铂的热变形行为及显微组织演变

Hot Deformation Behavior and Microstructure Evolution of Platinum

摘要:

通过热压缩实验研究了铂的热变形行为，通过对应力-应变曲线的分析，构建了预测铂流动特性的本构方程。利用本构方程，计算了不同温度和应变速率下铂在热加工过程中的峰值应力。结果表明：预测值与实验结果非常吻合。电子背散射衍射分析揭示了安全加工区域内不同条件下的热变形机制。优选的加工参数为变形温度860~910 K，应变速率0.01~0.1 s^-1。在高应变速率下观察到的不连续屈服是由于晶界上可动位错的增殖和运动造成的。

Abstract:

The hot deformation behavior of platinum was investigated through hot compression experiments. A constitutive equation for the prediction of the flow behavior of platinum was derived from analysis of stress-strain curves. Using the constitutive equation, the peak stress of platinum during hot working was calculated across varying temperatures and strain rates. Results show that the predicted values have strong agreement with experimental results. Electron backscatter diffraction analysis further reveals the thermal deformation mechanisms under distinct conditions within the safe processing region. The optimal processing parameters are identified as deformation temperatures of 860–910 K and strain rates of 0.01–0.1 s^-1. Discontinuous yielding observed at elevated strain rates is attributed to the multiplication and movement of the mobile dislocations at grain boundaries.