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1
Ghosh, Swatilekha. "Electrodeposition of Cu, Sn and Cu-Sn alloy from choline chloride ionic liquid." Thesis, University of Newcastle upon Tyne, 2013. http://hdl.handle.net/10443/2279.
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Copper, tin and their alloy deposits are popular for its various applications in industrial aspects like enhance corrosion resistance and provide decorative finish. This work concentrated on the fabrication of these coatings, accomplished by electrodeposition technique which allows the control of thickness and microstructure of the films. Previously these metals and alloy were electrodeposited from different aqueous electrolytes. However these baths suffer from various environmental issues and deposits suffers from H evolution and metal oxide formation. As a result solution 2 ionic liquid (IL) was proposed as an alternative. ILs are categorized as salts liquid at room temperature and consist only of cations and anions. Presently Choline chloride based IL was used due to its advantages of low cost, low melting point, low toxicity, low viscosity and high conductivity than other ILs. Physical properties of the ILs like density, viscosity and conductivity were measured with variation of temperature and concentration of added metallic salts. To determine the electrochemical properties of individual metals and alloy, voltammetry scans were carried out using various scan rates and agitation rates. For all these measurements the concentration of Cu and Sn were varied in a range of 0.01 to 0.2 M and 0.01 to 0.1 M respectively at temperature range of 25 to 55 °C using a platinum rotating disk electrode (RDE). Deposition experiments were then carried out under potentiostatic and galvanostatic conditions using a stainless steel RDE. Material properties of the deposits like crystalline structure, grain size, strain, deposit morphology and chemical composition were analyzed using x-ray diffraction (XRD), optical microscope and scanning electron microscopy (SEM). The measurement showed that density and viscosity decreases and conductivity increases with rise in operation temperature for the electrolyte with and without metal ions. The reduction of both the metal was found to be mass transfer control and limiting current for metal deposition was found. The diffusion co-efficient -7 2 -7 2 obtained for Cu and Sn in the IL system was 1.22x10 cm /s and 1.96x10 cm /s -3 respectively. For individual metal Cu and Sn, best deposits were obtained at 4.7x10 2 -3 2 A/cm and 1.6x10 A/cm respectively using RDE speed of 700 rpm at 25 °C. The Cu deposit showed face centered cubic structure of 66±10 nm grain size and that of Sn was 62±10 nm with tetragonal crystalline structure. The smooth and bright Cu-Sn alloy deposit was obtained by applying potential in the range of 0.35 to 0.36 V vs. Ag wire or -3 2 0.8 to 0.9x10 A/cm of RDE speed is 220 rpm at 25 °C. The obtained deposits showed orthorhombic CuSn structure with a grain size of 21±10 nm. On annealing the 3 crystalline structure changed to hexagonal CuSn structure and the crystalline size 103 was obtained as 77±50 nm.
2
Caris, Joshua. "Heat Treatment Effects on Mechanical Behavior of Cu-15Ni-8Sn Produced via Powder Metallurgy." Case Western Reserve University School of Graduate Studies / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=case1184360740.
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Cooper, Shellene. "Creep behaviour of the ternary lead-free solder alloy, Sn-3.8wt.%Ag-0.7wt.%Cu." Thesis, Open University, 2002. http://oro.open.ac.uk/54417/.
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Electronic equipment is facing the challenge of both miniaturisation and the need to replace lead in interconnections. In service, interconnections generally fail by thermomechanical fatigue, and this behaviour is strongly affected by the creep process. This thesis examines the creep behaviour of a popular lead-free replacement alloy, Sn-3.8wt.%Ag-0.7wt%Cu (Sn-Ag-Cu), in joint and bulk form. Experimental work involved the determination of the creep properties of this alloy at various temperatures, over a range of stresses. Over the regions tested, the creep behaviour is best described by the Norton power law constitutive equation. The stress exponent for bulk Sn-Ag-Cu ranged between 10 and 18 (at 125 to -lOoC respectively) and indicates that a dispersion-strengthened mechanism is dominant in the creep process. The activation energy for creep in the bulk Sn-Ag-Cu is approximately 120kJ/moi and falls in the region similar to that observed for the self-diffusion of tin. In joint form the stress exponent is greater than 10 at high stresses but a change in mechanism is indicated at lower stress where the creep exponent falls to 3. The activation energy for creep in Sn-Ag-Cu when used in joint form is approximately 70kJ/moi and falls in the region similar to that observed for the short-circuit diffusion of tin. Results obtained from the ternary alloy were directly compared to those from Sn- 37wt.%Pb (Sn-Pb) and other prospective lead-free alloys in bulk form. The creep resistance of the ternary lead-free alloy at 75°C is superior to the conventional Sn-Pb alloy and the possible replacement alloys (tin-copper and tin-silver). This superiority is retained when tested at similar homologous temperatures. However, the Sn-3.8Ag- O.7Cu alloy is less ductile but generally possesses strains to failure above 10 percent in comparison to the 25 to 50 percent ductility of Sn-Pb.
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Horsley, Robert Michael. "Microstructural characterisation of solder joints using the Sn-Ag-Cu eutectic alloy in a no-clean surface mount technology (SMT) assembly process." Thesis, University of Salford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272696.
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Benedict, Michael Scott. "Heterogeneous nucleation of Sn in Sn-Ag-Cu solder joints." Diss., Online access via UMI:, 2007.
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6
Yassin, Amal M. "Creep microstructure relationships in Sn-Sb and Sn-Sb-Cu alloys." Thesis, Heriot-Watt University, 1999. http://hdl.handle.net/10399/1182.
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Pewnim, Naray. "Electrodeposition of Cu-Sn alloys from methanesulfonate electrolytes." Thesis, University of Newcastle Upon Tyne, 2012. http://hdl.handle.net/10443/1790.
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The most commonly used alloy in the electronics industry has been the ubiquitous tinlead alloy. As the demand for electronic devices continues to increase, there have been concerns about the continued use of lead and its long term environmental impact. In the last decade there has been a push to ban the use of lead in electronic products. Legislation from various governments around the world limiting the use of lead has given rise to the drive to find suitable lead-free alternatives. The aim of this research project was to establish a systematic approach for the selection of electrochemical parameters for the electrodeposition of tin-rich copper-tin alloys from a single electroplating bath. By studying and understanding a model system such as copper-tin, one can then use the information obtained as a basis to successfully deposit various other tin binary alloys in the future. Tin-rich deposits were enabled by employing various strategies such as maintaining a high Sn to Cu ratio in the electrolyte and by using surface active agents that have been known to facilitate alloy co-deposition. The effect of surfactants on the tin content in the deposit was initially examined with the aid of a rotating cylinder Hull cell. It was found that the presence of fluorosurfactant was crucial in eliminating metal oxide formation. Cyclic voltammetry at a rotating disk electrode showed that inclusion of surfactant in the electrolyte had no effect on the reduction potential of tin which remained at -0.45 V vs SCE. However, the reduction potential for copper shifted from approximately -0.13 to -0.18 V vs SCE, thereby facilitating alloy co-deposition. Chronoamperometry and anodic stripping voltammetry showed that current efficiency for copper-tin deposition ranged from 55-92% depending on the deposition time and deposit composition. Results from voltammetry experiments were used in the next galvanostatic electrodeposition experiments at vitreous carbon electrodes. Deposits containing up to 96 wt.% tin were obtained from both direct current and pulse plating modes. It was found that an optimal current density of 22 mA cm-2 was needed to obtain desirable deposits. For pulse plating the peak current density should be set to 100 mA cm-2 with a duty cycle of 0.2. Cu-Sn alloys obtained consisted of two phases, tetragonal tin and a hexagonal Cu6Sn5 intermetallic compound. Deposit annealing showed that the Cu3Sn intermetallic was not formed.
8
Kent, Damon. "Age hardening of sintered Al-Cu-Mg-Si-Sn alloys /." St. Lucia, Qld, 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17893.pdf.
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ISHII, HENRIQUE A. "Elaboracao de ligas Ag-Sn-Cu para amalgama dentario por moagem de alta energia." reponame:Repositório Institucional do IPEN, 2003. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11101.
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Picincu, Lucica. "The electrodeposition of Cu-Zn-Sn alloys from alkaline cyanide solutions." Thesis, University of Southampton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310845.
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Athavale, Saurabh. "Effect of Cu concentration and cooling rate on microstructure of Sn-3.9Ag-XCu." Diss., Online access via UMI:, 2006.
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Kotadia, Hirenkumar R. "Solidification behaviour of Al-Sn-Cu immiscible alloys and Al-Si cast alloys processed under intensive shearing." Thesis, Brunel University, 2010. http://bura.brunel.ac.uk/handle/2438/4517.
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Alloy castings are usually solidified with a coarse columnar grain structure under normal casting conditions unless the mode of the solidification is carefully controlled. It is desirable for the grain structure to be fine and equiaxed to improve their mechanical performance as finished castings. It is possible to develop a fine and equiaxed grain structure either by increasing the number of nucleation sites or by grain multiplication. Immiscible alloys with a microstructure in which a soft phase is dispersed homogeneously in a hard matrix have significant potential applications in advanced bearing systems, especially for the automotive industry. Despite considerable efforts made worldwide, including extensive space experiments, no casting techniques so far can produce the desired immiscible microstructure of alloys. Experimental results on Al-Sn-Cu immiscible alloys have confirmed that intensive shearing using melt conditioning by an advanced shearing technology (MCAST) unit, is an effective way to achieve a fine and uniform dispersion of the soft phase without macro-demixing, and that such a dispersed microstructure can be further refined in alloys with precipitation of the primary Al phase prior to the demixing reaction. In addition, it was found that melt shearing at 200 rpm for 60 s will be adequate to produce a fine and uniform dispersion of the Sn phase, and that a higher shearing speed and prolonged shearing time can only achieve further minor refinement. A study of Al-Si hypoeutectic and hypereutectic alloys presents the effects of the processing temperature and intensive shearing on the microstructural and mechanical properties which have been investigated systematically. Attempts have been made to explain the solidification mechanism with intensive melt shearing. The sheared melt was cast into tensile test samples by high pressure die caster (HPDC) to examine the microstructures and mechanical properties. The experimental results reveal that significant grain refinement and uniformity of grains was achieved by the intensive shearing and also a considerable increase in mechanical properties with pouring temperature by changing intermetallic particles morphology, the position of defect band and reduced microscopic defects.
