cutting force model and the measured ball end milling forces data to obtain equivalent specific cutting force coefficients (C , C , and C ) for some cutting conditions. By substituting the cutting force coefficients into the present ball end milling force model, the milling force variation both on horizontal plane and inclined plane can be predicted. Finally, the present study also construct some parametric Bezier surfaces of cutting force coefficients in the CAD system by using finite experiment data of ball end milling, which is used to easily find out the cutting force coefficients for any inclined angle of ball end milling operation. In the present study, the cutting force model has been tested on aluminum alloy Al7075-T6 with micro grain carbide ball end mill ( 10 - 2 flutes). Validation tests have been carried out on planar surfaces milling and on inclined plane milling in some typical ball end milling conditions. The results show that the predicted cutting forces agreed well with the measured cutting forces.
12
Lu, Chien-Hsing, and 呂建興. "Analysis of Surface Roughness for Ball-End Milling." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/49287011008746817972.
Full textAbstract:
碩士<br>逢甲大學<br>機械工程學所<br>100<br>Surface roughness is one of the most important performance indices for precision machining. This thesis presents an analysis on the effects of cutting parameters on surface roughness in ball-end milling process. The surface roughness in both feed direction and transverse direction is investigated. The cutting parameters include the feed, the spindle speed, the path interval, and the angle between the surface normal and the tool axis. In the study, 13 and 19 sets of data are conducted to establish empirical models for surface roughness in the feed and the transverse directions, respectively. Based on the proposed model, we can predict the surface roughness, design the tool paths and cutting parameters, and consequently, improve the machining quality and efficiency.
13
Lee, Shu-Yu, and 李書瑜. "Conic Lens Fabrication by Ball-End Milling Process." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/40872890886075129256.
Full textAbstract:
碩士<br>逢甲大學<br>機械與電腦輔助工程學系<br>102<br>By ball-end milling processes, mold of conic lens is fabricated on steel surface. With the plastic materials being heating to melt and filling the mold, conic lens is formed as plastic material cooling and solidifying.
Quantitative analysis by laser image is investigated. Different incident angles will produce different images. The lens can change the laser spot to line image. It shows the conic lens has function of cylindrical lens. Moreover, it can further split the laser spot to cross line image which is “X” shape. It is obvious that the conic lens has various functions which belong to lenses having different conic surfaces respectively.
From this study, it is found that CNC machining can fabricate conic lenses successfully. It can be used to machine lenses with complex surface practically.
14
Wang, Wen-Tsai, and 王文財. "Study of the Effects of Milling Parameters on the Ball-End Milling Forces." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/71691953705838164440.
Full textAbstract:
碩士<br>國立成功大學<br>製造工程研究所<br>88<br>In this thesis, the effect of milling parameters on the ball-end milling forces is investigated by both the theoretical and experimental methods. In experimental aspect, the instantaneous cutting force signals and average cutting forces with different milling parameters in three orthogonal directions were measured by piezoelectric dynamometer.
The objective of this thesis is to establish an algebraic model of cutting force system in the ball-end milling process. This objective is accomplished by systematically and analytically formulating the dominant dynamic components of three-dimensional cutting forces in the machining with helical multi-flute ball-end milling cutters. In this study, the ball-end milling cutting force model is developed to predict the instantaneous cutting force on given machining conditions. The basic concept involved in this thesis is the mathematical characterization of the cutter-workpiece interactions in terms of the chip width density function in an angular convolution expression. After the chip with density function is determined through the geometric model of cutter and workpiece engagement, differential cutting forces in three orthogonal directions are written in the angular domain. This solution is carried out by the convolution integration of the differential cutting forces along the helical flutes. A Laplace transformation for the convolution integral leads itself to a set of closed form expressions of the dynamic cutting force components in terms of process parameters, tool geometry, material characteristics and machining configuration.
Finally, the tangential cutting pressure constant, proportionality coefficients and the estimated cutting forces were computed by the measured average cutting forces. It demonstrated that the theoretical results agreed well with the experimental results.
15
Shuei-De, Chou, and 周水德. "The Analysis of Statistical Model of the Milling Force in Ball-End Milling Operations." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/47745720085238415263.
