从熔融钎料与母材的相关系和相反应(phase relation and phase reaction)出发,讨论了无铅钎料在铜上铺展率和钎焊性低下的原因,认为是其间过度和过于快速的金属间化合物生长所致。分析了提高无铅钎料本身在铜上铺展率的困难,提出解决无...从熔融钎料与母材的相关系和相反应(phase relation and phase reaction)出发,讨论了无铅钎料在铜上铺展率和钎焊性低下的原因,认为是其间过度和过于快速的金属间化合物生长所致。分析了提高无铅钎料本身在铜上铺展率的困难,提出解决无铅钎焊的途径主要是开发有效的钎剂和进行基板母材表面的改性。展开更多
The effect of Sb content on the properties of Sn-Bi solders was studied. The nonequilibrium melting behaviors of a series of Sn-Bi-Sb solders were examined by differential scanning calorimetry （DSC）. The spreading t...The effect of Sb content on the properties of Sn-Bi solders was studied. The nonequilibrium melting behaviors of a series of Sn-Bi-Sb solders were examined by differential scanning calorimetry （DSC）. The spreading test was carried out to characterize the wettability of Sn-Bi-Sb solders on Cu substrate. The mechanical properties of the solders/Cu joints were evaluated. The results show that the ternary alloy solders contain eutectic structure resulting from quasi-peritetic reaction. With the increase of Sb content, the amount of the eutectic structure increases. At a heating rate of 5 ℃/min, Sn-Bi-Sb alloys exhibit a higher melting point and a wider melting range. A small amount of Sb has an impact on the wettability of Sn-Bi solders. The reaction layers form during spreading process. Sb is detected in the reaction layer while Bi is not detected. The total thickness of reaction layer between solder and Cu increases with the increase of the Sb content. The shear strength of the Sn-Bi-Sb solders increases as the Sb content increases.展开更多
The effects of Ni content on the microstructure and the wetting behavior of Sn-9Zn-xNi solders on Al and Cu substrates, as well as the mechanical properties and electrochemical corrosion behavior of Al/Sn-9Zn-xNi/Cu s...The effects of Ni content on the microstructure and the wetting behavior of Sn-9Zn-xNi solders on Al and Cu substrates, as well as the mechanical properties and electrochemical corrosion behavior of Al/Sn-9Zn-xNi/Cu solder joints, were investigated. The microstructure of Sn-gZn-xNi revealed that tiny Zn and coarsened Ni5Zn21 phases dispersed in theβ-Sn matrix. The wettability of Sn-9Zn-xNi solders on Al substrate was much better than that on Cu substrate. With increasing Ni content, the wettability on Cu substrate was slightly improved but became worse on Al substrate. In the Al/Sn-9Zn-xNi/Cu joints, an Al4.2Cu3.2Zn0.7 intermetallic compound （IMC） layer formed at the Sn-gZn-xNi/Cu interfaces, while an Al-Zn-Sn solid solution layer formed at the Sn-9Zn-xNi/Al interface. The mixed compounds of Ni3Sna and Al3Ni dispersed in the solder matrix and coarsened with increasing Ni content, thus leading to a reduction in shear strength of the Al/Sn-9Zn- xNi/Cu joints. Al particles were segregated at both interfaces in the solder joints. The corrosion potentials of Sn-9Zn-xNi solders continuously increased with increasing Ni content. The Al/Sn-9Zn-0.25Ni/Cu joint was found to have the best electrochemical corrosion resistance in 5% NaCl solution.展开更多
The Sn9Zn eutectic alloy is the nontoxic lead-free solders alternative having a melting temperature which is closest to that of the eutectic SnPb alloy. In order to improve the properties of SnZn lead-free solders, 0-...The Sn9Zn eutectic alloy is the nontoxic lead-free solders alternative having a melting temperature which is closest to that of the eutectic SnPb alloy. In order to improve the properties of SnZn lead-free solders, 0-0.5 wt.% of rare earth Er was added to the base alloys, and the microstructures were studied. Results showed that the addition of rare earth Er could enhance the wettability of SnZn solders, with 0.08%Er addition, the spreading area gavc an 19.1% increase. And based on the mechanical testing, it was found that the tensile force and shear force of SnZn-xEr solder joints could be improved significantly. Moreover, the oxidation resistance of SnZn0.08Er solder was better than that of SnZn solder, in addition, it was found that trace amounts of rare earth Er could refine the microstructures of SnZn solders, espe- cially for Zn-rich phases, and excessive amount of rare earth Er led to a coarse microstructure.展开更多
Extensive testing was carried out to study the effects of rare earth Ce doping on the properties of SnAgCu solder alloys.The addition of 0.03%(mass fraction) rare earth Ce into SnAgCu solder may improve its mechanical...Extensive testing was carried out to study the effects of rare earth Ce doping on the properties of SnAgCu solder alloys.The addition of 0.03%(mass fraction) rare earth Ce into SnAgCu solder may improve its mechanical properties,but slightly lower its melting temperature.The tensile creep behavior of bulk SnAgCuCe solders was reported and compared with SnAgCu solders.It is found that SnAgCuCe solders show higher creep resistance than SnAgCu alloys.Moreover,Dorn model and Garofalo model are successfully used to describe the creep behavior of SnAgCu and SnAgCuCe alloys.The parameters of the two creep constitutive equations for SnAgCu and SnAgCuCe solders are determined from separated constitutive relations and experimental results.Nonlinear least-squares fitting is selected to determine the model constants.The experimental data of the stress-creep strain rate curves are in good agreement with the theoretical ones.展开更多
