压铸态AZ91D镁合金热压缩变形流变应力研究

Flow Stress of Die-Cast AZ91D Magnesium Alloy under Hot Compression Deformation

在应变速率为0.01～10 s-1、变形温度250～450℃的条件下,采用Geeble-1500D热模拟机对压铸态AZ91D镁合金进行热压缩变形试验,得到并分析了该材料在不同变形条件下的流变曲线。采用数理统计的方法对实验数据进行处理,建立了用Zener-Hollomom参数描述的该材料的高温塑性变形本构方程为=1.41×1012[sinh(0.014σ)]5.295exp(–159 449.509/RT),采用双曲正弦函数确定了该材料的变形激活能Q=159.45 kJ·mol-1;与重力铸造态AZ91D镁合金比较显示,其流变应力和变形激活能更低。

Hot compression tests of die-cast AZ91D magnesium alloy were performed on Gleeblle-1500D at strain rates ranging in 0.01-10 s^-1 and deformation temperatures ranging in 250-450 ℃. The constitutive equation, ε =1.41-1012 [sinh（0.014o）]5295exp （-159 449.509/RT）, which is described by Zener-Hollomom parameters for hot compression deformation of die-cast AZ91D magnesium alloy was established. Compared to gravity cast AZ91D magnesium alloy, the deformation activation energy of die-cast AZ91D magnesium alloy, Q=159.45 kJ·mol^-1, determined by hyperbolic sine function is lower.