Full textAbstract:
碩士<br>大同工學院<br>機械工程研究所<br>86<br>The purpose of this research is to investigate what kind of cutting parameterswould affect the milling forces, when we use the ball-end milling cutter tomachine the free-form surfaces. The statistical experiment method is utilizedto establish the milling forces model of ball-end milling cutter and toinvestigate the effects of cutting parameters on milling forces withindifferent cutting conditions in accordance with the milling force models.The experimental results show that the milling force models are of goodreliability.In this study, the experimental design is adopted to plan the experiment.The experimental factors, including spindle speed, feed, axial depth of cut,radial depth of cut and position angle, are taken into consideration toinvestigate the effects on milling forces. In the experimental design, thematrix is planned by means of Response Surface Methodology and Taguchi Method.The experimental results are analyzed by statistical software package.Firstly, the experimental results which are analyzed by the analysis ofvariance can be practiced to assess the prominence among experimental factors.And then utilizing a second-order mathematical model, which is called canonicalanalysis, to model the mathematical relationship between cutting conditionsand milling forces. It is anticipated that the model is able to predictmilling forces over a wide variety of cutting conditions. The experimentalresults show that those significant factors, which will affect the millingforces, are in sequence to be the axial epth of cut, spindle speed,position angle and finally the feed rate. The model is also proved in goodagreement with experimental results. Finally, an optimum method is adoptedto search the optimal cutting conditions in the process of machining free-formsurfaces. These results are to provide the process planner with a guidance inselecting machining conditions.
16
Hung, Ming-Hung, and 洪銘宏. "Identification of Cutting Force Coefficients in Ball-End Milling Process." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/11223385349004487547.
Full textAbstract:
碩士<br>國立中正大學<br>機械工程所<br>94<br>The critical part industry in mold, automobile manufacture and aircraft industry are developing vigorously. The geometry of a workpiece is getting complicated and the requirement for the precision of the workpiece surface is upgrading. And the surface precision is directly influenced by cutting forces, so the investigation of the cutting force becomes an important issue. Thus, the aim of this study is focused on the cutting force coefficients identification and the predicted of the cutting forces while the milling test is performed with Aluminum 6061-T6 which is in common use.
In this study, the Taguchi Method is used to design the cutting tests. The effect of the feed per flute on the cutting forces is analyzed via the experimental results. The cutting force coefficients are identified by the Recursive Least Square Method with the experimental results of the end mill. The cutting parameters of AL6061-T6 are predicted by the identified cutting forces coefficients. Finally, the cutting forces in ball end mill are predicted by the model proposed in [9] with the predicted cutting parameters of AL6061-T6. The numerical results are compared with experimental results, and some conclusions are summarized as follows:
The results show that the cutting forces for end milling process can be successful predicted by using the identified cutting force coefficients. And the predicted forces are very close to the measured forces. Furthermore, the cutting parameters of Aluminum 6061-T6 can be determined and used to predict the cutting forces in ball end milling process. And the predicted cutting forces are conformed to approximate to the measured forces.
17
Hood, David Wayne. "Force feedback control of tool deflection in miniature ball end milling." 2003. http://www.lib.ncsu.edu/theses/available/etd-05202003-004124/unrestricted/etd.pdf.
Full text
18
Wang, Hsin-Chih, and 王信誌. "An Investigation on the Surface Roughness of Helix Ball-End Milling." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/05341246572344488868.
Full textAbstract:
碩士<br>國立中興大學<br>機械工程學系<br>93<br>Free surface has been widely employed in industrial products in recent years. Therefore, the ball-end milling technique for machining free surface is becoming more important. As surface roughness is a crucial index of free surface, this thesis focuses on the analysis of surface roughness by ball-end milling. Theoretical analysis of surface roughness based on the motion of cutting edges is first investigated. Experiments to verify the theoretical model are also designed and conducted. The differential geometry is employed to model the cutting edges of the helix ball-end cutter. The trajectory of the cutting edge is then derived from the rotation and translation of the ball-end mill. Based on the trajectory, we derived the theoretical model of surface roughness. To verify the theoretical model, three materials with different hardness Al-6061 aluminum alloy, NAK-80 molding steel and SKD-11 alloy steel are machined by ball-end cutters with different cutting parameters through a high-speed horizontal machining center and a vertical machining center. Experimental results showed that errors between the theoretical model and experimental data in Ra are less than 85%, while those in Rmax are between 25% and 318%. Although it implies that the derived model needs further improvement, this result is much better compared with the errors 422% to 2000% in literature. In addition, experimental results also showed that the surface roughness of ball-end milling by helix cutting edge behaves better than that by straight cutting edge. Furthermore, as the hardness of the material increases, the experimental result fits better to the theoretical model.
19
Liu, Nai-Kang, and 劉乃綱. "Research of the Tool Wear Analysis for Micro Ball End Milling Process." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/575jnu.