文摘从熔融钎料与母材的相关系和相反应(phase relation and phase reaction)出发,讨论了无铅钎料在铜上铺展率和钎焊性低下的原因,认为是其间过度和过于快速的金属间化合物生长所致。分析了提高无铅钎料本身在铜上铺展率的困难,提出解决无铅钎焊的途径主要是开发有效的钎剂和进行基板母材表面的改性。
基金Project(51004039)supported by the National Natural Science Foundation of ChinaProject(2012713)supported by the Cooperation Promoting Foundation in Science and Technology of Shaoxing City,China
文摘The effect of Sb content on the properties of Sn-Bi solders was studied. The nonequilibrium melting behaviors of a series of Sn-Bi-Sb solders were examined by differential scanning calorimetry （DSC）. The spreading test was carried out to characterize the wettability of Sn-Bi-Sb solders on Cu substrate. The mechanical properties of the solders/Cu joints were evaluated. The results show that the ternary alloy solders contain eutectic structure resulting from quasi-peritetic reaction. With the increase of Sb content, the amount of the eutectic structure increases. At a heating rate of 5 ℃/min, Sn-Bi-Sb alloys exhibit a higher melting point and a wider melting range. A small amount of Sb has an impact on the wettability of Sn-Bi solders. The reaction layers form during spreading process. Sb is detected in the reaction layer while Bi is not detected. The total thickness of reaction layer between solder and Cu increases with the increase of the Sb content. The shear strength of the Sn-Bi-Sb solders increases as the Sb content increases.
基金supported by the National Natural Science Foundation of China (Nos. U0734006 and 51171036)
文摘The effects of Ni content on the microstructure and the wetting behavior of Sn-9Zn-xNi solders on Al and Cu substrates, as well as the mechanical properties and electrochemical corrosion behavior of Al/Sn-9Zn-xNi/Cu solder joints, were investigated. The microstructure of Sn-gZn-xNi revealed that tiny Zn and coarsened Ni5Zn21 phases dispersed in theβ-Sn matrix. The wettability of Sn-9Zn-xNi solders on Al substrate was much better than that on Cu substrate. With increasing Ni content, the wettability on Cu substrate was slightly improved but became worse on Al substrate. In the Al/Sn-9Zn-xNi/Cu joints, an Al4.2Cu3.2Zn0.7 intermetallic compound （IMC） layer formed at the Sn-gZn-xNi/Cu interfaces, while an Al-Zn-Sn solid solution layer formed at the Sn-9Zn-xNi/Al interface. The mixed compounds of Ni3Sna and Al3Ni dispersed in the solder matrix and coarsened with increasing Ni content, thus leading to a reduction in shear strength of the Al/Sn-9Zn- xNi/Cu joints. Al particles were segregated at both interfaces in the solder joints. The corrosion potentials of Sn-9Zn-xNi solders continuously increased with increasing Ni content. The Al/Sn-9Zn-0.25Ni/Cu joint was found to have the best electrochemical corrosion resistance in 5% NaCl solution.
基金Project supported by Provincial Key Lab of Advanced Welding Technology Foundation(JSAWS-11-03)the Xuzhou Normal University Foundation(11XLR16)Natural Science Foundation of Jiangsu Province(BK2012144)
文摘The Sn9Zn eutectic alloy is the nontoxic lead-free solders alternative having a melting temperature which is closest to that of the eutectic SnPb alloy. In order to improve the properties of SnZn lead-free solders, 0-0.5 wt.% of rare earth Er was added to the base alloys, and the microstructures were studied. Results showed that the addition of rare earth Er could enhance the wettability of SnZn solders, with 0.08%Er addition, the spreading area gavc an 19.1% increase. And based on the mechanical testing, it was found that the tensile force and shear force of SnZn-xEr solder joints could be improved significantly. Moreover, the oxidation resistance of SnZn0.08Er solder was better than that of SnZn solder, in addition, it was found that trace amounts of rare earth Er could refine the microstructures of SnZn solders, espe- cially for Zn-rich phases, and excessive amount of rare earth Er led to a coarse microstructure.
基金Project(BCXJ09-07) supported by Doctoral Dissertation Innovation and Excellence Producing Foundation of Nanjing University of Aeronautics and Astronautics,ChinaProject(CX07B_087z) supported by the Jiangsu General Colleges and Universities Postgraduate Scientific Research Innovative Plan,China
文摘Extensive testing was carried out to study the effects of rare earth Ce doping on the properties of SnAgCu solder alloys.The addition of 0.03%(mass fraction) rare earth Ce into SnAgCu solder may improve its mechanical properties,but slightly lower its melting temperature.The tensile creep behavior of bulk SnAgCuCe solders was reported and compared with SnAgCu solders.It is found that SnAgCuCe solders show higher creep resistance than SnAgCu alloys.Moreover,Dorn model and Garofalo model are successfully used to describe the creep behavior of SnAgCu and SnAgCuCe alloys.The parameters of the two creep constitutive equations for SnAgCu and SnAgCuCe solders are determined from separated constitutive relations and experimental results.Nonlinear least-squares fitting is selected to determine the model constants.The experimental data of the stress-creep strain rate curves are in good agreement with the theoretical ones.
