摘要
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 AM60 and AM60 ＋ 1% Y magnesium alloys were prepared by gravity casting, and the semisolid microstructure was prepared by isothermal treatment. The effects of Y on as-cast microstructure of AM60 magnesium alloy were analyzed, and the mechanism of isothermal temperature, time and Y element on the evolution of semisolid microstructure of AM60 magnesium alloy was investigated. The results show that adding Y in AM60 alloy can minimize the as-cast grain size. Y and AI elements form AI2Y phase with high melting point, and Y substitutes partial Mg atoms in β-Mg,TAl12 and forms （Mg, RE）17TAl12 phase. After isothermal treatment, the AM60 and AM60＋1%Y alloys can obtain fine semisolid microstructure. The isothermal temperature of AM60＋1%Y alloy is higher than that of AM60 magnesium alloy, and the solid particles size of semisolid AM60＋1%Y alloy is about 15 μm, which is less than that of AM60 magnesium alloy. This is mainly due to the pinning and inhibition of A12Y phase at high temperature.
出处
《热加工工艺》
CSCD
北大核心
2017年第15期109-111,115,共4页
Hot Working Technology
