稀土Er对A356合金组织与性能的影响

Effects of Er Addition on the Microstructure and Mechanical Properties of A356 Aluminum Alloys

利用金相显微镜、扫描电镜和拉伸试验机研究了Er元素对A356合金组织与性能的影响,并分析了其变质机制。结果表明,Er元素可以改善与共晶Si的形貌,得到短杆状共晶Si。当Er含量为0.3%时合金的力学性能最好。经T6热处理后,合金抗拉强度提高了31.2%,伸长率提高了233%。

The effects of Er additions on the microstructure of eutectic Si was investigated using optical microscopy（OM）,scanning electron microscopy（SEM）and tensile testing.The modification mechanism was analyzed.The results show that Er can modify the shape of eutectic Si from coarse plate like to fine rod structure with full modification.The optimal mechanical properties of the A356 alloy can be obtained with 0.3% Er addition.After T6 treatment,the tensile strength and elongation of the A356 alloy are increased by 31.2% and 233%,respectively.