Er、Sc微合金化对WAAM Al-7Si-0.6Mg合金组织与性能的影响

Effects of Er,Sc Addition on Microstructure and Properties of WAAM Al-7Si-0.6Mg Alloy

通过金相显微镜、扫描电子显微镜、室温及高温拉伸试验研究了Er、Sc微合金化对电弧增材制造Al-7Si-0.6Mg成形合金组织及性能的影响。结果表明,Er的添加导致直接沉积态成形合金枝晶干变短、枝晶变细;Sc的添加导致直接沉积态成形合金α-Al枝晶尺寸变短,趋于等轴,经过T6热处理后,微观组织差异消除。Er、Sc的添加提高了200、250℃电弧增材制造Al-7Si-0.6Mg成形合金的高温性能稳定性,且Sc的效果优于Er。

The effects of Er and Sc addition on the microstructure and properties of Al-7Si-0.6Mg fabricated alloy by wire arc additive manufacturing(WAAM)were studied by metallographic microscope,scanning electron microscope,room temperature and high temperature tensile tests.The results show that the addition of Er leads to the shortening of the dendrites and the thinning of the dendrites in the as-deposited alloy,and the addition of Sc leads to the shortening of the size of theα-Al dendrites of the as-deposited alloy,which tends to be equiaxed.After T6 heat treatment,the microstructure differences are eliminated.The addition of Er,Sc can improve the high temperature performance stability of WAAM Al-7Si-0.6Mg alloys at 200 and 250°C,and the effect of Sc is better than that of Er.