Effects of temperature on interfacial reactions in γ–InSn4/Ni couples

2006 ◽  
Vol 21 (5) ◽  
pp. 1161-1166 ◽  
Author(s):  
Sinn-wen Chen ◽  
Shih-kang Lin
Keyword(s):  
Liquid Phase ◽  
Reaction Layer ◽  
Reaction Path ◽  
Interfacial Reactions ◽  
Phase Layer ◽  
Homogeneous Phase ◽  
Nickel Substrates ◽  
Solid Phases ◽  
Effects Of Temperature

Interfacial reactions in γ–InSn4(Sn–20 at.% In)/Ni couples at 130, 140, 150, and 160 °C were investigated. Ni3Sn4phase with significant indium solubility was formed in the couple reacted at 130 and 140 °C, and the reaction path was γ–InSn4/Ni3Sn4/Ni. For the couples reacted at 150 and 160 °C, even though both γ–InSn4and Ni were solid phases, the liquid phase was formed in the couples. A distinguished feature was the nickel substrates becoming nonplanar with spikes at various locations and the Ni3Sn4phase layer on top of the nickel spikes. Except at regions near the nickel spikes, the reaction layer consisted of precipitates and was not a homogeneous phase. The reaction path is γ–InSn4/Ni3Sn4/Ni at the location with Ni3Sn4phase growing on Ni. However, if the Ni3Sn4phase does not nucleate, the liquid phase forms at the interface with accumulation of indium atoms, and the reaction path is γ–InSn4/ liquid/liquid + Ni3Sn4/Ni.

Interfacial reactions in the Sn–20 at.% In/Cu and Sn–20 at.% In/Ni couples at 160 °C

2006 ◽  
Vol 21 (7) ◽  
pp. 1712-1717 ◽  
Author(s):  
Shih-kang Lin ◽  
Sinn-wen Chen
Keyword(s):  
Melting Point ◽  
Liquid Phase ◽  
Reaction Rate ◽  
Reaction Path ◽  
Interfacial Reactions ◽  
Phase Layer ◽  
Electronic Products ◽  
Ni Substrate ◽  
Consumption Rates ◽  
Peculiar Phenomenon

Sn–In alloys are promising low-melting-point Pb-free solders. Cu and Ni are common substrates in the electronic products. This study examines the interfacial reactions in the Sn–20 at.% In(γ–InSn4)/Cu and Sn–20 at.% In/Ni couples at 160 °C. Only the η–Cu6Sn5 phase layer is formed in the Sn–20 at.% In/Cu couple, and the layer grows thicker with longer reaction time. The reaction path is γ–InSn4/η–Cu6Sn5/Cu. A peculiar phenomenon with the bulging of the couple near the Ni substrate is found in the Sn–20 at.% In/Ni couple. A liquid phase is formed by interfacial reaction in the solid/solid Sn–20 at.% In/Ni couple at 160 °C, and the reaction path is γ–InSn4/liquid/δ–Ni3Sn4 + liquid/(δ–Ni3Sn4)/Ni. Usually Ni has a slower reaction rate with solders; however, the consumption rates of Ni substrate are much higher than those of Cu substrate in this study when they are in contact with the Sn–20 at.% In alloy at 160 °C due to the formation of the liquid phase in the Sn–20 at.% In/Ni couple.

Electric current-induced abnormal Cu/γ-InSn4 interfacial reactions

2006 ◽  
Vol 21 (12) ◽  
pp. 3065-3071 ◽  
Author(s):  
Sinn-wen Chen ◽  
Shih-kang Lin
Keyword(s):  
Liquid Phase ◽  
Grain Boundaries ◽  
Electric Current ◽  
Reaction Path ◽  
Interfacial Reactions ◽  
Melting Points ◽  
Transport Enhancement ◽  
Current Stressing ◽  
Phase Layers ◽  
Electromigration Effect