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SILVA, LUIS C. E. da. "Estudos do desenvolvimento e caracterização das ligas Cu-Ni-Pt e Cu-Ni-Sn para fins eletro-eletrônicos." reponame:Repositório Institucional do IPEN, 2006. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11480.
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Martorano, Marcelo de Aquino. "Efeitos de algumas variáveis de processo na microssegregação da liga Cu-8%Sn." Universidade de São Paulo, 1998. http://www.teses.usp.br/teses/disponiveis/3/3133/tde-23082017-073753/.
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Os processos de fundição que visam à obtenção de produtos fundidos com formatos e propriedades mais próximos dos necessários ao produto final demandam um conhecimento detalhado das relações entre processo e microestrutura e entre microestrutura e propriedades. Não há dúvida de que aspectos microestruturais como o tamanho, a morfologia e o nível de microssegregação da estrutura dendrítica são importantes em definir as suas propriedades. Por outro lado, as variáveis de processo que afetam a transferência de calor no sistema estão entre as mais importantes em definir as características de microestrutura bruta de fundição. O presente trabalho tem como objetivo principal estudar os efeitos de algumas variáveis do processo de fundição na microssegregação de ligas fundidas em moldes metálicos. Para este fim, escolheu-se a liga Cu-8%Sn, que foi obtida na forma de amostras solidificadas unidirecionalmente. Os efeitos de diferentes sistemas de extração de calor, diferentes temperaturas de vazamento e da adição de inoculante foram investigados. Dois tipos de sistema de extração de calor foram empregados, um utilizando uma base de cobre refrigerada a água, outro uma base maciça de cobre revestida superficialmente com uma tinta isolante térmica. As temperaturas de vazamento escolhidas foram \'1110 GRAUS\'C e \'1270 GRAUS\'C e o inoculante adicionado foi a liga Cu-50%Zr. Modelos matemáticos para a transferência de calor e massa no sistema foram desenvolvidos para auxiliarem noentendimento dos fenômenos importantes envolvidos na solidificação das amostras. As temperaturas em diversos pontos do metal foram medidas durante a sua solidificação através de um sistema digital de coleta de dados. Os resultados foram utilizados para o cálculo de diversos parâmetros, como o coeficiente de transferência de calor entre o metal e a base de cobre. O nível de microssegregação das amostras foi calculado a partir de microanálises conduzidas ) através de uma microssonda acoplada a um microscópio eletrônico de varredura. Imagens de microscopia ótica e de varredura auxiliaram nas medidas de espaçamento entre braços de dendrita e na interpretação da morfologia dendrítica. A partir dos resultados, observou-se que é possível modelar matematicamente a transferência de calor no sistema sem a consideração detalhada de efeitos macro e microestruturais. Notou-se, também, que há um decréscimo no nível de microssegregação próximo à superfície das amostras, efeito este que só pode ser modelado matematicamente quando as curvas experimentais de temperatura durante a solidificação forem conhecidas. Verificou-se que a estrutura colunar apresentou um menor nível de microssegregação do que a estrutura equiaxial, o que parece estar relacionado com a maior facilidade de homogeneização da estrutura colunar durante a solidificação<br>Casting processes which aim at products of near-net-shape and near-net-properties need a detailed konwledge of the relationship between processing variables and microstructure, and between microstructure and properties. It is well known that microstructural features, such as dendrite size, morphology and microsegregation severity have a tremendous effect on casting product properties. In addition to it, the processing variables on which heat transfer in the system depends arise as the most important ones ti define the characteristics of as-cast microstructures. The main objective of this work is to study the effects of some processing variables on the microsegregation of permanent mould cast alloys. Directionally solidified samples of a Cu-8%Sn alloy were chosen to be studied, and the effects of inoculation, different heat extraction devices and different pouring temperatures were investigated. The pouring temperatures were 1110 ºC and 1270 ºC, and a CU-50%Zr alloy was added for inoculation. Mathematical models of heat and mass transfer for the system were developed to help understand the important phenomena underlying the solidification of the samples. During solidification, temperatures were measured at some points within the samples by means of thermocouples connected to a data acquisition system. The measured temperatures were used to calculate some parameters, such as the heat transfer coefficient between the alloy and a copper chill. Severity of microsegregation was assessed through microanalysis carried out with the microprobe of a scanning electron microscope. Dendrite arm spacing measurements and the examination of dendrite morphology were on optical and scanning electron microscope images. Results have shown that proper mathematical models of heat transfer does not need to account for detailed effects of macro and microstructural features. Severity of microsegregation was noticed to decrease along samples, towards their surfaces. This trend cannot be modelled unless temperature measurements during solidification are provided. Columnar dendrites have shown less microsegregation than equiaxed ones, which seems likely to be effects of a higher homogenization degree of the columnar structures .
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Silva, Luis Carlos Elias da. ""Estudos do desenvolvimento e caracterização das ligas Cu-Ni-Pt e Cu-Ni-Sn para fins eletro-eletrônicos"." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-31052007-153314/.
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O Cu e suas ligas têm diferentes aplicações na sociedade moderna devido as excelentes propriedades elétricas, condutividade térmica, resistência à corrosão dentre outras propriedades. Estas aplicações podem ser em válvulas, tubulações, panelas para absorção de energia solar, radiadores para automóveis, condutores de corrente e eletrônico, elementos de termostatos e partes estruturais de reatores nucleares, como, por exemplo, bobinas para campo toroidal para um reator de fusão nuclear. Dentre as ligas utilizadas em reatores nucleares, podemos destacar Cu-Be, Cu-Sn e Cu-Pt. O Ni e o Co, freqüentemente são adicionados às ligas de Cu para que a solubilidade seja deslocada para temperaturas mais elevadas com relação aos sistemas binários de Cu-Sn e Cu-Pt. A adição de Ni-Pt ou Ni-Sn ao Cu em porcentagens iguais ou inferiores a 1,5 % aliado a tratamentos termos-mecânico alteram as propriedades do Cu. Estudamos neste trabalho sete diferentes ligas: três ligas de Cu-Ni-Pt 1 (97,99 % Cu - 1,55 % Ni - 0,46 % Pt), 2 (99,33 % Cu - 0,23 % Ni -0,43 % Pt) 3 (98,01 % Cu - 0,48 % Ni - 1,51 % Pt); três ligas de Cu-Ni-Sn 4 (98,31% Cu - 1,12 % Ni - 0,58 % Sn), 5 (98,79 % Cu 0,57 % Ni - 0,65 % Sn), 6 (98,39% Cu 0,46 % Ni 1,16 % Sn) e Cu eletrolítico 0 (0,0058 % Pb - 0,0007 % Fe - 0,0036 % Ni - 0,0024 % Ag). As referentes ligas foram desenvolvidas a partir de um forno a arco voltaico e passaram por tratamentos termo-mecânicos pré-determinados. As microestruturas foram analisadas diretamente por microscopia óptica e microscopia eletrônica de varredura / EDS e indiretamente por medidas de dureza Vickers e condutividade elétrica. O objetivo deste trabalho, portanto, foi observar e constatar os efeitos da mudança da microestrutura em relação às propriedades dureza e condutividade elétrica.<br>The Cu and its alloys have different applications in the owed modern society the excellent electric properties, thermal conductivity, resistance to the corrosion and other properties. These applications can be in valves, pipes, pots for absorption of solar energy, radiators for automobiles, current driver, electronic driver, thermostats elements and structural parts of nuclear reactors, as, for example, reels for field toroidal for a reactor of nuclear coalition. The alloys used in nuclear reactors, we can highlight Cu-Be, Cu-Sn and Cu-Pt. Ni and Co frequently are added to the Cu alloys so that the solubility is moved for temperatures more elevated with relationship to the binary systems of Cu-Sn and Cu-Pt. The addition of Ni-Pt or Ni-Sn to the Cu in the same or inferior percentages to 1,5% plus thermomechanical treatments changes the properties of the copper. We studied the electric conductivity and hardness Vickers of the Cu-Ni-Pt and Cu-Ni-Sn and compared with the electrolytic Cu. In the proposed flowcharts, breaking of the obtaining of the ingot, we proceeded with thermo mechanical treatments.
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Wederni, Asma. "Synthèse, caractérisation et étude magnétique des alliages à mémoire de forme de type Heusler Ni-Mn-Sn-X (X= Pd, Cu)." Doctoral thesis, Universitat de Girona, 2021. http://hdl.handle.net/10803/673935.
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Shape memory alloys witch exhibit magnetically induced phase transformations at room temperatures are the most interesting for magnetic cooling applications. Heusler type alloys (both stoichiometric and non-stoichiometric) are among the most studied systems, as they permit the change of the transition temperatures due to compositional variations. The first Heusler alloys that have been studied in depth are Ni- Mn-Ga alloys. However, to overcome the high cost of Gallium and low martensitic transformation temperature, the search for Ga-free alloys has been recently endeavoured, principally, by introducing In, Sn or Sb.
The purpose of this work is the production and characterization of non-stoichiometric Heusler alloys based on a Ni-Mn-Sn composition, with copper or Palladium doping. The effect of doping element will be determined, on the crystalline structure, the phase transition temperatures, the thermodynamic and magnetocaloric parameters. On the other hand, a heat treatment will be exerted on Ni-Mn-Sn-Cu alloys then characterize them in the same way. Shape memory alloys will be produced in the first step, by arc melting technique, to produce the bulk and then by melt spinning, to obtain shape memory ribbons. Produced samples are characterized by scanning electron microscopy (SEM) technique, to check the morphological structure of the alloys, microanalysis technique (EDX) to have the final composition experimentally, X-ray diffraction technique (XRD) to extract information from the crystal structure, differential scanning calorimetry (DSC) to study the thermal and thermodynamic variations induced by structural phase transformations and finally magnetometry techniques (Physical property measurement system, PPMS: VSM, resistivity, hysteresis cycles) to characterize the phase transformations behaviour and magnetocaloric effect under applied external magnetic fields.
