超轻镁锂合金LZ91热变形行为探究：本构方程及热加工图

本文以挤压态Mg-9Li-1Zn镁锂合金为材料在Gleeble3500热模拟实验机上做热压缩变形实验，变形温度范围为150℃-350℃，应变速率范围为0.001s-1-10s-1。基于所采集实验数据绘制流变应力应变曲线，建立了双曲线正弦函数的本构方程及真应变为0.916时热加工图，结合变形后微观组织观测分析了动态再结晶的产生情况，表明了适宜加工的安全区域和在加工中应该避免的失稳区域，预测温度范围为250-300℃，应变速率0.01s-1时为较理想的变形参数，峰值耗散系数值大于38.55%，热变形激活能Q=112.066kJ/mol，应力指数n=3.60273。

Research on the hot deformation behavior of ultralight magnesium-lithium alloy LZ91: Constitutive equation and processing map

In this paper, the hot compression deformation tests were carried out on a Gleeble 3500 thermal simulator using extruded Mg-9Li-1Zn magnesium-lithium alloy. The deformation temperature was 150 °C-350 °C, and the strain rate ranged from 0.001 s_^-1 to 10 s_^-1. The rheological stress-strain curve and constitutive equation of the hyperbolic sine function were established based on experiment data. The processing maps was developed for the samples deformed to strain of 0.916. The dynamic recrystallization is analyzed by the microstructure observation after hot deformation. Indicate safe areas suitable for processing and areas of instability that should be avoided during processing. The ideal deformation condition parameters are predicted to be in the range of 250-300 °C and the strain rate is 0.01 s_^-1, in which domain with a peak dissipation efficiency greater than 38.55%, and the activation energy for plastic deformation Q is equal to 112.066 kJ/mol and stress exponent equals 3.60273.