The electromigration effect upon the γ-InSn4/Cu interfacial reactions have been studied by examining the γ-InSn4/Cu/γ-InSn4 couples annealed at 160 °C with and without current stressing. Scallop-type η-Cu6(Sn,In)5 phase layers are formed in the couples without current stressing and at the γ-InSn4/Cu interface where electrons are flowing from the γ-InSn4 to the Cu. The reaction path is Cu/η-Cu6(Sn,In)5/γ-InSn4. However, very large η-Cu6(Sn,In)5 compounds are found at the Cu/γ-InSn4 interface where electrons are from Cu to the γ-InSn4. Although the melting points of both γ-InSn4 and Cu are higher than 160 °C, the liquid phase is formed at 160 °C in the electrified couple at the downstream γ-InSn4 phase near the Cu/γ-InSn4 interface. The reaction path is Cu/η-Cu6(Sn,In)5/liquid/γ-InSn4. The liquid phase propagates along the grain boundaries of the γ-InSn4 matrix. The very large η-Cu6(Sn,In)5 compounds are the coupling results of the liquid phase penetration and the Cu transport enhancement due to electromigration.

scholarly journals Removal of Tramp Elements within 7075 Alloy by Super-Gravity Aided Rheorefining Method

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 701 ◽  
Author(s):  
Lei Guo ◽  
Xiaochun Wen ◽  
Qipeng Bao ◽  
Zhancheng Guo
Keyword(s):  
Heat Treatment ◽  
Liquid Phase ◽  
7075 Aluminum Alloy ◽  
Total Removal ◽  
Tramp Element ◽  
Removal Ratio ◽  
Gravity Coefficient ◽  
Flow Through ◽  
Solid Phases ◽  
7075 Alloy

An investigation was made on the super-gravity aided rheorefining process of recycled 7075 aluminum alloy in order to remove tramp elements. The separation temperatures in this study were selected as 609 °C, 617 °C and 625 °C. And the gravity coefficients were set as 400 G, 700 G, 1000 G. The finely distributed impurity inclusions will aggregate to the grain boundaries of Al-enriched phase during heat treatment. In the field of super-gravity, the liquid phase composed of tramp elements Zn, Cu, Mg et al. will flow through the gaps between solid Al-enriched grains and form into filtrate. Both the weight of filtrate and removal ratio of tramp element improved with the increase of gravity coefficient. The total removal ratio of tramp element decreased with the fall of temperature due to the flowability deterioration of liquid phase. The time for effective separation of liquid/solid phases with super-gravity can be restricted within 1 min.

scholarly journals Interfacial Reactions between Mg-40Al and Mg-30Y Master Alloys

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 825 ◽  
Author(s):  
Jiahong Dai ◽  
Bin Jiang ◽  
Hongmei Xie ◽  
Qingshan Yang
Keyword(s):  
Diffusion Couple ◽  
Reaction Layer ◽  
Intermetallic Phase ◽  
Diffusion Path ◽  
Interfacial Reactions ◽  
Diffusion Activation Energy ◽  
Temperature Phase ◽  
Diffusion Couples ◽  
Master Alloys ◽  
Growth Constants

Interfacial reactions between Mg-40Al and Mg-30Y master alloys were investigated at intervals of 25 °C in the 350–400 °C by using a diffusion couple method. Noticeable reaction layers were formed at the interfaces of the diffusion couples. The concentration profiles of the reaction layers were characterized. The diffusion path of the diffusion couple at 400 °C is constructed on the Mg-Al-Y ternary isothermal temperature phase diagram. The phases of the reaction layer were characterized by X-ray diffraction. The interfacial reaction thermodynamics of diffusion couples were studied. These results indicate that Al2Y is the only new formed intermetallic phase in the reaction layers. The growth constants of the reaction layers were calculated. In the reaction layer II, the integrated interdiffusion coefficients of Al are higher than Y, the diffusion activation energy of Y is higher than that of Al.