Among the results obtained in the present work it can be concluded that both Cu-doped and Pd-doped alloys have similar morphology. The reversible austenite-martensite transformation was detected in all ribbons. Cu or Pd doping tends to increase the structural transition temperatures. These changes in the magnetic and martensitic transformation temperatures are confirmed report directly to the ratio (e/a) of the alloy. Moreover, it’s emphasized the fact that Pd doped alloys show a good magnetocaloric effect (the maximum variation of ΔS is approximately 4.5 J / (Kg.K) for an applied magnetic field of 50 kOe and the refrigeration capacity is 28 J / kg). This dependence must allow the selection of the appropriate composition for the production of alloys with transformation into a desired temperature range. On the other hand, measurements of DRX, DSC and magnometry carried out on Ni-Mn-Sn-Cu alloys after application of thermal cycles of heating-cooling of 100 times, allowed us to certify the great stability of the alloys and the shape memory effect (minor change in phase transformation temperatures and curie temperatures)<br>Els aliatges tipus Heusler (tant estequiomètrics com no estequiomètrics) es troben entre els sistemes més estudiats, ja que permeten el canvi de les temperatures de transició a causa de les variacions de la composició. Els primers aliatges de Heusler que s’han estudiat en profunditat són els aliatges de Ni-Mn-Ga. No obstant això, per superar l’elevat cost del gal i la baixa temperatura de transformació martensítica, recentment s’ha intentat buscar aliatges sense Ga, principalment, introduint In, Sn o Sb.
L’objectiu d’aquest treball és la producció i caracterització d’aliatges de Heusler no estequiomètrics a partir d’una composició de Ni-Mn-Sn, amb dopatge de cobalt o pal·ladi. L'efecte de l'element dopant es determinarà, sobre l'estructura cristal·lina, les temperatures de transició de fase, els paràmetres termodinàmics i magnetocalòrics. D’altra banda, s’exercirà un tractament tèrmic sobre els aliatges de Ni-Mn-Sn-Cu per després caracteritzar-los de la mateixa manera. Els aliatges de memòria de forma es produiran en el primer pas, mitjançant la tècnica de la fusió de l’arc, per produir l’aliatge massiu i després per la fusió per obtenir cintes de memòria de forma.
Les mostres produïdes es caracteritzen per la tècnica de microscòpia electrònica d’escombratge (SEM), per comprovar l’estructura morfològica dels aliatges, la tècnica de microanàlisi (EDX) per tenir la composició final de manera experimental, la tècnica de difracció de raigs X (XRD) per extreure informació de l’estructura cristal·lina, calorimetria d’escaneig diferencial (DSC) per estudiar les variacions tèrmiques i termodinàmiques induïdes per transformacions de fase estructurals i finalment tècniques de magnetometria (PPMS: VSM, resistivitat, cicles d’histèresi) per caracteritzar el comportament de les transformacions de fase i l’efecte magnetocalòric sota camps magnètics externs aplicats.
Entre els resultats obtinguts en el present treball es pot concloure que tant els aliatges dopats amb Cu com els aliatges dopats amb Pd tenen una morfologia similar. La transformació reversible d'austenita-martensita es va detectar a totes les cintes. El dopatge Cu o Pd tendeix a augmentar les temperatures de transició estructural. Aquests canvis en les temperatures de transformació magnètica i martensítica es confirmen directament a la relació (e / a) de l'aliatge. A més, s’ha destacat el fet que els aliatges dopats amb Pd mostren un bon efecte magnetocalòric. Aquesta dependència ha de permetre seleccionar la composició adequada per a la producció d'aliatges amb transformació en un rang de temperatura desitjat. D’altra banda, les mesures de DRX, DSC i magnometria realitzades sobre aliatges Ni-Mn-Sn-Cu després de l’aplicació de cicles tèrmics de calefacció-refrigeració de 100 vegades, ens van permetre certificar la gran estabilitat dels aliatges i la efecte memòria de forma<br>Programa de Doctorat en Tecnologia
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Hunter, Elizabeth Adele Outdoor. "The Smallest Base and Precious Metal Deposits in the World: Vapor Transport and deposition of Co-Cu-Sn-Ag alloys in vesicles." BYU ScholarsArchive, 2007. https://scholarsarchive.byu.edu/etd/1406.
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Metallic bronze-Co-Ag alloys ranging from1-90 µm have been discovered in bomb and lava vesicles from the mafic volcanoes of Kilauea in Hawaii and Vesuvius, Stromboli and Etna in Italy. It is inferred that the metals for these alloys were transported (in part) as chloride complexes, and that the metal ratios in the alloys may be a function of S/Cl. Alloy compositions in each system are extremely heterogeneous with Co concentrations from 1% to 94%, Cu from 2% to 89%, Sn from 1% to 22% and Ag from 0.5% to 42%. Maximum abundances (in wt%) of other trace or minor elements are, Fe (3.0), Zn (0.11), As (0.50), Pd (0.05), Pt (0.05), Au (0.05), Hg (0.10) and Pb (.13) Spot analyses and element maps of alloy grains reveal that three major exsolved components exist. They are bronze, Co, and Ag. Kilauean alloys are dominantly Cu-Sn (bronze) with little Co and Ag while a systematic decrease in the bronze component and an increase in Co occurs in grains from Stromboli to Etna to Vesuvius. Element maps show a covariance of Cu and Sn while Co and Ag concentrations vary independently. Element maps of the alloys also reveal that chlorides are occasionally present in the same vesicles as the alloys. Sulphur content of the metal alloys rarely exceed about 0.4 wt%. Electron back-scatter diffraction (EBSD) was employed for lattice characterization of the exsolved phases and shows a FCC structure for the Cu-Sn section of the alloys. Cu-Sn alloys high in Sn are successfully indexed using the Cu6Sn5 pattern (hexagonal), even though the Sn:Cu ratio of our alloys is considerably lower than 5:6. Cu-Sn alloys containing significant subequal amounts of Co and Fe (≈5 wt% each) indexes as body-centered cubic (BCC). The presence of alloys suggests metal transport as complexes in a vapor phase before being reduced to native metals. Our current model for the origin of the alloys suggests that the metals are transported to vesicles as chlorides and then deposited as sulfides and/or native metals. Oxidation and removal of most of the S then occurs. This data suggests that in some circumstances Cu-Sn-Co and Ag are readily partitioned into escaping magmatic volatiles during quenching of mafic magma. Further examination into vesicle-hosted alloys may confirm that the ratio of Cu, Ag, Au, Zn, and Pb in vesicles reflects the ratio of available metals present in the magma and in subsequent ore deposits.
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Zaher, Ghenwa. "Microstructure et comportement mécanique du cuivre et d'un alliage Cu-Sn nanostructurés par déformation plastique intense et implantés à l'azote." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMR031/document.
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Les alliages de cuivre sont utilisés dans de nombreuses applications électriques car ils offrent un bon compromis de résistance mécanique, de résistance à la corrosion et de conductivité électrique. Cependant pour certaines applications comme les contacteurs électriques, des matériaux plus performants sont recherchés. L’affinement de la taille de grains et l’implantation ionique sont deux voies que nous avons explorées dans ce but. Afin d’obtenir un bon compromis entre la dureté, la résistance à la corrosion et la conductivité électrique du cuivre pur (99,90%) et un bronze commercial monophasé contenant 8 % massique d’étain ont été nanostructurés par déformation plastique intense, et ensuite implantés à l’azote. Dans un premier temps, nous avons étudié l’évolution de la dureté des matériaux que nous avons corrélée aux changements microstructuraux induits par déformation plastique intense. Grâce à la microscopie électronique en transmission (MET) et la diffraction des rayons X (DRX), nous avons pu mettre en évidence la formation de grains ultrafins. Et nous avons prouvé que la solution solide CuSn métastable n’était pas décomposée au cours de la déformation. Par ailleurs, il a été montré que l’étain en solution solide favorise l’affinement des grains et que la déformation du CuSn8 à des vitesses plus rapides limite la restauration dynamique des défauts en engendrant une plus grande dureté. Un modèle qualitatif prenant en compte la production et l’annihilation de dislocations a été développé permettant de prédire l’influence des paramètres procès sur l’évolution de la microstructure et de la dureté. La stabilité thermique des nanostructures formées par déformation intense a également été étudiée, notamment par calorimétrie différentielle à balayage. Il a été montré que l’ajout d’étain en solution solide retarde la recristallisation alors que la densité de défauts et donc la force motrice est plus importante. Le Cu et le CuSn8 recristallisés et à grains ultrafins ont été implantés à l’azote. Il a été montré par nanoindentation que les duretés superficielles du Cu recristallisé et du Cu nanostructuré augmentent significativement après implantation. Nous avons mis en évidence par MET (SAED, STEM HAADF et EELS) la formation de nitrures de cuivre qui sont à l’origine du durcissement superficiel. Des nitrures de cuivre ont été également été formés dans le CuSn8 alors qu’aucun nitrure d’étain n’a été détecté. Par ailleurs, il est intéressant de noter que les défauts et notamment les mâcles formées après déformation intense semblent favoriser la diffusion de l’azote et être des sites de germination préférentielle des nitrures de cuivre<br>Copper is the most used material in electrical field applications. For electrical contacts, its oxidation behavior, thermal stability and hardness is essential. In this work, we attempted to find the key to make strong, but also conductive metal with a high corrosion resistance by finding an appropriate copper microstructure and surface treatment. It is well known that material properties are determined by their microstructure. Also, it was seen that nitride films enhance the oxidation resistance and the surface hardness. Therefore, to achieve our goal, pure copper and a bronze alloy Cu-8wt. %Sn have been subjected to high pressure torsion to make ultra-fine-grains and the surface was then implanted with nitrogen ions. We have investigated the effect of deformation on the hardness and the thermal stability by Vickers microhardness and DSC measurements. It is shown that tin in solid solution delay the recrystallization of the UFG produced by HPT. Tin also promotes the grain refinement and limit the dynamic annihilation during HPT deformation. Furthermore, a correlation between the properties and the microstructure was done by SEM and TEM analyses. A qualitative model taking into account the production and annihilation of dislocations has been developed to predict the influence of process parameters on the evolution of microstructure and hardness. Recrystallized and UFG Cu and CuSn8 were implanted with nitrogen. It has been shown by nanoindentation that their surface hardness increase significantly after implantation. TEM analyses (SAED, STEM HAADF and EELS) demonstrated the formation of copper nitrides which cause superficial hardening. Copper nitrides were also formed in CuSn8 whereas no tin nitride was detected. Moreover, it is interesting to note that the defects (in particular deformation twins) seem to be preferential nucleation sites for copper nitrides
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Holtmeier, Stefan. "Effets magnétovolumiques dans des composés à fermions lourds CeRu2Si2, CeCu6 et CeNiSn." Université Joseph Fourier (Grenoble), 1994. http://www.theses.fr/1994GRE10117.
