(1. 中南大学 材料科学与工程学院，长沙 410083;
2. 湖南人文科技学院 机电工程系，娄底 417000;
3. 北京有色金属研究总院，北京 100088;
4. 湖南文昌科技有限公司，娄底 417000)
摘 要: 采用基于CALPHAD法的热力学模拟对Al-xSi-yCu-zMg半固态高硅铝合金进行合金成分的优化设计。实验以元素Si、Cu、Mg为因变量，对Al-Si-Cu-Mg四元高硅铝合金进行热力学模拟，并用DSC测试分析验证模拟结果，对合金成分进行了优化。结果表明:Cu、Mg是合金设计的两个关键元素，能显著影响液相体积分数对温度的敏感度以及温度间隔，而Si元素对其影响较小。结合半固态合金热力学设计判据，Al-17Si-4.5Cu-1.5Mg、Al-17Si-5Cu-1Mg和Al-17Si-4Cu-2Mg是较理想的半固态触变成形用高硅铝合金。
关键字: 高硅铝合金;CALPHAD方法;半固态触变成形
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Department of Mechanical and Electrical Engineering,
Hunan University of Humanities Science and Technology, Loudi 417000, China;
3. Beijing General Research Institute for Nonferrous Metals, Beijing 100088, China;
4.Hunan Wenchang Technology Company Limited, Loudi 417000, China）
Abstract:The thermodynamic simulation based on CALPHAD method was applied to optimize the high silicon aluminum alloys Al-xSi-yCu-zMg for semi-solid thixoforming. This simulation was performed with three parameters Si, Cu and Mg, and the results were analyzed and compared with the DSC test, and then, the semi-solid alloys were optimized. The results show that Cu and Mg are two key elements for alloys design and can notably affect liquid volume fraction vs temperature sensitivity and temperature interval, while Si has little effect on these two parameters. Considering the criterion of alloys design, some new optimal alloys for semi-solid processing are available:Al-17Si-4.5Cu-1.5Mg, Al-17Si-5Cu-1Mg and Al-17Si-4Cu-2Mg.
Key words: high-silicon aluminum alloy; CALPHAD method; semi-solid thixoforming
