99.992%高纯多晶铝热压缩流变应力特征

Flow Stress Feature of 99.992% Aluminum under Hot Compression Deformation

采用 Gleeble- 15 0 0热模拟机进行高温等温压缩试验 ,研究了 99.992 %高纯铝在变形温度为 2 6 0～ 5 0 0℃、应变速率为 0 .0 0 2～ 2 s- 1条件下的流变应力特征。结果表明 ,低温 (T=2 6 0℃ )、高应变速率 (ε=2 s- 1 )时其流变应力达到峰值后趋于稳定 ,表现出动态回复特征 ;而在较高温度 (T≥ 4 0 0℃ )及较低应变速率 (ε≤ 0 .2 s- 1 )下流变应力达到峰值后随应变的增加而不断下降 ,表现出动态再结晶特征。用 Zenner- Hollomon参数的幂函数形式能较好的描述 99.992

The flow stress feature of 99.992% high purity aluminum was studied at temperatures ranging from 260~500℃ and strain rates of 0.002~2s^(-1) on Gleeble-1500 hot simulator. The results show that the flow stress of (99.992%) aluminum tends to be constant after a peak value at lower temperature(T=260℃) and higher strain rate(= 2s^(-1)),which is typical dynamic recovery curve; At higher temperatures (T≥400℃) and lower strain rates(≤0.2s^(-1)), the flow stress decreased after a peak value with increasing strain, which showing dynamic recrystallization. The flow stress of 99.992% aluminum during hot deformation can be presented by a Zenner-Hollomon parameter in the power-type equation.