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Ce memoire decrit des etudes de dilatation thermique et de magnetostriction effectuees au moyen d'un dilatometre capacitif sur des monocristaux de composes a fermions lourds, entre 0. 2 et 300 k et sous des champs magnetiques allant jusqu'a 11 t. Dans une premiere partie, sont decrits des resultats sur l'alliage ce#0#. #9#8#5y#0#. #0#1#5ru#2si#2, qui completent une etude precedente du compose ceru#2si#2 pur et de l'alliage ce#0#. #9#5la#0#. #0#5ru#2si#2. Leur energie caracteristique obeit a une loi d'echelle. Aucun des de ces trois composes ne presente d'ordre magnetique a longue distance, mais des correlations antiferromagnetiques a courte portee, lesquelles disparaissent lors d'une transition induite sous champ, qualifiee de pseudometamagnetique. Les effets d'alliage sur la dilatation volumique et sur la largeur de cette transition sont discutes, et une explication basee sur un effet kondo en presence des correlations est presentee. Le compose cecu#6 montre des effets magnetovolumiques tres anisotropes. A tres basse temperature, une faible transition pseudometamagnetique a pu etre detectee. Le comportement sous champ est discute en terme d'effet kondo a un site. La formation d'un gap semiconducteur dans cenisn n'a pas de forte influence sur les proprietes magnetovolumiques. Par contre, nos experiences confirment l'existence d'un pseudogap de spin tres anisotrope. Les modeles theoriques qui tentent d'expliquer ce comportement nouveau dans les semiconducteurs magnetiques sont discutes
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Wei, Cheng-Chang, and 魏程昶. "Electromigration Studies on Sn(Cu) and Sn(Ni) Alloy Stripes." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/60068197745363733474.
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碩士<br>國立中央大學<br>化學工程與材料工程研究所<br>92<br>By using Blech structure, we have studied the EM behaviors on four different Sn(Cu) and Sn(Ni) alloys, which are Sn, Sn0.7Cu, Sn3.0Cu, and Sn1.0Ni. The EM rates of above alloys were determined and the order of the magnitudes is: Sn0.7Cu > Sn > Sn3Cu > Sn1.0Ni. Sn0.7Cu shows the highest EM rate among three Sn(Cu) alloys. The possible reasons are that eutectic Sn0.7Cu has a high density of grain boundary and a low yielding strength. Knowing the EM fluxes of alloy stripes in different lengths, the critical lengths and the critical products were determined. The critical products for Sn, Sn0.7Cu, and Sn3.0Cu are 1500 amp/cm, 500 amp/cm, and 1580 amp/cm, respectively. In this study, DZ* of Sn(Cu) alloys were obtained. Since, the Sn diffusivity in the Sn matrix is known, Z* of pure Sn can be further calculated to be 97, which is slightly larger than the literature value, 80.
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Liu, Chia-Yu, and 劉家佑. "The Properties of Composite Solders of Sn-3.0 wt.% Ag- 0.5 wt.% Cu alloy Added with Sn-10.0 wt.% Cu alloy." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/2q7d46.
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Jindal, Nikhil. "Development of Lead Free sn-bi-cu Solder Alloy." Thesis, 2018. http://ethesis.nitrkl.ac.in/9575/1/2018_MT_216MM244_NJindal_Development.pdf.
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Until recently, lead-containing alloys were considered
to be the most suitable soldering materials widely applied in the automotive industry and in several other sectors.However,with the implementation of EU(European union) environmental directives, the use of such alloys has become prohibited for negative effect on health. In this work we have studied various eutectic system like Sn-8.8 wt.% Zn, Sn-3.5 wt. % Ag and Sn-57wt. %Bi and Sn-0.7 wt. % Cu to find best alternative of Sn-Pb solder alloy. The characterization of microstructure was done by optical as well as scanning electro nmicroscopy (SEM).The composition of the solder alloys were determined by using Energy Dispersive X-ray spectroscopy (EDX). Differential scanning calorimetry (DSC)was done to find out the melting temperature of the alloys. Phase analysis for the alloys was done using X-ray diffraction. Tensile test was performed to find out the mechanical properties of the alloys. The present work reports the effect of addition of Cu on the melting point, hardness and electrical resistivity of Sn-57 wt. % Bieutectic solder alloy. Both binary eutectic Sn-57wt. % Bi and ternary Sn-(57-x) Bi-xCu (x = 0.1, 0.3, 0.5, 0.7 and 1 wt. %) alloys containing various amounts of Cu were developed by melting casting route.The microstructure of the various solder alloys were analyzed using an optical microscope and a SEM. The variation in melting point, hardness and electrical resistivity of the Sn-Bi eutectic solder alloys with the addition of Cu was determined. The melting point of the eutectic Sn-Bi solder alloy was found to decrease upto the addition of 0.7 wt. % Cu. However, further addition of Cu led to an increase in the melting point of the alloy. Addition of Cu led to an increase in the hardness of the eutectic Sn-Bi solder alloy whereas the electrical resistivity of the eutectic Sn-Bi solder alloy was found to increase upto the addition of 0.7 wt. % of Cu beyond which a decrease in the electrical resistivity was observed.A change in the microstructure of the solder alloy was observed when it was reheated above the melting temperature.
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Phani, Akella Siva Durga. "A Comparative Study of the Sn-Ag, Sn-Zn, Sn-Cu, Sn-Bi Lead Free Solder Alloys with the Commercially Available Sn-Pb Solder Alloy." Thesis, 2016. http://ethesis.nitrkl.ac.in/8079/1/2016_M_Tech_711MM1132_A_Compararative_Study.pdf.
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As soldering controls the effective usage and processing of electronic components in applications and devices. Solders are used as interconnect materials in microelectronic packaging. Traditionally Pb-Sn eutectic alloys have been used due to its low melting point and good wettability. However, due to the toxic nature of lead (Pb) and it harmful effect on environment and health the usage of Pb in solder should be avoided. This is why there is a need to develop environmentally benign Pb-free solders (LFS).In this research work four different lead free solder alloys, Sn-Cu, Sn-Ag , Sn-Bi , Sn-Zn, and Sn-Pb are developed and characterized. Eutectic Sn-0.7 wt. % Cu, Sn-3.5 wt. % Ag, Sn-57 wt. % Bi, Sn-8.8 wt. % Zn and Sn-37 wt % Pb solder alloys have been developed by melting and casting route. A comparative study of all the five alloys was done based on their microstructure and various properties like electrical resistivity, hardness, fractography and wettability on Cu substrate. Their microstructure of the alloys was analyzed using optical microscopy and scanning electron microscopy (SEM). The various phases in the alloys were analyzed using energy dispersive x-ray spectroscopy (EDS) attached to the SEM. The nature of fracture in the alloys was analyzed using SEM. The melting point of the alloys was determined using differential scanning calorimeter (DSC). Hardness of the alloys was determined using a Vicker‟s microhard ness tester. The wettability of the solder alloys on Cu substrate was analyzed using SEM. Electrical resistivity of all the alloys were determined using a four point electrical probe. The objective of this study is to find out the solder alloy among the four eutectic solder alloys chosen here which could replace the traditional Sn-Pb solder alloy.
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Chen, Chun-Wei, and 陳駿維. "Interfacial reaction between Sn(Cu) solder and NiCo alloy UBM." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/49636679478494714528.
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碩士<br>國立中央大學<br>化學工程與材料工程研究所<br>97<br>In the work, we study soldering reaction between Ni-Co alloy layer and Sn(Cu) Pb-free solders. Different Co concentrations in Ni-Co alloy layer were electroplated on Cu foils. Then, Sn(Cu) solders were reflowed on the Ni-Co alloy layers at 250 ℃ to investigate the growth situation and morphology of IMCs and to discuss the effect of Co concentration and Cu concentration on the reaction between Sn(Cu) and Ni-Co layer.
Experimental results show that when the composition of NiCo alloy are Ni, Ni-20at%Co, Ni-63at%Co and Co, the corresponding IMCs formed at the interface are Ni3Sn4, (Ni,Co)Sn2, (Ni,Co)Sn3 and CoSn3. We also observe that the consumption of Ni-63at%Co alloy is more serious than other NiCo alloys and it is due to the loose structure of IMCs.
In the case of Ni-20at%Co, after 300 seconds reflowing additional needle-like phase (Ni,Cu)3Sn4 was formed right above the continuous (Ni,Co)Sn2 layer when Cu concentration overs 0.2wt% and Cu addition enhance the growth rate of (Ni,Co)Sn2. In the case of Ni-63at%Co and Co, as Cu addition and increasing of Cu concentration are performed only CoSn3 formed at the interface, but these factors restrain the growth rate of CoSn3.
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Wu, Hsiu-Hsien, and 吳修賢. "Sn-Ag-Cu Alloy Wire Formed by Fused Deposition Modeling." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/27128323794280842656.
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碩士<br>國立宜蘭大學<br>機械與機電工程學系碩士班<br>103<br>In recent years fused deposition modeling technology could be applied widely in biomedical engineering, aerospace engineering and automotive industry and so on, because of this technology has some of the advantages like easy to operation and clean process. However, thermoplastic is widely practiced in FDM process, cause of common metals and alloy’s melting point are over than FDM’s working temperature. This research presents the development of a low melting temperature metal alloys for use in fused deposition modeling (FDM) technology to make 3-dimensional structure and electrical connection.
In this study, the material consists of commercially available low melting temperature solder alloys (Sn-3.0Ag-0.5Cu, Sn-0.3Ag-0.7Cu) were tested for the building up a fused deposition modeling for metals and is divided into two parts. The first section is the demonstrate the ability of extrusion and deposition for electrical connection wire, which the extrude out the varying size extrusion nozzle(Ø0.4,Ø0.6,Ø0.8) with three kind of combinestion process parameters and deposition of eutectic Sn-3.0Ag-0.5Cu and non-eutectic Sn-0.3Ag-0.7Cu materials. The second section is the printed metallic specimens of dimensional accuracy, microstructure and composition, mechanical properties and electrical properties are investigated experimentally.
