Cu-0.8Cr-0.3Zr合金热变形行为及热加工图

Hot deformation behavior and processing maps of Cu-0. 8Cr-0. 3Zr alloy

采用Gleeble-1500D热模拟试验机,研究了Cu-0.8Cr-0.3Zr合金在变形温度为650~950℃、应变速率为0.001~10 s-1、总压缩应变量60%条件下的流变行为,对热变形过程中的组织演变和动态再结晶机制进行了分析,同时分析了该合金的热加工图。结果表明,变形温度越高,应变速率越小,合金越容易发生动态再结晶,且对应的峰值应力也越小。利用逐步回归的方法建立该合金的流变应力方程。绘制了Cu-Cr-Zr合金的热加工图,确定了其热加工时的安全区与失稳区,得出了该合金在实验参数范围内热变形过程的最佳工艺参数：温度范围为850~900℃,应变速率范围为0.1~1 s-1。

Flow stress behavior of Cu-0. 8Cr-0. 3Zr alloy during hot compression deformation at temperature from 650 ℃ to 950 ℃ and strain rate from 0. 001 s- 1to 10 s- 1under the maximum strain of 60% was studied on a Gleeble-1500 D thermal-mechanical simulator. The microstructure evolution of the alloy was observed. The dynamic recrystallization nucleation mechanisms and processing maps of the alloy were established and analyzed. The results show that dynamic recrystallization is easy to occur at high deformation temperature and low strain rate. At the same time,the corresponding peak stress is lower. The flow stress constitutive equation is established by stepwise regression analysis. The safety and instability zones are recognized by the processing maps in hot deformation. The optimum processing parameters of hot deformation for Cu-0. 8Cr-0. 3Zr alloy in the range of this experiment are at temperature of 850-900 ℃ and strain rate of0. 1-1 s- 1.