Full textAbstract:
碩士<br>國立高雄第一科技大學<br>機械與自動化工程所<br>96<br>Micro-ball-milling process has many advantages, such as generating complicated surface, high precision, highly surface roughness workpice, and low manufacturing cost. Tool wears rapidly due to it’s dimension especially when hardened material is to be milled.Propose,only limited regardy with control of the tool wear is a key factor of micro-ball-milling process.The influention factor affected tool wear should be identified for better performent of the operation.
The main objective of this research is to study the key factor and tool wear mode for milling harden mold steel with micro-ball-end-milling . In this research ,micro-ball end-milling is assured to be similar to grinding process,hereby the related theorem is found in the literature can be applied to describe micro-ball-end-milling.Geometric slidy coefficient to tool wear condition for the micro- end miller was proposed based on grinding force theorem.A milling experiment was through executed to terify the suitability of grinding theorem assumption milling force was collected and analysed during the experiment to observe the variation of the extracted geometric slidy coefficient.
It was found that geometric slidy coefficient can effectively describe the tool flank wear most of the experiment condition.A dimensionless analys was also performed to found out the key factor to affecting the variation of geometric slidy coefficient.Final a model to describe geometric slidy coefficient was also custuveted with two dimensionless parameter.
20
Chang, Yu-Jui, and 張祐睿. "CNC Machine Tool Surface Interpolator for Ball-End Milling of Free-Form Surfaces." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/86530668672143431693.
Full textAbstract:
碩士<br>逢甲大學<br>機械工程學系<br>88<br>Because of so many problems in the traditional CNC machine tool interpolator design, this paper presents a new type of it that is capable of generating the cutter path for ball-end milling of a free-form surface. The surface interpolator comprises three major points as follows: On-line algorithms for cutter-contact CC path scheduling, CC path interpolator, and tool offsetting. There are three kinds of interpolator algorithms, iso-parametric, iso-scallop and iso-planar respectively. The proposed surface interpolator gains the advantages for minimizing the data feeding to the CNC machine tool and maintaining the desired feedrate and more position accuracy along the CC path.
21
Sun, Jia-Cheng, and 孫嘉呈. "Study on the Optimization of Micro Ball-End Milling Parameters by Taguchi Method." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/47234331681765981046.
Full textAbstract:
碩士<br>國立臺灣科技大學<br>機械工程系<br>104<br>Micro-cutting plays an important role in advanced manufacturing because of the required tiny components. As a result, there is need for MEMS to be more functional, smaller and smarter. Aluminum is commonly used all over the world because it is much lighter, easy to machine and has good appearance. In 1950, titanium was discovered which has high strength, corrosion and heat resistance, but it is difficult and high cost to machine. Previously cutting parameter optimization were based on experience of machinist. The optimization based on machinist experience is not a scientific skill, so it resulted in tool and machine damage.
This study investigate cutting parameters using micro ball-end mill on aluminum and titanium. The factors considered includes cutting direction, spindle speed, depth of cut, spindle angle and feed rate. The Taguchi method was used to analyze and find the optimum cutting parameters to achieve minimum tool wear and surface roughness. The experimental results show that spindle angle has great effects on surface roughness and tool wear is highly depended on cutting direction. We can achieve good surface roughness by using constant and small cutting force.
22
Huang, Yen-Ming, and 黃彥銘. "An analytical method to determine cutting force coefficients in micro ball end milling." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/08626174389192987983.
Full textAbstract:
碩士<br>國立高雄應用科技大學<br>機械與精密工程研究所<br>102<br>The micro ball-end milling is an important technique for processing 3D free surfaces of tiny part. The change of specific cutting force coefficients can be determined by utilizing the process of measuring cutting force, thus appropriate adjusting the process parameters of micro ball end milling is an important skill in the processing. In this paper, based on the convolution and Fourier's transformations theorems, the analytical models of predictive cutting forces which separate the forces into plowing and shearing effect, first harmonic force and identifying specific cutting force coefficients in micro ball end milling are developed by utilizing Fourier’s chip thickness with dimensionless. After the dynamometer has been used for a long time, unstable voltage or leakage of electricity is the cause of shifting of measured signal that will affect the accuracy of specific cutting force coefficients. The proposal is an identifying model for phase angle of measured cutting force because the magnitude of the first harmonic force will not be affected in measuring force signal. It can be used to compensate for the phase angle of the first harmonic force. Finally, the proposed analytical cutting force prediction model is validated exactly through conducting some micro ball end milling tests in a meso-scale micro milling machine tool.
23
Chen, Yi-Sung, and 陳逸松. "Application of Wavelet Analysis to Detection of Tool Wear in Ball-End Milling Operation." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/10613199999327225342.