Results are as follows: The first section was presented which the ability of extrusion is not affected by eutectic effect. It is related to a nozzle size and process parameters. The second section is showed that the nozzle size and process parameters exert influence on dimensional accuracy. On condition that nozzle size Ø0.8, high printing speed and working temperature exists optimization of dimensional accuracy. When compared to eutectic Sn-3.0Ag-0.5Cu and non-eutectic Sn-0.3Ag-0.7Cu produced deposition results. The non-eutectic Sn-0.3Ag-0.7Cu alloy of deposition results is better than eutectic Sn-3.0Ag-0.5Cu alloy. Microstructure and composition is presented that microstructure appearance in Sn-3.0Ag-0.5Cu alloy and Sn-0.3Ag-0.7Cu alloy are not detective intermetallic compound(IMC), like Ag3Sn or Cu6Sn5, Only finds trace elements(Ag and Cu) penetrated and crowd to β-Sn base. With the increase of the working temperature, the concentration of Ag and Cu elements in β-Sn base comes to increase too. The microstructure appearance between alloy and Cu substrate are not detective Ag3Sn or Cu6Sn5 too, and increase of the working temperature cause of concentration of Cu elements increases. Compared with Sn-3.0Ag-0.5Cu alloy of printing specimens, concentration of Cu elements of Sn-0.3Ag-0.7Cu is not as much heavy. The mechanical properties is presented that Vickers microhardness in Sn-3.0Ag-0.5Cu alloy and Sn-0.3Ag-0.7Cu alloy of printing specimens improved somewhat compared as solder. Tensile strength is showed that as solder better than printing specimens. Peel test is presented that the printing specimens of Sn-3.0Ag-0.5Cu alloy’s adhesion force greater than Sn-0.3Ag-0.7Cu alloy. Part of electrical properties, the findings indicate that the electrical resistivity values of Sn-3.0Ag-0.5Cu alloy of printing specimens higher than Sn-0.3Ag-0.7Cu alloy’s.
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Li, Chia-Ying, and 李佳蔭. "Phase equilibria in the Sn-rich corner of the Sn-Cu-Ni ternary alloy system." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/49157458433148202389.
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碩士<br>國立清華大學<br>材料科學工程學系<br>92<br>The interfacial reactions between solders and under bump metallization (UBM) are of highly interests recently in flip chip technology. Intermetallic compounds (IMCs), i.e. (Cu,Ni)6Sn5 and (Ni,Cu)3Sn4, formed between solders and UBM. To fully understand the interfacial reactions and phase transformation phenomenon, a suitable phase diagram concerning solder, IMCs and UBM material is required. As a result, Sn-riched phase in Sn-Cu-Ni ternary phase diagram is very critical in determining the concentration tendency of x and y values in (Ni1-x,Cux)3Sn4 and (Cu1-y,Niy)6Sn5 compounds. In this study, ternary Sn-Cu-Ni alloys were prepared and annealed at 240℃. Three equilibrium phases, Sn, Ni3Sn4 and Cu6Sn5, were identified by XRD analysis, and also evidenced in BEI micrograph. Using EPMA quantitave analysis, three acme compositions of the ternary region in the Sn-Cu-Ni isotherm near the Sn-riched corner were determined as 98.5 at.%Sn, (Ni0.80, Cu0.20)3Sn4 and (Cu0.59,Ni0.41)6Sn5. Furthermore, the degree of composition homogeneity and the distribution of the forming phases were evaluated by X-ray color mapping and phase analysis technique. By way of software program to convert the concentration measured with EPMA, the exact compositions could be mapped on the Sn-Cu-Ni ternary isotherm. In addition, the solubility of the Cu and Ni in (Ni,Cu)3Sn4 and (Cu,Ni)6Sn5 compounds was evaluated. Finally, the isothermal section of the ternary Sn-Cu-Ni system at 240℃ was proposed on the basis of experimental results in this study. Furthermore, the related phase transformation was also discussed with respect to the formation of the IMCs around 240℃.
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HSU, PO-CHUN, та 許博淳. "Fabrication and properties characterization of Cu一Sn Alloy/HDPE composites". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/96511352161313628379.
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碩士<br>國立臺灣科技大學<br>高分子系<br>98<br>In this experiment, the conductivity properties of high density polyethylene (HDPE) composites filled with (Cu-Sn ) Alloy and modified Cu-Sn Alloy (MCu-Sn ) which was modified with LICA38 . Investigates indicated that the Volume Resistivity of (CuSna/bLc)xPEy is lower than (CuSna/b)xPEy. In addition, Volume Resistivity of (CuSna/b)xPEy prepared by ball milling method decreased with thickness increa. The Fourier Infrared（FTIR），differential scanning calorimetry （DSC）and multiple function micro-electrical resistance meter (KEITHLEY2700) were used to study the surface morphology, thermal and electrical properties of (CuSna/b)xPEy and (CuSna/bLc)xPEy.
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Syu, Ruo-syun, and 徐若勳. "Interfacial Reactions Between Sn-58 wt %Bi, Sn-0.7 wt% Cu Lead-free Solders and Alloy 42 Substrate." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/22083163577046639882.
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碩士<br>國立臺灣科技大學<br>化學工程系<br>97<br>In this research, we studied the interfacial reactions between Sn-58 wt% Bi and Sn-0.7 wt% Cu lead-free solders and Alloy 42 substrate. The liquid/solid reaction couples were reflowed for 1~50 hours at 240, 270, 300 and 330℃. In this study, the kinetic, reaction mechanism and the sort of the intermetallic component of the interfacial reactions were investigated. The experiment results indicated that only the FeSn2 phase was formed on the interfaces of the SB/Alloy 42 and SC/Alloy 42 couples. After etching process, there are two kind of morphology of the intermetallic component layer for each sample. In low reflowing temperature, there are chunk and plank type IMCs near the solder, and close to the substrate a flat, dense reaction layer are formed. The chunk, plank type IMCs are easy to spall away. The morphology of the IMC change to form column type grains and the spalling doesn’t happen when the reflow temperature increase. All the IMCs become thick with increasing temperature.
In the kinetics study, the couples of SB/Alloy 42 reflowed at 240℃ is grain boundary diffusion controlled. And the others are diffusion controlled.
Finally, we sputtered a Mo layer on the alloy 42 substrate. The layer of Mo act as a marker which indicated the origin position of the reaction. The experiment results demonstrated that Sn is the dominate diffusion atoms.
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Guo, Siao-wei, and 郭筱薇. "Developement of High-temperature Lead-free solders: Zn-Sn-Al-Cu Based Alloy." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/d63szw.
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碩士<br>國立臺灣科技大學<br>材料科學與工程系<br>99<br>Despite numerous studies on the research and development for high-temperature lead free solders, high-lead solder are still in used because high-temperature lead free solders also has been facing several serious problems during these years. Establishing high-temperature lead-free solder is an urgent priority. This study investigates the development of high-temperature lead-free solders and their properties by improve its wettability and oxidation resitivity after addition of Ni and Ge in Zn-Sn-Al-Cu based alloy. The solders are examined for microstructure, thermal properties, mechanical properties and investigate the interfacial reaction between Zn-Sn-Al-Cu based alloy with Cu and Ni/Cu at 300 and 350oC for 1, 2 and 4 hours.
The experimental results indicate that the liquilidus temperature of Zn-Sn-Al-Cu based alloys is between 275oC to 375oC with Zn content. As Zn contents increase the (Zn) and CuZn5 increase, therefore resulting in the increase of micro-hardness and ultimate tensile strength and the addition of Al improve mechanical properties. Three or four intermetallic compounds (IMCs) are formed at the interface in the Cu/alloy diffusion couple. The reaction phases are identified as CuZn5, Al4Cu3Zn, ??nphase and CuZn is formed facing to the Cu substrate. The ??nphase is formed or not that is related to Al/Zn ratio. The IMCs are indentified as CuZn5, Al4Cu3Zn, (Zn), (Al) and?n??Sn phase in the alloys near the Ni/Cu substrate after reflow.
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Hong, Wei-Cheng, and 洪偉城. "Study on the Alloy Bulks and Thin Film properties of Al-Co-Cu-Sn-Ti Equal-Mole Alloys." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/36702286434826442743.
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碩士<br>中國文化大學<br>材料科學與製造研究所<br>92<br>This thesis is according to the concept of equal-mole multi-principal alloys by Dr.Ye. Using this concept to compound the elements of Al,Co,Cu,Sn,Ti into equal-mole alloys. Five 4-component equal-mole alloys and one 5-component equal-mole alloy were selected for this paper equal-more alloys. We proceed to research of microstructures, analysis of phases, thermal property, the hardness and thermal electric property. However, AlCuSnTi had the best properties among these alloys. It is a four phase equal-mole alloy and this alloy was selected to cast it into target. Further we take it thin film sputtering and analysis of its property.
The results of Al-Co-Cu-Sn-Ti equal-mole alloys showed:
(1)They have higher hardness values, because the alloys contained different element, atom size was different and coursed solid-solution strengthening. Therefore, equal-mole alloys had higher hardness than that of tradition alloys. Under as-cast state, AlCoCuTi alloy and AlCoCuSnTi alloy were HV698 and HV368. (2) Respectively, The seebeck coefficient values of equal-mole alloys were not good enough. In this study, the maximum seebeck coefficient values of AlCoCuTi alloy was 25.7μv/k. (3) The alloys have nano grain structure from TEM observing, and the grain size is less than 10nm. AlCoCuTi and AlCoCuSn alloys had super-lattice structures. (4) In thin film sputtering, increase the power of sputtering or flow rate of Argon, it could improve the deposition rate of thin film.
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Alex, Sherine. "Development of Cu-based Intermetallic Reflector Materials for Concentrated Solar Power Application." Thesis, 2017. https://etd.iisc.ac.in/handle/2005/4277.
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The growing demand for energy is an important issue for the existence and development of humankind. In order to reduce the impact of conventional energy sources on the environment, attention should be paid to the development of new and renewable energy resources. Solar energy is a major environment friendly, renewable and sustainable energy source. Subsequently, with increasing drying up of the terrestrial fossil fuel, solar energy will potentially become an important part of the future energy structure. Concentrated solar power (CSP) technology is a productive way to make effective utilization of thermal energy from sun. Consequently, exploring high efficiency CSP technology is necessary. This has motivated the development of spectrally selective reflector and absorber materials.
