LD7铝合金热变形研究

Study on Hot Deformation of LD7 Aluminum Alloy

在Gleeble-1500热模拟机上对LD7铝合金进行等温热变形实验,变形温度为300-500℃,应变速率为 0．01-10s-1,研究其热变形的流变应力行为、显微组织及软化机制。结果表明LD7铝合金真应力-真应变曲线表现出动态回复特征,在应变速率ε=1．0s-1,变形温度高于420℃时,应力出现锯齿波动,表现出不连续动态再结晶特征。合金在压缩过程中主要软化机制为动态回复,同时也存在动态再结晶。变形后晶粒尺寸随变形温度升高而增大,随变形速率增加而减小。

The flow stress behavior of LD7 aluminum alloy, and .softening mechanism during hot deformation conditions was studied by isothermal hot compression on Gleeble-1500. The deformation temperature range from 300℃ to 500℃ and the strain rate range from 0. 01s^-1 to 10s^-1. The experimental results indicated that the flow stress shows dynamic recover, when the strain rate is 1. 0s^-1 and the deformation temperature is more than 420℃, the flow stress saw tooth fluctuates, showing discontinuous dynamic recrystallization. The most important softening mechanism is dynamic recover during the deformation, dynamic recrystallization also be found. The grain size after deformation increases with the increase of the temperature and declines with the increase of the strain rate.