Mg-Gd-Y-Zr合金凝固组织特征参数模拟及在航天构件上的应用

Simulation on Characteristic Parameters of Solidification Microstructure of Mg-Gd-Y-Zr Alloy and Its Application to Aerospace Components

基于Mg-Gd-Y-Zr合金凝固组织与工艺条件的关系,模拟了典型航天构件组织特征参数的分布。浇铸了阶梯形铸件,并采用热电偶测量了阶梯形铸件不同厚度处在凝固过程中的温度变化。通过观察凝固组织,并与冷却条件比对,获得了凝固组织中晶粒尺寸和第二相体积分数与冷却速率的定量关系。采用ProCAST~?软件模拟了典型航天构件的凝固过程,获得了凝固过程中构件不同部位的冷却速率。利用实验获得的定量关系,模拟得到了典型航天构件上晶粒尺寸和第二相体积分数的分布。

The distributions of characteristic parameters about the solidification microstructure of a typical aerospace component are simulated based on the relationships between the solidification microstructure and processing conditions of Mg-Gd-Y-Zr alloy.In this study,castings with steps are produced,and thermocouples are employed to record the temperature variation at different thicknesses in the castings.The effects of the cooling rate on the grain size and the fraction of the secondary phase are quantitatively determined by studying the solidification microstructure under different cooling conditions.ProCAST software is utilized to simulate the solidification process of the typical aerospace component,and the distributions of cooling rates are obtained.The distributions of grain sizes and fractions of the secondary phase are acquired based on the cooling rate obtained by the simulation.