Recently, reflectors have attracted considerable attention due to their potential application in CSP system. Reflector failure due to the formation of an oxide layer on metallic surfaces has been widely recognized as a major issue, often leading to CSP plant failure. Bronze (an alloy of copper and tin) mirrors, having lustrous reflective surface, were one of the candidate materials for traditional antique mirrors from ancient times. However, research involving these intermetallic materials for reflector application is still limited. The important drawbacks for these materials include complex processing conditions, brittleness, physical and chemical properties like oxidation, wettability etc. The phase composition, surface properties, free electrons density and hence the plasma frequency plays a critical role in controlling the reflectance of any materials. To this end, the main focus of this work was to develop reflector materials from alloys of Cu-Sn, Cu-Al, Cu-Sn-Zn or Cu-Sn-Al system and to understand the composition dependence reflectance properties of both bulk alloys and thin films of varying thickness.
In this perspective, the present dissertation demonstrates how one can adopt an alloy design approach to develop bulk optical reflector materials. Extending this to coatings, the efficacy of electrodeposition and thermal evaporation was also illustrated to show thickness dependent reflectance property. The importance of the development of new reflector materials for CSP technology is highlighted in chapter 1. The necessary theoretical fundamentals i.e., the physics aspect of the reflector functionality together with a review of the existing materials for reflector application are summarized in chapter 2. The general description of various experimental methodologies is made in chapter 3.
The first part of the present dissertation involves bulk alloy development and second part describes film fabrication. In a few cases, the scratch resistance and the influence of dust and humidity of the environment were also investigated. Chapter 4 demonstrates our attempt to develop a reflector material in the bulk cast form. This chapter describes the development of bulk Cu-Sn intermetallic for application as a solar reflector and further tuning them with tailored substitution of Zn or Al. A conventional metallurgical route (non-equilibrium processing techniques like vacuum arc melting and chill casting) was adopted. The second part (chapter 5 and 6) deals with thin film synthesis. The studies on intermetallic coatings of Cu-Sn alloys by electrodeposition are presented in chapter 5. Further, Cu-Al thin film deposition by thermal evaporation is explained in chapter 6. Some brief highlights of the major chapters of this dissertation are summarized below.
Chapter 4 mainly deals with the development of Cu-Sn intermetallic based solar reflector material, where further all substitution was performed using aluminium or zinc. Zinc was chosen due to its solid solution solubility with copper and aluminium was added because of its high plasma frequency. Chapter 4 essentially reports the rationale of reflector alloy design from a metallurgical and physics perspective. The results obtained with the baseline Cu41Sn11 intermetallic and other alloy compositions have been be analysed to bring out the influence of Al or Zn substitution to the baseline alloy. A detailed analysis of the phase assemblage utilizing Rietveld refinement of the X-ray diffraction (XRD) data and wavelength dispersive spectroscopy (WDS), attached to the electron probe micro analyser (EPMA) has been performed. The physical basis of higher reflectance has been explained on the basis of plasma frequency calculation of these alloy compositions. A good correlation between the phase abundance and plasma frequency was seen and is attributed to the high specular reflectance. Moreover, the Cu- 21.2 at % Al alloy composition, consisting of two phases Cu3Al (ωp = 6.47 x 1015 rad/sec) and Cu0.78Al0.22 (ωp = 19.25 x 1015 rad/sec) phases, exhibited 89.5% specular reflectance and 83% solar reflectance with roughness at nanometre level and a hardness of 2.1 GPa. These results establish the suitability of an alloy design approach to obtain a new class of intermetallic reflector materials with a tailored combination of bulk specular reflectance and hardness.
Chapter 5 was focussed on the development of lustrous Cu-Sn coatings from an acidic sulfate based electrolyte containing electro generated metal ions. The deposition of individual metals and co-deposition of metals were carried out. Importantly, it has been demonstrated that lustrous coatings can be galvanostatically electrodeposited from acidic sulfate based electrolyte in the presence of Laprol as an additive. The intricate designing of Cu-Sn codeposition was illustrated by systematic changes in the deposition conditions, such as applied current, bath composition and time of deposition. The quantitative analysis of the phase assemblage as well as compositional analysis of different phases was conducted using SEMEDS and XRD based Rietveld analysis. The coating thickness dependent surface morphology and specular reflectance was established. Essentially, we evaluated the properties such as scratch hardness and scratch adhesion, effect of dust and humidity, in reference to the projected CSP applications. Importantly, the useful combination of ~ 80 % specular reflectance and scratch resistance of Cu41Sn11 film were demonstrated to be highly durable under local environmental conditions.
In chapter 6, a facile fabrication of Cu-Al thin films on flex glass substrate was demonstrated by systematically varying the applied current and rate of deposition in a thermal evaporation route. The metallic Cu-Al ingot (obtained from arc melting) was heated in vacuum by applying current, and was thermally evaporated onto a flexible glass substrate to obtain the reflector coatings. In particular, the Cu0.78Al0.22 thin films with a plasma frequency ωp = 19.25 x 1015 rad/sec, were fabricated on flexible glass substrates by resistive thermal evaporation. An attempt was made to analyze the relationship among the phase compositions, surface morphology, thickness, surface coverage and optical properties. Importantly, flexible Cu0.78Al0.22 films with a specular reflectance of ~ 84 % in the solar region and scratch resistance at 900 mN load were obtained. It can be envisioned that with all these promising features, the Cu-Al films promise a great potential for use as highly reflective and flexible material for thin-film reflecting concentrators, solar energy devices and other optical mirrors.
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Chen-YiLin and 林宸禕. "The Effect of Electromigration on the Interfacial Reaction between Sn-Ag-Cu-Ni-In Alloy and Ni Substrate." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/42459580931946486108.
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Ray-WenWu and 吳瑞文. "Effect of Arc-melting Tin and Copper on the Microstructure and Properties of Ti-Sn-Cu alloy during the As-casting and Heat Treatment." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/2p5cym.
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TE, JEN, and 陳仁德. "Study of Hardness on Sn(Cu) Alloys." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/55404740554883362350.
Full textAbstract:
博士<br>國立中央大學<br>化學工程與材料工程研究所<br>97<br>Solder jointing technology is very important for the modern electronic industry.
Due to Pb has a toxic nature and the environmental and health hazard concerns. So,
Pb-free solders are developed to replace SnPb. Yet, high strength mechanical
property, the superior creep resistance and thermal fatigue are the important issues for
the solder joint reliability. On the other hand, silver would be very costy in the
future. The low-cost Sn(Cu) alloys offer good advantages for the future Pb-free
solders. However, Cu and Ni are often used in the bond pads on the chip and broad
side for the current flip-chip interconnect structure. It has been reported that the
solder microstructure (Sn phase and eutectic structure) near the Ni side is weaker than
that near the Cu. But, we do not clearly understand the relation between solder joint
microstructure with hardness along Ni and Cu bond pad. So, the main objective of
this thesis is to study the correlation between the hardness and the microstructure of
Sn(Cu) alloys.
The microstructure of hyper-eutectic and hypo- eutectic of Sn(Cu) alloys are
investigated under different cooling rates and aging times. For the hypo-eutectic
Sn(Cu) alloys (Sn0.4Cu and Sn0.7Cu ), their microstructure mainly contain the
primary Sn grains and the eutectic structure. The eutectic structure is composed of
Sn phase and Cu6Sn5 compound phase. The major reason for the appearance of Sn
grains in the eutectic Sn0.7Cu should be due to the non-equilibrium cooling during
the solidification process of Sn0.7Cu alloy. Furthermore, for the Sn1.0Cu alloy,
round primary Cu6Sn5 particles was uniformly exhibited in Sn1.0Cu. For Sn1.4Cu
and Sn2.1Cu alloys, contain chunky Cu6Sn5 particles and eutectic structure of Sn and
Cu6Sn5 compound phase. It found that the hardness initially would increase with Cuadditives in Sn(Cu) alloys. As the Cu concentration reaches 1.0 wt%, the hardness
has a maximum value. Then, hardness started decreasing with Cu concentration.
According to our hardness testing results, the hardness is inversely proportional
to the Cu6Sn5 compound particle size and space. Thus, the hardness can be further
formulated as Rn
H = k4 1 and Ln
H = k3 1 , respectively. From Sn1.0Cu results
shown previously, it was further formula as empirical equation can be expressed as :
or , In conclusion, we formulate an the empirical
equation for regulating the hardness of Sn(Cu) solder alloys ;
and
or and .
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Huang, Sheng-Fang, and 黃聖芳. "Constituting Phases of Cu-Sn-Ti Alloys." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/28370977643119694204.
Full textAbstract:
博士<br>國立臺灣科技大學<br>機械工程系<br>91<br>This study examines the constituting phases in the Cu-Sn-Ti alloys. Three Cu-Sn-Ti alloys of different compositions, namely Cu-17Sn-23Ti、Cu-5Sn-20Ti and Cu-20Sn-5Ti (numbers are all in atomic percent unless specified otherwise), were heat-treated in vacuum. There were divided into two groups for different heat treatment. One group of specimens were heat-treated at an isothermal holding temperature of 900℃ and held for either 5 minutes, 1 hour, 3 hours, 6 hours, or 10 hours. The other group of specimens were heat-treated at an isothermal holding temperature of either 600℃, 700℃, 800℃, 900℃, or 1000℃, and held for 10 hours. Both groups of specimens were subsequently furnace-cooled to room temperature. To further examine the phase evolution during the cooling process, a fraction of the furnace-cooled specimens were heated again from room temperature to 900℃, held at 900℃ for 15 minutes, and then quenched in water. The specimens were split in longitudinal sections for observing the macrostructure as well as wettability. Microstructures of the specimens were examined by scanning electron microscope. Compositional analysis of the constituting phases in the alloys subsequent to heat-treatment was carried out using an electron probe microanalyzer. X-ray diffraction and transmission electron microscope were employed to detect the crystal structure of the specimens. The phase transformation of the alloys was recorded by a differential scanning calorimeter (DSC).
