In this study,SEM,EDS,XRD and other test methods were used to study the effects of different Ga contents(0~2 wt.%)on microstructure,electrical conductivity,spreading area and mechanical properties of Sn-9Zn-3Bi solder...In this study,SEM,EDS,XRD and other test methods were used to study the effects of different Ga contents(0~2 wt.%)on microstructure,electrical conductivity,spreading area and mechanical properties of Sn-9Zn-3Bi solder.The results revealed that the microstructure of Sn-Zn-Bi-Ga solder alloy was mainly composed ofβ-Sn,Zn-rich,Bi-rich phase and Sn-Zn eutectic structure.The Ga can significantly improve the wettability of Sn-Zn-Bi on the pure copper,the maximum wetting area was 105.3 mm^2.With the increase of the Ga content the melting point of the solders decreased from 195℃to 177℃.In addition,the Ga element can increase the oxidation resistance of solder.Its conductivity showed a decreasing trend with the gradual increase of the Ga content.With the increased of the Ga content the IMC(Intermetallic Compound)of Sn-Zn-Bi-xGa/Cu is only Cu5Zn8 and its thickness decreased remarkably.展开更多
Low melting point alloy is a potential high-temperature heat transfer medium because of the high thermal conductivity, low solidus temperature and wide range of use temperature. Consequently, we investigated the possi...Low melting point alloy is a potential high-temperature heat transfer medium because of the high thermal conductivity, low solidus temperature and wide range of use temperature. Consequently, we investigated the possibility of using Sn-Bi-Zn-Ga alloys as heat storage and heat transfer material. Moreover, we investigated the microstructure and phase compositions by electron probe micro-analysis (EPMA) and X-ray diffusion (XRD). Results show that the new structures and phases are formed in the alloy matrix with Ga additions, which lead to the improvement of the thermal properties. An extensive thermophysical characterization of the Sn-Bi-Zn-Ga alloys has been performed by differential scanning calorimeter (DSC) analysis. The addition of Ga lowers the peak temperature and increases the heat capacity of the alloys. The thermal expansion of the test alloys increases with increasing temperature and the densities decreases with Ga additions. As the density, specific heat capacity and thermal diffusivity change with temperature and physical state, the thermal conductivity of the alloys first decreases and then increases. These results demonstrate the feasibility of using Sn-Bi-Zn-Ga alloys as the high-temperature heat transfer fluid.展开更多
基金Natural Science Foundation of Shaanxi Provincial Department(No.51974243)Science and Technology Program of Xi'an(Grant No.201805037YD15CG21(16))+1 种基金Natural Science Foundation of Shaanxi Provincial Department(No.2019JZ-31)Natural Science Foundation of Shaanxi Provincial Department(No.2019JQ-284).
文摘In this study,SEM,EDS,XRD and other test methods were used to study the effects of different Ga contents(0~2 wt.%)on microstructure,electrical conductivity,spreading area and mechanical properties of Sn-9Zn-3Bi solder.The results revealed that the microstructure of Sn-Zn-Bi-Ga solder alloy was mainly composed ofβ-Sn,Zn-rich,Bi-rich phase and Sn-Zn eutectic structure.The Ga can significantly improve the wettability of Sn-Zn-Bi on the pure copper,the maximum wetting area was 105.3 mm^2.With the increase of the Ga content the melting point of the solders decreased from 195℃to 177℃.In addition,the Ga element can increase the oxidation resistance of solder.Its conductivity showed a decreasing trend with the gradual increase of the Ga content.With the increased of the Ga content the IMC(Intermetallic Compound)of Sn-Zn-Bi-xGa/Cu is only Cu5Zn8 and its thickness decreased remarkably.
基金Funded by National Key Technology Research&Development Program of China(No.2012BAA05B05)Key Technology Research&Development Program of Hubei(No.2015BAA111)Science and Technology Department of Hubei Province and the Fundamental Research Funds for the Central Universities(No.WUT:2017Ⅱ23GX)
文摘Low melting point alloy is a potential high-temperature heat transfer medium because of the high thermal conductivity, low solidus temperature and wide range of use temperature. Consequently, we investigated the possibility of using Sn-Bi-Zn-Ga alloys as heat storage and heat transfer material. Moreover, we investigated the microstructure and phase compositions by electron probe micro-analysis (EPMA) and X-ray diffusion (XRD). Results show that the new structures and phases are formed in the alloy matrix with Ga additions, which lead to the improvement of the thermal properties. An extensive thermophysical characterization of the Sn-Bi-Zn-Ga alloys has been performed by differential scanning calorimeter (DSC) analysis. The addition of Ga lowers the peak temperature and increases the heat capacity of the alloys. The thermal expansion of the test alloys increases with increasing temperature and the densities decreases with Ga additions. As the density, specific heat capacity and thermal diffusivity change with temperature and physical state, the thermal conductivity of the alloys first decreases and then increases. These results demonstrate the feasibility of using Sn-Bi-Zn-Ga alloys as the high-temperature heat transfer fluid.
