Cu-0.5Cr-0.1Zr合金的热压缩变形行为

通过热压缩试验研究了Cu-0.5Cr-0.1Zr合金在600~750 ℃/0.001~1.0 s^-1时的热变形行为。结果表明,Cu-0.5Cr-0.1Zr合金的高温流变应力,动态再结晶临界值和动态再结晶软化效应与变形温度和应变速率密切相关。利用Arrhenius方程计算了Cu-0.5Cr-0.1Zr合金的热激活能Q和Z参数,分别为244.94 kJ/mol、Z=ε·exp(244.94×10³/RT)。采用3种方法进行了动态再结晶临界值的计算,结果证明Poliak-Jonas准则具有最高的精度,并建立了动态再结晶临界值的本构方程。利用动态再结晶的净软化效应η值,讨论了热变形过程中动态再结晶的软化行为。最后,建立了Cu-0.5Cr-0.1Zr合金的热加工图,确定最佳的热加工参数为680~750 ℃,0.001~0.03 s^-1,并详细介绍了功率耗散系数与动态再结晶晶粒尺寸之间的关系。

Hot compression deformation behavior of Cu-0.5Cr-0.1Zr alloy

Hot deformation behavior of the Cu-0.5Cr-0.1Zr alloy at 600-750 ℃/0.001-1.0 s^-1 was studied by hot compression test. The results show that the high temperature flow stress, dynamic recrystallization critical values and dynamic recrystallization softening behavior of the Cu-0.5Cr-0.1Zr alloy were closely related to the deformation temperature and strain rate. The thermal activation energy Q and Zener-Hollomon parameter of the Cu-0.5Cr-0.1Zr alloy were calculated using the Arrhenius equation, which are 244.94 kJ/mol and Z=ε·exp(244.94×10³/RT), respectively. Also, the calculated results of the critical values of dynamic recrystallization by using three methods prove that the Poliak-Jonas criterion has the highest accuracy, and based on which the constitutive equation for the critical values of dynamic recrystallization was established. Furthermore, using the net softening effect η values of dynamic recrystallization, the softening behavior of dynamic recrystallization during hot deformation is discussed. Finally, the processing map of the Cu-0.5Cr-0.1Zr alloy is established, from which the best thermal processing parameter is determined to be 680-750 ℃ and 0.03-0.001 s^-1, and the relationship between power dissipation coefficient and dynamic recrystallized grain size is introduced in detail.