Experimental results revealed that the wetting angle is about 60° between Cu-17Sn-23Ti alloy and graphite crucible. There were five constituting phases in the Cu-17Sn-23Ti alloy, which included intermetallic compounds CuSnTi3, Cu2SnTi3, CuSn3Ti5, Cu41Sn11 and solid solution Cu-9Sn. Cu2SnTi3 is a newly discovered phase with hexagonal lattice type, and lattice constants a=4.708Å, and c=6.756Å. The mean grain size and relative abundance of Cu2SnTi3 decreased with increase in holding time at 900℃. CuSnTi3 is also a new-found phase with hexagonal lattice type, and lattice constants a=4.636Å, and c=5.229Å. CuSnTi3 existed as large faceted grains and was more stable than Cu2SnTi3 at holding temperature higher than 900℃. Cu2SnTi3 grains transformed into CuSnTi3 when isothermal holding temperature increased to 900℃, and held for a longer time. The transformation temperatures of Cu2SnTi3 and CuSnTi3 as recorded by the DSC were 722℃ and 811℃, respectively. There were two other constituting phases, Cu41Sn11 and Cu-9Sn, in the furnace-cooled specimen, which were thought to be the result of an eutectoid reaction of the Cu-rich matrix. There was only one phase, Cu-14Sn, within the matrix because no eutectoid reaction occurred when the specimen was quenched from 900℃.
The wetting angle is about 10° between Cu-5Sn-20Ti alloy and graphite crucible. There were four constituting phases in the Cu-5Sn-20Ti alloy, which included intermetallic compounds Cu2SnTi3, CuSn3Ti5, CuTi and solid solution Cu-4Ti. The mean grain size and relative abundance of CuTi, which existed as small grains, increased gradually with increase in holding time at 900℃. When the isothermal holding temperature increased from 600℃ to 900℃ and held for 10 hours, the mean grain size and relative abundance of CuTi increased evidently, while Cu2SnTi3 disappeared. Cu2SnTi3 grains transformed into CuTi when isothermal holding temperature increased to 900℃, and after a longer holding time.
The wetting angle is about 8° between Cu-20Sn-5Ti alloy and graphite crucible. There were only three constituting phases in the Cu-20Sn-5Ti alloy, which included intermetallic compounds Cu41Sn11, CuSnTi and solid solution Cu-9Sn, regardless of the temperature and holding time. CuSnTi coalesced gradually into hexagonal grains with increase in either isothermal holding temperature or holding time at 900℃. There were two other constituting phases, Cu41Sn11 and Cu-9Sn, in the Cu-20Sn-5Ti alloy, which were also attributed to an eutectoid reaction of the Cu-rich matrix during the furnace-cooling process.
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LI, jia-feng, and 李佳峰. "Wettability and Constituting phases of Cu-Sn-Ti Alloys." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/47316013080259127316.
Full textAbstract:
碩士<br>中華技術學院<br>機電光工程研究所碩士班<br>95<br>Abstract
This study examines the wettability and constituting phases in the Cu-Sn-Ti alloys. Seven Cu-Sn-Ti alloys of different compositions were heat-treated in vacuum furnace. Then were heat-treated at an isothermal holding temperature of 900℃ and held for 1 hour, and were subsequently furnace-cooled to room temperature. Microstructures of the specimens and compositional analysis of the constituting phases in the alloys were examined by electron probe microanalyzer. Experimental results revealed that the Cu-30Sn-10Ti alloy achieved the smallest wetting angle of 8°. There were eight constituting phases in the Cu-Sn-Ti alloys, which included intermetallic compounds CuSnTi3, Cu2SnTi3, CuSn3Ti5, CuSnTi, CuTi, Cu41Sn11, and solid solution Cu-Ti and Cu-Sn, etc.
Key word: Brazing, Diamond tool, Wetting angle, Cu-Sn-Ti alloys.
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Pan, Kai-Wen, and 潘凱文. "Directional solidification and liquidus projection of Sn-Co-Cu and Sn-Co-Ni alloys." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/42921672435896364873.
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Lee, Yen-Yu, and 李彥佑. "Surface oxidation of molten Sn(Ag, Ni, In, Cu) alloys." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/87x84q.
Full textAbstract:
碩士<br>國立中央大學<br>材料科學與工程研究所<br>97<br>The surface oxidations of molten Sn(Ag, Ni, In, Cu) alloys are studied. We conclude that the microstructure (phase and density) of the surface oxide layer is the key factor for the surface oxidation formation. And, we found that the microstructure (phase and density) of the Sn surface oxide layer is highly influenced by the additives in the solder alloys, which can be roughly anticipated from the additives’ EMF values and Gibbs free energies of oxide formation. The detail effect (either retarding or enhancing) of the additives on the surface oxidation would be discussed and proposed in this paper.
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申有田. "Liquidus projection and solidification properties of In-Sn-Cu alloys." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/79816117725812488347.
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Yang, Shengyuan, and 楊盛淵. "A study of internal oxidation in Cu-Al-Ag and Cu-Al-Sn alloys." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/33764910886880491327.
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Hsien-Ming, Hsiao, and 蕭憲明. "The Phase Equilibria of the Au-Cu-Sn Ternary System, the Ag-Au-Cu-Sn Quaternary System, and the Interfacial Reaction between Sn-Cu Alloys and the Au Substrate." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/99356988147809093775.
Full textAbstract:
碩士<br>國立臺灣科技大學<br>化學工程系<br>93<br>Sn-Ag-Cu ternary and Sn-Cu binary alloys are the commercial Pb-free solders and widely used in electronic industries. The Au is commonly used in flip-chip technology, tape automated bonding as under bump metallurgy and substrate materials in printed circuit boards. In this study, the phase equilubria of the Sn-Cu-Au ternary, Sn-Ag-Cu-Au quaternary system, and interfacial reactions between Sn-Cu alloys and Au were experimentally investigated at specific temperatures. The experimental results indicate that there exists a complete solid solubility between AuSn and Cu6Sn5 at 200℃. At least two ternary intermetallic compounds having the homogeneity ranges Au35Cu45Sn20-Au20Cu60Sn20, and Au34Cu33Sn33-Au32Cu35Sn33, are found at 200℃.
The several Sn-Cu/Au reaction couples were prepared and reacted at 150, 180, 200℃ for various lengths of time. Three intermetallic compounds, AuSn, AuSn2, AuSn4 are found in all couples, and (Au,Cu)Sn/(CuxAu1-x)6Sn5 is found in all Sn-Cu/Au couples except the Sn/Au couple. The thicknesses of these reaction layers increases with higher temperature and longer reaction time, and the growth mechanism can be described by using the parabolic law. The Sn-0.7 wt%Cu/Au couple has the lowest activation energies. This result is probably due to the eutectic composition of the Sn-Cu alloy is Sn-0.7wt%Cu. In addition, with increasing reaction time, the intermetallic compound AuSn4 disappears gradually, and turns into (Au,Cu)Sn and (CuxAu1-x)6Sn5. Experimental results also indicate that added more Cu in the solders reduces the total IMCs’ thicknesses and thicker (CuxAu1-x)6Sn5 layer is observed. It seems that (CuxAu1-x)6Sn5 is the diffusion barrier in Sn-Cu/Au reaction coupled system.
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Yang, Ta-Kai, and 楊達凱. "Effect of Sn addition on the Cu-Zr-Ti amorphous alloys." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/a2863n.
Full textAbstract:
碩士<br>大同大學<br>材料工程學系(所)<br>93<br>This study examined the effect of Sn element addition on the Cu-Zr-Ti amorphous alloys by mechanical alloying technique. The microstructural evolution during mechanical alloying of the mixed powders was investigated by both X-ray diffraction and scanning electron microscopy (SEM).The phase stabilities of the as-milled powders were studied by DSC measurement. According to the result, after 5 hours of milling, the composition of Cu-Zr-Ti-Sn alloys were all amorphization. The thermal stability of the Cu-Zr-Ti-Sn amorphous powder was also investigated by differential scanning calorimeter (DSC). As the results demonstrated, the amorphous powder were found to exhibit a wide supercooled liquid region before crystallization. The temperature interval of the supercooled liquid region was defined by the difference between Tg and Tx. The highest value of △T was found to exhibit at Cu46Zr30Ti20Sn4 alloys system (93K). Finally, the small addition of Sn element significantly improved the glass forming ability (GFA) of Cu-Zr-Ti amorphous alloys.
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Wang, Kai-Hong, and 王凱弘. "Brazing Ti-6Al-4V with Cu-Sn-Ti alloys as filler metal." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/53982229988248506029.
Full textAbstract:
碩士<br>中華技術學院<br>機電光工程研究所碩士班<br>97<br>This study mainly develops the Cu-Sn-Ti alloys as filler metals to braze Ti-6Al-4V alloy. Four Cu-Sn-Ti alloys of different compositions were used to braze Ti-6Al-4V alloy in vacuum furnace. The brazing process was carried out to heat with a rate of 30℃/min from room temperature to 600℃ and held for 30 minutes, then keep heating to brazing temperature, and heat-treated at an isothermal holding temperature of either 850℃, 900℃, or 950℃, and held for 30 minutes. The specimens were subsequently furnace-cooled (cooling rate of 4℃/min) to room temperature. The specimens were split in longitudinal sections for observing the macrostructure as well as wettability. Microstructures of the specimens were examined by scanning electron microscope. Compositional analysis of the constituting phases in Cu-Sn-Ti alloys, and interface between filler metal and Ti-6Al-4V alloy was carried out using an electron probe micro-analyzer. X-ray diffraction was employed to detect the constituting phases of the Cu-Sn-Ti alloys. The phase transformation of the alloys was recorded by a differential scanning calorimeter. The hardness of specimens was measured by a micro-Vickers hardness tester.
The results revealed that the lowest wetting angel is approximately 16° between Cu-10Sn-20Ti and Ti-6Al-4V alloy after brazed at 900℃. The micro hardness of Cu-10Sn-20Ti is highest among these four Cu-Sn-Ti alloys. There were five constituting phases in the Cu-Sn-Ti alloy, witch included three intermetallic compounds: CuSn3Ti5, Cu2SnTi3, CuTi and two solid solutions: Cu-5Ti and Cu-9Sn. The major constituting phases of the interface included intermetallic compounds: Ti3Sn and CuTi, and solid solution Cu-Ti, Ti-V, Ti-Sn and Ti-Al etc.
