基于摩擦-温度双修正的Al_(2)O_(3)/Cu烧结坯热变形行为

Hot Deformation Behavior of Al_(2)O_(3)/Cu Sintered Billet Based on Friction-temperature Double Correction

为精准描述热变形行为,对Al_(2)O_(3)弥散铜烧结坯流变应力进行修正。对Al_(2)O_(3)弥散铜烧结坯进行热模拟试验,获得变形温度为923~1223 K、应变速率为0.01~10 s^(-1)条件下的流变应力曲线,根据摩擦、温度修正原理进行流变应力修正,建立基于双曲正弦本构关系Arrhenius流动应力模型的本构方程并进行误差分析。结果表明,随着变形温度降低和应变速率升高,摩擦和温升效应对流变应力的影响逐渐显著。通过数据拟合建立了各影响因素关于摩擦和温升效应修正的定量描述。基于修正后的流变应力数据建立本构方程,平均误差从修正前的9.11%降至5.20%,相关系数由0.95735提高至0.99756,修正后的本构方程更为精准。

The flow stress of Al_(2)O_(3) dispersed copper sintered billet was modified to accurately describe the thermal deformation behavior.The thermal modeling test was conducted to obtain flow stress curve under the condition of deformation temperature of 923 K~1223 K and strain rate of 0.01 s^(−1)~10 s^(−1).The flow stress was modified by friction and temperature correction principle,and the constitutive equations of Arrhenius flow stress model based on the hyperbolic sine constitutive relation were established and the error analysis was carried out.The results indicate that the effects of friction and temperature rise on the flow stress are gradually significant with the decrease of deformation temperature and the increase of strain rate.The quantitative descriptions of each influencing factor on correction of friction and temperature rise effects were constructed through data fitting.Based on modified flow stress data,the constitutive equation was established,where the average error is decreased from 9.11%to 5.20%,and the correlation coefficient is increased from 0.95735 to 0.99756,verifying the accuracy of constitutive equation.