Full textAbstract:
碩士<br>大同大學<br>機械工程研究所<br>88<br>Tool wear has long been identified as the most undesirable characteristic of the machining operations. Tool wear directly affects the workpiece dimensions and the surface quality. A reliable and sensitive technique for monitoring the tool wear without interrupting the process, is crucial in realization of the modern manufacturing concepts like unmanned machining centers, adaptive control optimization, etc. In this study milling force signals are used in conjunction with a wavelet theory for detection of tool wear on the ball-end mill cutter. The result of wavelet analysis of milling force signal compared the value calculated using the dynamic milling force model under sharp tool condition is to detect tool wear. The values predicted using the wavelet analysis are compared with the actual values using a tool maker’s microscope.
24
LIAO, YI-TING, and 廖翊婷. "The analysis of cutting the side wall of the ball end milling cutter stability analysis." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/82829414327168411027.
Full textAbstract:
碩士<br>建國科技大學<br>機械工程系暨製造科技研究所<br>103<br>The study of applied to the Software of Cutpro bringed the stability lobe in setting, many machining parameters will affect graphics generation. For example, cutting width, cutting depth each blade feed rate and cutting mode of arc remainder and vertical remainder. This study, probing into A6061 aluminum alloy and selecting different rudimental shape processing by sphere knife to bring stability lobe is available or not. Where the processing steady range when causing trembled? Therefore, using an arc rudimental shape model to the actual processing and measurement and observing its performance situation.
The results showed that an arc rudimental shape milling on the surface quality perspective, poor performance about 3400 rpm, 4680 rpm, 8900 rpm, 5900 rpm and 3680 rpm. Because trembled generated the shake trace on surface. Wherein surface quality the 5900 rpm along the feed direction of machining length increased with trembled. Right angle rudimental milling doesn’t cause trembled in most rotating speed. In fact of the results were the same with survey and evaluated of stability lobes: Processing smooth surface and no shake trace.
25
Hsu, Chia-Chi, and 許家旗. "An Intelligent System for Detection and Compensation of Tool Wear in Ball-End Milling Operations." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/74189111774170655745.
Full textAbstract:
碩士<br>大同大學<br>機械工程研究所<br>90<br>ABSTRACT
The tool wearing is considered as not hoped to acquired characteristics during manufacturing process, because it would directly affect the dimensions of work-piece and precision of cutting surface. In other hand, the detecting tool wearing from data acquired during on-line manufacturing condition is necessary characteristic for auto-manufacture.
Both fast analysis of the signal and efficiently distinguish wear from wavelet analysis is important to feedback the signal for patching cutting path during auto-manufacture. Generally, tool wearing would accompany with the variation of the dynamic cutting force. So using a 3-Component dynamometer to measure signals of dynamic cutting force and analyzing the signals to solve the relations of frequency variation between cutting force and tool wearing by wavelet theory analysis will process. Then using Adaptive Resonance Theory (ART- one type of self-learning neural networks) for tool wearing recognition and classification of signals. Above all, wavelet analysis combines with neural networks supply the function that detecting tool wearing and modify the cutting path from feedback signal of ART for compensation without supervising is properly.
26
Hsu, Chang-Yin, and 許彰印. "The Analysis of Statistical Model of Surface Roughness in Ball- End Milling Under High-Feed." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/37291638203462032654.
Full textAbstract:
碩士<br>大同工學院<br>機械工程學系<br>85<br>In the process of machining free-form surfaces, the surfaces
are often sculptured by a three-axis CNC machine with a
ball-end mill cutter. After machining, improvement on the
surface roughness becomes a considerable important
problem because the surface roughness affects the performance
and appearance of the products. In this study, experimental
factors, including cutting speed, feed, axial depth of
cut, inclination of specimen and tool radius, are taken into
consideration to investigate the effects of on the surface
roughness. To do this, the experimental design is adopted to
model the relationship between cutting conditions and surface
roughness. In the experimental design, the matrix is
planed by means of Response Surface Methodology and
Taguchi Method. The results associated with the
analysis of the variance can be practiced to assess the
prominence among experimental factors. The analysis
indicates that cutting speed, feed and tool radius play
significant factors on surface roughness. The results of
the regression analysis using a statistical software can be
applied to model the mathematical relationship between
machining factors and surface roughness. It
anticipates that the model is able to predict surface
roughness over a wide variety of cutting conditions. The model
is also proved in good agreement with experimental
results. Finally, an optimum method is adopted to search
the optimal cutting conditions with a better surface
quality under a wide variety of the tool radii and inclinations
of the specimen.
27
Xu, Zhang-Yin, and 許彰印. "The Analysis of Statistical Model of Surface Roughness in Ball- End Milling Under High-Feed." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/20781727357999115606.