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Lin, Chih-Hao, and 林志豪. "Phase equilibria and solidification properties of the ternary Sn-Cu-Ni alloys." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/80848053773786767842.
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Chang, Shu-hau, and 張書豪. "Study of Interfacial Reactions between Sn-Ag-Cu Alloys and the Au Substrate." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/07085016564123286303.
Full textAbstract:
碩士<br>國立臺灣科技大學<br>化學工程系<br>93<br>ABSTRACT
This study investigated interfacial reactions between Sn-Ag-Cu alloys and Au substrate. It's distinguished three systems that different concentration of Sn. The reaction time is 12 hour to 1200 hour, reacted at 150,180 and 200°C.After reaction，we analyze the species of IMCs and observe morphology of IMCs.
Reacted at 200°C, five phases, AuSn /AuSn2 / AuSn4 / (AuCu)Sn /(CuxAu1-x)6Sn5,are found between Au substrate and Sn-Ag-Cu Alloys. Reacted at 180°C，increase the Cu concentration in alloy will restrain the formation of AuSn4. Four phases, AuSn /AuSn2/(AuCu)Sn/(CuxAu1-x)6Sn5
are found between Au substrate and Sn-Ag-Cu Alloys.Reacted at 150°C, increase the Cu concentration in alloy will restrain the formation of AuSn2. Three phases, AuSn /(AuCu)Sn/(CuxAu1-x)6Sn5 are found between Au substrate and Sn-Ag-Cu Alloys.
The thickness of the reaction layers increases with higher temperatures and longer reaction time, and their growth rates are described by using the parabolic law. Based on the reaction path knowledge and interfacial morphology, it is concluded that Sn is the fastest diffusion species in the couples.The thickness of the reaction layers decrease when the concentration of copper in alloy increase. But the thickness of (AuCu)Sn/(CuxAu1-x)6Sn5 phase increase.. Maybe, it result from barrier effect of (AuCu)Sn/(CuxAu1-x)6Sn5 phase. (AuCu)Sn/(CuxAu1-x)6Sn5 phase also restrain Au diffuse to alloy.
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徐煒能. "Effects of anisotropic Beta-Sn alloys on Cu diffusion under a temperature gradient." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/33735833478425329300.
Full textAbstract:
碩士<br>國立清華大學<br>工程與系統科學系<br>102<br>As the packaging technology transitions toward the three-dimensional integrated circuit (3D IC), a larger temperature gradient is expected to be established when the heat is dissipated from the surface of the stacking module. Furthermore, one solder bump consists of only few grains when the size of the solder bump shrinks into few micrometers. The crystal structure of β-Sn is known to be body-centered tetragonal (BCT) structure and it is anisotropic. Therefore, the effect of anisotropy of Sn is an important issue in the reliability of next-generation packaging technology.
We study the samples with a structure of Cu/Sn3.5Ag/Cu at a presence of temperature gradient. The experimental results and theoretical analysis indicated that thermomigration of Cu was strongly affected by anisotropic structure of Sn. When the c-axis of Sn grain was parallel to the direction of temperature gradient, a large thermomigration flux was induced and Cu atoms were driven to migrate from hot end to cold end. The migration resulted in a prominent asymmetrical feature in microstructure; serious dissolution of intermetallic compounds (IMC) and severe consumption of Cu substrate occurred at hot end whereas accumulation and growth of IMC were observed at cold end. On the other hand, when c-axis of Sn was perpendicular to temperature gradient, thermomigration was strongly mitigated due to a small induced flux. A near symmetrical feature in microstructure was found. Neither dissolution of hot-end IMC, nor abnormal growth of cold-end IMC was observed.
The morphology of hot-end interface was discussed in more details. Different from the serrated dissolution often resulted from electromigration, a relative flat interface remained after thermomigration. The Gibbs-Thomson effect and thermomigration were taken into account to explain the morphological change and IMC dissolution at hot end. Furthermore, the immobile Ag3Sn at the presence of the temperature gradient was found to suppress the thermomigration of Cu.
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Lai, Yan-Bo, and 賴彥伯. "Effect of Sn, Si and B addition on the Cu-Ti-Ni Amorphous alloys." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/77059099984641209344.
Full textAbstract:
碩士<br>大同大學<br>材料工程學系(所)<br>96<br>This study examined the amorphization behavior by adding Sn, B, and Si elements to Cu50Ti40Ni10 alloy powders synthesized by mechanical alloying technique. According to the results, the mechanical alloyed powders were amorphous at compositions (Cu50Ti40Ni10)95SnxB5-x (x=0-5), (C95Snu50Ti40Ni10)95SnxSi5-x (x=0-4), and (Cu50Ti40Ni10)95SixB5-x (x=1, 2, 4). The amorphous powders were found to exhibit a wide supercooled liquid region before crystallization. The temperature interval of the supercooled liquid region (ΔTx) is 59K((Cu50Ti40Ni10)95B5), 78K((Cu50Ti40Ni10)95Sn1B4), 72K((Cu50Ti40Ni10)95Sn2B3), 81K((Cu50Ti40Ni10)95Sn4B1), 79K((Cu50Ti40Ni10)95Sn5), 58K((Cu50Ti40Ni10)95Sn3Si2), 77K((Cu50Ti40Ni10)95Sn4Si1), 66K((Cu50Ti40Ni10)95Si1B4). Besides, based on
△Tx, the Sn-additive Cu based alloys have the best glass forming ability, followed by B-additive alloys and then by Si-additive alloys.
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Hsieh, Yu-chan, and 謝育展. "Constitutional Phases and Performances of Cu-Sn-Ti Alloys in the Brazing of Diamond." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/53589739739771918835.
Full textAbstract:
博士<br>國立臺灣科技大學<br>機械工程系<br>96<br>Cu-Sn-Ti alloys are ideal brazing filler suitable for bonding application of diamond because of its high wetting and bonding abilities. This study discussed the effects of various composition of Cu-Sn-Ti alloys on the wetting phenomena of graphite, its constitutions, and their interfaces at the temperature ranging from 850~1000℃.
It was found that the additions of Titanium enhancing the wetting ability of Cu-Sn-Ti alloys; however, although the additions of Tin could lower the melting temperature of the Cu-Sn-Ti alloys, it deteriorated the interface of between graphite and Cu-Sn-Ti alloys caused to affect the chemical bonding of the interface. When the content of Cu-Sn-Ti alloys was at constant low Tin concentration (10at.%), the Titanium addition produced the growth of hard intermetallic compound (IMC) phases, CuSn3Ti5, Cu2SnTi3, and SnTi3; when the content of Cu-Sn-Ti alloys was at constant low Titanium concentration (10at.%), the Tin addition produced the growth of brittle intermetallic compound (IMC) phases, Sn5Ti6 and Sn3Ti2, in the soft matrix. The result was found that the crack was easily occurred at the boundary of graphite and alloys if the constitution had lots of hard intermetallic compound phase (IMC).
To verify the experiment results, four kinds of most used brazing fillers were used to bond CVD diamonds for testing bending strength. The test results indicated that the bending strength of joining CVD diamonds by using Cu-10Sn-15Ti (wt.%) pre-alloys was higher than those by using two kinds of Ni-Cr based alloys, Ni-7Cr-3B-3Fe-0.5Si (wt.%) alloys and Ni-14Cr-10P (wt.%) alloys, but it had the similar value of the bending strength between CVD diamonds, which used Ag-34.25Cu-1In-1.75Ti (wt.%) alloys as brazing filler for CVD diamonds.
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Hsieh, Peiyin, and 謝佩吟. "Analysis Of Cu, Zn, Fe And Sn In Alloys By Powerchip Laser-induced Breakdown Spectrometry." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/62175628571093261767.
Full textAbstract:
碩士<br>靜宜大學<br>應用化學系<br>100<br>Laser-induced breakdown spectroscopy (LIBS) has numerous advantages such as no sample pretreatment, remote measurement, non-intrusive, minimal sample volume and multi-elemental analysis. In recent years, LIBS has become one of the most popular research subjects in analytical chemistry. LIBS can be miniaturized by using a powerchip laser instead of bulky conventional laser systems. The powerchip laser, which offered low energy pulses and high pulse repetition frequency (up to several kHz), was feasible for sample detection at atmospheric pressure in air, but there were still many problems yet to overcome. In this work, powerchip LIBS and conventional LIBS were compared for the analysis of copper alloys. This work determined Cu, Zn, Fe and Sn contents in copper alloys. The atomic emission lines identified in this work for the elements in copper alloys were Cu I 324.75 nm, Cu I 327.40 nm, Zn I 330.26 nm, Zn I 334.50 nm, Fe I 236.95 nm, Sn I 283.99 nm and Sn I 286.33 nm, respectively. In addition, the influence of laser focusing position, the influence of the different moving speed of stage on signal intensity, quantitative analysis and ablation efficiency were also studied.
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Peng, Yu-Chang, and 彭育彰. "Effect of Minor Mg on the Various Properties of Sn-Cu Lead-Free Solder Alloys." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/sb7b2b.
Full textAbstract:
碩士<br>國立虎尾科技大學<br>材料科學與綠色能源工程研究所<br>100<br>The research was focused on the effects of Mg additions to Sn-0.7Cu lead-free solder on the melting point, microstructure, mechanical property, and joint performance. Results of differential scanning calorimeter analysis showed that alloying of Mg to Sn-0.7Cu decreased the melting temperature slightly where the melting temperature was 227.88 °C. The microstructures of Sn-0.7Cu and Sn-0.7Cu-0.01Mg solders could be clearly divided into two regions, it was identified that the dendrite arm was primary β-Sn phase while the interdendritic eutectic was the Cu6Sn5/β-Sn eutectic phase. However, the eutectic regions of ternary eutectic Sn-3Ag-0.5Cu solder were a mixture of fine intermetallic particles of Cu6Sn5 and Ag3Sn in the β-Sn matrix. The wetting property was improved by addition of Mg element into the Sn-0.7Cu solder alloy. The addition of Mg enhanced the elongation of the solders but decreased their tensile strength. The intermetallic compounds thickness gradually increased with the increase of aging time. The tensile strength of the joints decreased with the increase of aging time while the fracture site was moved from solder alloy to intermetallics interface.