不同本构方程对C71500白铜合金热压缩的拟合分析

Six different mathematical models to predict the hot deformation behavior of C71500 cupronickel alloy

摘要:

在Gleeble-3500热机械模拟机上，获得了C71500白铜合金在1073-1273k和应变速率范围内等温压缩试验的真实应力应变数据(0.01分-10秒-1）。采用Johnson-Cook、Johnson-Cook、Zerilli-Armstrong、Arrhenius、Fields-Backofen-Zhang和Zhou-Guan模型对高温流动应力本构方程进行了回归分析。通过比较精度、相关系数（R）、均方根误差（RMSE）、平均绝对相对误差（AARE）、不确定度个数和计算这些参数所需的时间，评价了六种模型的适用性。根据参数和时间消耗的拟合结果，Zhou-Guan模型是预测C71500合金在不同应变率和温度下变形抗力的最佳模型。研究结果为C71500合金及其它类似的不易冷变形铜合金的性能选择和验证提供了理论依据。

Abstract:

Base on the Gleeble-3500 thermo mechanical simulator, the real stress-strain data of C71500 cupronickel alloy in isothermal compression test were obtained in the temperature range (1073-1273k) and strain rate range (0.01-10s-1). Johnson-Cook, modified Johnson-Cook, modified Zerilli-Armstrong, Arrhenius-type, Fields-Backofen-Zhang and Zhou-Guan models were used to regress the constitutive equation of high temperature flow stress. The applicability of the six models were evaluated by comparing the accuracy, correlation coefficient (R), root mean square error (RMSE), average absolute relative error (AARE), the number of uncertaintyl and the time consuming for calculation of these parameters. According to the fitting results of parameters and time consumption, the Zhou-Guan model is the best for predicting the deformation resistance of C71500 alloy at different strain rates and temperatures. The results provide a theoretical basis for the capability selection and verification of C71500 alloy and other similar copper alloys which are not easily deformed by cold working.