冷却速度对含稀土元素Nd的共晶成分镁铝合金组织的影响

Influence of Cooling Velocity on Solidification Structure of Eutectic Component Mg-Al Alloy Containing Rare Earth Nd

模拟AZ91镁合金半固态液相凝固后期的成分,分析了共晶成分镁铝合金添加1.0%wt含量的稀土元素Nd后,不同冷却速度下的凝固组织。结果表明:采用石墨型浇注得到的凝固组织相较砂型浇注的明显细小,其中树枝状初晶α相对发达,共晶组织相对致密,在砂型浇注的凝固组织中出现了高Al含量的树枝状初晶α相。

In this article, components of semi-solid AZ91 magnesium alloy liquid during the latter term of solidification have been simulated, and the changes of solidification microstructures at different cooling velocity have been analyzed when rare earth metal Nd of 1.0% wt was added to Mg- Al alloy. The results show that, solidification microstructures adopting graphite mould casting was obviously small compared with sand mould casting; tree crystal αwas relatively giant and eutectic microstructure was relatively densified; there was tree crystal αcontaining high Al at sand mould casting.