Full text
28
Dai, Jing Zhi, and 戴兢志. "A mechanistic model for the prediction of the force system in ball-end milling operations." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/46040213952549122139.
Full text
29
Wu, Ping-Fang, and 吳秉芳. "An analytical Model of Milling Force in Ball-end Milling with Runout and Its Application to On-Line Identification of Cutter Runou." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/v5n2s4.
Full textAbstract:
碩士<br>國立成功大學<br>機械工程學系碩博士班<br>90<br>Abstract
This thesis presents an analytical model for the chip load variation and milling forces in ball-end milling with cutter runout. The cutting region and chip load variation is first discussed and an analytical expression for the chip thickness is discussed in this paper. Based on the chip thickness expression, the force model of ball-end milling with cutter runout is established. The force model shows the that the presence of cutter runout causes a significant change in the cutting force at the spindle frequency. The variation of milling force is shown to vary with the change of runout geometry, the runout magnitude, r, and the angular position, l.
Method for identification of cutting costants and runout geometry are presented. Two methods are presented to identify these cutting constans. The first method uses only the first harmonic components of the milling forces, and the second methods utilizes the average forces with two feeds per tooth. Based on the identified cutting constants, the identification of runout geometry is developed by using runout component cutting forces. Finally,the milling force model and the identification of runout geometry is verified through milling experiments.
30
Wei-Kai, Wang, and 王威凱. "The Analytic Prediction Model of Tool Life and Optimal Process Parameters in Micro Ball End Milling." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/75414538000494414934.
Full textAbstract:
碩士<br>國立高雄應用科技大學<br>機械與精密工程研究所<br>99<br>Micro milling is one of micro manufacturing with high processing efficiency, good machining accuracy and surface roughness, it’s can also machining high aspect ratio workpiece and reach into cavities, the depth of the processing can be much higher than other machining technology, while processing a wider range, and can complete the more complex 3D surface machining, and less restricted machining materials, with the potential for mass production. As the ball-end milling as special geometry, so the ball-end milling tool in the processing of surface roughness better than when using the end milling of the curved surface, so the ball-end milling are widely used in processing the surface geometry of the curved surface complex, such as mold, spiral blades, aviation components, etc., so developed as cutting conditions affect on the size accuracy and surface roughness, has its importance and usefulness.
Purpose of this research paper is the process planning and process parameters optimization to improve the milling quality and reduce manufacturing costs. To obtain the micro-end milling force by the milling force prediction model, and applied to the tool deflection analytical by milling force to obtain the process surface error. And the establishment of analytical milling force model in micro ball-end milling to obtain the cutting force coefficients, observed the change of cutting force coefficients of utilize online way, to determine the tool life, tool wear or need replacement ... etc. It’s saving a lot of time than removing tool to measure and loading up, relatively cost down. Designed the optimization process parameters for the different types of milling, cutting tool costs, feed rate, metal removal and spindle speed, and added the stiffness of machine tools, tool holder, cutting tools and workpiece (References[31] in the above conditions have been included in the model), establish a set optimization process parameters of micro-milling.
31
Chang, Tzi-Chiang, and 張自強. "A Flexible Mechanistic Model for the Prediction of the Force System in Ball-End Milling Operations." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/43956868191226822606.
Full textAbstract:
碩士<br>大同工學院<br>機械工程學系<br>85<br>This paper presents the development of a predictive model for
the force system in ball-end milling. The cutter used in the
design and analysis is an elliptic type ball-end mill. An
enhanced model for the prediction of cutting forces in ball-end
milling in a flexible sense has been developed.The force model
is essentially derived from metal cutting theory and for
thegeometric relations of the ball-end milling process. A
concise method forcharacterizing the complex geometry of an
elliptic ball-end mill is first determined. This method of
generation not only simplifies the descriptionof the geometry of
the cutting edge, but also provides the basis of
thedetermination of all geometric parameters to an accuracy
commensuratewith that needed for the oblique cutting process.
It is of primary importancethat the developed force model takes
into account the effects of system(tool and workpiece)
deflections on the chip load, and then solves for the chipload
that balances the cutting forces and the resulting system
deflections. Finally, by using AIM, design parameters of the
tool geometry associatedwith the developed force model is
utilize to analyze and determine theoptimum tool geometry of the
elliptic type ball-end mill for the best cuttingperformance. As
a result, the cutting forces of a 20mm-diameter ellipticball-end
mill are approach to minimum when semi-minor axis equals to
0.9*semi-major axis, and helix angle, rake angle have the values
of 32.5°, 6.5°, respectively.