【摘要】 制备了不同成分的Al-xSi-yGe三元钎料合金（x=4～12,y=10～40，质量分数），研究了Si和Ge对钎料微观结构和熔化特性的影响。基于二元合金生成焓模型（Miedema model）、熵焓模型（Tanaka model）和Toop方程建立了热力学计算模型，分析钎料的相形成机理，为钎料成分优化和分析钎料与母材的冶金反应过程提供基础。结果表明，Al-Si-Ge主要由Al-Ge共晶相、Al-Si共晶相和初晶Si组成，Ge的增加会促进初晶Si的析出。Ge为钎料的主要降熔元素，随着Ge含量从10%增加至40%，变化钎料固相线保持不变，液相线从567.65℃降低至499.96℃。随着钎料中Ge添加量的增加，共晶Si相中的Ge含量增加，热重分析曲线中Al-Si共晶反应的吸热峰变得更平滑，Al-Si共晶温度降低。添加Ge可以降低Al-Si合金体系的自由能，自由能的最低点位于Al-Ge侧。成分接近纯Ge的共晶Ge相最有可能出现在钎料中，而成分接近纯Si的共晶Si相最不可能出现。热力学计算结果与实验结果一致。更多还原

【Abstract】 A series of Al-xSi-yGe filler metals(x=4 – 12 and y=10 – 40,wt%) were prepared,and the effect of Si and Ge on microstructure and melting characteristics of filler metals was studied.The thermodynamic model of Al-Si-Ge ternary alloy was established to analyze the phase formation mechanism of filler metals based on Miedema model,Tanaka model,and Toop equation.This research provided a basis for the composition optimization of filler metals and the analysis of metallurgical reaction process between filler metals and base materials.Results show that Al-Si-Ge alloy is composed of Al-Ge eutectic phase,Al-Si eutectic phase,and primary Si.Ge addition promotes the precipitation of primary Si.Ge is the main melting point depressant element of filler metals.With the increase in Ge content from 10wt% to 40wt%,the solid phase line of filler metals remains unchanged,whereas the liquidus temperature decreases from 567.65 ℃ to 499.96 ℃.With the increase in Ge content of filler metal,Ge content in eutectic Si phase is increased,the endothermic peak of Al-Si eutectic reaction according to thermogravimetry curve becomes smoother,and Al-Si eutectic temperature is decreased.Ge addition can reduce the free energy of Al-Si alloy system.The lowest point of free energy is located on Al-Ge side.The eutectic Ge phase with the composition similar to pure Ge composition is the most likely to appear in the microstructure of filler metals,whereas the eutectic Si phase with the composition similar to pure Si composition is the least likely to appear.The thermodynamic calculation results are consistent with the experiment results.更多还原