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用重力浇注法制得AM60和AM60+1%Y两种镁合金,采用等温热处理法制备半固态组织;分析了Y元素对AM60镁合金铸态组织的影响,研究了等温温度、等温时间及稀土元素Y对AM60镁合金半固态组织演变的作用机理。结果表明:稀土元素Y的添加可以减小AM60的铸态晶粒尺寸;Y与Al结合,形成了高熔点的Al2Y相;而且Y部分置换β-Mg_(17)Al_(12)中的Mg原子,形成(Mg,Y)_(17)Al_(12)相。经过等温处理,AM60和含YAM60镁合金都可以获得良好的半固态组织,AM60+1%Y的等温温度高于AM60镁合金,固相颗粒尺寸约为15μm,远小于AM60镁合金,这主要是由于Al_2Y相在高温下的钉扎和抑制作用。
The semi-solid microstructures of AM60 and AM60 + 1% Y were prepared by gravity casting. The semi-solid microstructure was prepared by isothermal heat treatment. The effect of Y element on the as-cast microstructure of AM60 magnesium alloy was analyzed. The isothermal temperature, isothermal time and Mechanism of Rare Earth Element Y on Semi - solid Microstructure Evolution of AM60 Magnesium Alloy. The results show that the addition of rare earth element Y can reduce the as-cast grain size of AM60; Y combines with Al to form a high-melting Al2Y phase; and Y partially displaces Mg atoms in β-Mg 17 Al 12 (Mg, Y) _ (17) Al_ (12) phase is formed. After isothermal treatment, AM60 and YAM60 containing magnesium alloy can obtain good semi-solid microstructure. The isothermal temperature of AM60 + 1% Y is higher than that of AM60 magnesium alloy. The size of solid phase is about 15μm, which is much smaller than that of AM60 magnesium alloy. Due to pinning and inhibition of Al 2 Y phase at high temperatures.