Calphad description of the Ge-Mn system

2014 ◽  
Vol 1642 ◽  
Author(s):  
Alexandre Berche ◽  
Jean-Claude Tédenac ◽  
Philippe Jund ◽  
Stéphane Gorsse
Keyword(s):  
Phase Diagram ◽  
Liquid Phase ◽  
Thermodynamic Properties ◽  
Gibbs Energy ◽  
Critical Review ◽  
Thermodynamic Description ◽  
Calphad Method ◽  
Review Of The Literature ◽  
Solid Phases

ABSTRACTThe germanium-manganese system has been experimentally studied but no Calphad description is available yet. After a critical review of the literature concerning the phase diagram and the thermodynamic properties, a thermodynamic description of the Gibbs energy of the phases is performed using the Calphad method. The liquid phase is described with an associated model and the variation to the stoichiometry of the solid phases is taken into account.

Cruciform pattern formation in Sn/Co couples

2007 ◽  
Vol 22 (12) ◽  
pp. 3404-3409 ◽  
Author(s):  
Chao-hong Wang ◽  
Sinn-wen Chen
Keyword(s):  
Pattern Formation ◽  
Reaction Layer ◽  
Phase Region ◽  
Solid Reaction ◽  
Phase Layer ◽  
Reaction Phase ◽  
Phase Layers ◽  
Continuous Reaction ◽  
First Time

CoSn3 phase is formed in Sn/Co couples reacted at 200 °C. The reaction phase shows a unique cruciform pattern that is observed for the first time in the solid/solid reaction. The reaction phase layers are thick and uniform along the edges of the Co substrate, and there are no reaction phases at the corners. A continuous reaction layer is formed in Sn/Co couples reacted at 180 °C. A metastable CoSn4 phase is formed at the corner, and the reaction phase along the edge of the Co substrate is the CoSn3 phase. The reaction CoSn3 phase region shows a cruciform pattern if the CoSn4 phase region is ignored. It is concluded that the Sn flux is much faster than the Co flux, and the cruciform pattern of the reaction CoSn3 phase layer is formed either by cracking or transformation to the CoSn4 phase at the corners where stresses are most intensified.

scholarly journals Application of equilibrium phase diagrams for calculation of segregation kinetics during two-component melt cooling

2020 ◽  
Vol 63 (2) ◽  
pp. 129-134
Author(s):  
A. D. Drozin ◽  
E. Yu. Kurkina
Keyword(s):  
Liquid Phase ◽  
Equilibrium State ◽  
Cross Section ◽  
Diffusion Coefficients ◽  
Solid Phase ◽  
Equilibrium Phase ◽  
Minimum Size ◽  
Two Component ◽  
Solid Phases ◽  
Liquid And Solid Phases

According to the equilibrium state diagrams, when the melt is cooled to a certain temperature below liquidus, compositions of liquid and solid phases are uniquely determined by corresponding curves in the diagram. However, it does not happen in reality. For equilibrium (which the diagram describes), it is necessary that the melt is maintained indefinitely at each temperature, or thermal conductivity of liquid and solid phases, and the diffusion coefficients of their components, are infinitely large. We made an attempt to find out how these processes occur in reality. In this work, we consider the growth of individual crystal during cooling of a two-component melt. Mathematical model is constructed based on the following. 1. The melt area with volume corresponding to one grain, the periphery of which is cooled according to a certain law, is considered. 2. At the initial instant of time, a crystal nucleus of a certain minimum size is in the liquid. 3. At the surface of crystal, compositions of liquid and solid phases correspond to equilibrium state diagram at a given temperature on its surface. 4. Changes in temperature and composition in liquid and solid phases occur according to the laws of heat conduction and diffusion, respectively. As the melt gets cold and the crystal grows, the liquid phase is enriched in one component and depleted in another, the solid phase – on the contrary. Since the diffusion coefficients of the components in the solid phase are small, the composition of the crystal does not have time to completely equalize its cross section. The model proposed in the work allows us to study this phenomenon, to calculate for each cooling mode how the composition of the crystal will vary over its cross section. The calculations have shown that the temperature equalization occurs almost instantly, and composition of the liquid phase equalizes much slower. Equalization of the solid phase composition does not occur in the foreseeable time. The results of the work will help to improve technology of generation of alloys with an optimal structure.

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