Y对Cu-Cr-Zr合金高温热变形行为的影响

Effects of Y addition on hot deformation behavior of Cu-Cr-Zr alloy at elevated temperature

利用Gleeble-1500D热模拟试验机对Cu-Cr-Zr和Cu-Cr-Zr-Y合金,进行高温等温压缩试验,研究了在变形温度为650~850℃、应变速率为0.001~10 s-1条件下两种合金的流变应力的变化规律,测定了真应力一应变曲线,从流变应力、应变速率和温度的相关性,得出了该合金热压缩变形时的热变形激活能Q和本构方程,并利用光学显微镜分析了合金在热压缩过程中的组织演变及动态再结晶机制。结果表明:稀土元素Y的加入细化了微观组织,提高了Cu-Cr-Zr合金的动态再结晶体积分数,并且大幅降低了合金的热变形激活能Q,改善了其热加工性能。

Flow stress change rules and deformation behavior of Cu-Cr-Zr and Cu-Cr-Zr-Y alloys during hot compression deformation were studied by isothermal compression test at a Gleeble-1500D thermal-mechanical simulator at elevated temperature ranging from 650 ℃ to 850 ℃ and at the strain rate from 0.001 s-1to 10 s-1.On the basis of the above experimental results,the hot deformation activation energy Q was derived from the correlativity of flow stress,strain rate and temperature,respectively.And the constitutive equations of them were also established,which characterize the relationship among the flow stress,the strain rate and the testing temperature during the isothermal compression plastic deformation.The microstructure evolution and dynamic recrystallization nucleation mechanisms of the alloy during compression deformation were analyzed with an optical microscope.Because of addition of Y,the recrystallization grain size and the hot deformation activation energy Q of Cu-Cr-Zr alloy decrease,the recrystallization volume fraction increases,and the hot working performance improves.