Abstract: The hot compression of as-cast alloy Ni68Cu28Al is simulated by Gleeble 3500 thermal simulator at defonnation temperature 1 000 ~ 1 150 °C with strain rate of 0.01 ~ 10 s^-1. The flow stress curves of alloy at different conditions are analyzed, the constitutive equation describing the high temperature compression deformation of alloy is established, the constitutive equation is applied to the finite element analysis software DEFORM 3D,and the hot compression process of the alloy is numerically simulated to analyze the changes of strain rate field, strain field and temperature field inside the workpiece. The results show that the hardening effect of as-cast Ni68Cu28Al alloy is very strong during deformation, and the softening effect caused by dynamic recovery and dynamic recrystallization is not obvious, the alloy does not recrystallize completely during deformation,the hot compression process of the alloy has obvious non-uniformity of deformation. Comprehensively considering, the best processing temperature of as-cast Ni68Cu28Al alloy is controlled at 1 000 - 1 100 °C , and the strain rate is about 0. 01 s^-1.

摘要： 利用Gleeble3500热模拟试验机，在变形温度1000~1150 ℃，应变速率为0.01~10 s^-1时对铸态Ni68Cu28Al合金进行热压缩模拟。分析了合金在不同条件下的流变应力曲线；建立了描述该合金高温压缩变形的本构方程；将本构方程应用于有限元分析软件DEFORM 3D中，并对合金热压缩过程进行数值模拟，分析工件内部的应变速率场、应变场和温度场变化。结果表明，铸态Ni68Cu28Al合金变形过程中的硬化效果非常大，动态回复和动态再结晶引起的软化作用不明显;变形过程材料未完全再结晶;合金热压缩过程具有明显的变形不均匀性。综合考虑，铸态Ni68Cu28Al 合金最佳加工温度控制在1000~1100 ℃，应变速率0.01 s^-1左右。