铈对Cu-Zr合金热变形激活能和性能的影响

Effects of Cerium on Hot Deformation Activation Energy and Properties of Cu-Zr Alloy

在Gleeble-1500D热模拟机上对Cu-1%Zr和Cu-1%Zr-0.15%Ce两种合金在变形温度分别为550,650,750,850和900℃,应变速率分别为0.001,0.010,0.100,1.000和10.000 s^(-1)条件下进行等温热压缩实验,分析了Ce对Cu-1%Zr合金热变形激活能的影响。通过透射电子显微镜,研究了合金在时效过程中的析出相和位错组态。结果表明:Cu-1%Zr和Cu-1%Zr-0.15%Ce两种合金具有相似的热压缩变形特征。高Zr和微量Ce的添加使Cu-Zr合金的热变形激活能显著提高。与Cu-1%Zr合金相比,添加0.15%Ce使合金的热变形激活能提高了约34%。添加Ce,使导电率下降了约5%IACS,显微硬度略有提高。通过导电率的变化,计算出时效过程中析出相体积分数,求得550℃时合金的析出动力学方程和导电率方程。

The isothermal hot compression test of Cu-1% Zr and Cu-1% Zr-0. 15% Ce alloys were carried out at elevated temperature of 550,650,750,850,900 ℃ and at the strain rates of 0. 001,0. 010,0. 100,1. 000,10. 000 s^-1,respectively. The effects of Ce on the hot deformation activation energy was analyzed. The precipitates and dislocation configuration of the alloys during aging were investigated by transmission electron microscope. The results showed that the Cu-1% Zr and Cu-1% Zr-0. 15% Ce alloys possessed the similar behavior of hot compression deformation. The hot deformation activation energy increased remarkably due to the addition of high zirconium content and micro alloying of cerium. Compared with Cu-1% Zr alloy,the addition of Ce increased the thermal deformation activation energy of Cu-1% Zr alloy by about 34%. The conductivity was decreased by about 5% IACS and the microhardness was increased by little with addition of 0. 15% Ce. Through the change of conductivity,the volume fraction of precipitates in the aging process was calculated,and the precipitation kinetics equation and the conductivity equation of the alloys were obtained.