Cu-Ni-Sn合金高温本构模型及动态再结晶行为

High Temperature Constitutive Model and Dynamic Recrystallization Behavior of Cu-Ni-Sn Alloy

以Cu-Ni-Sn合金为研究对象,在Gleeble-3800热模拟试验机进行变形温度为650~850℃,应变速率为0.001~1 s^(-1)的热压缩试验,根据采集数据绘制应力-应变曲线,构建Cu-Ni-Sn合金高温本构模型,确定动态再结晶临界条件,并基于Avrami方程建立其动态再结晶体积分数模型。结果表明,所构建的Cu-Ni-Sn合金本构模型与试验结果相符合,平均相对误差为5.06%;其动态再结晶体积分数与真应变之间呈S形变化,并且较高温度和较低应变速率有利于动态再结晶。

The hot compression behavior of Cu-Ni-Sn alloy with deformation temperature of 650~850℃and the strain rate of 0.001~1 s^(-1) was carried out on Gleeble-3800 thermal simulation testing machine.The high-temperature constitutive model of Cu-Ni-Sn alloy was constructed based on the stress-strain curves combined with the experimental data.The critical conditions of dynamic recrystallization were determined,and the volume fraction model was established based on Avrami equation.The results indicate that the constitutive model is well matched with the experimental results with the average relative error of 5.06%.The variation curve of dynamic recrystallization volume fraction with true strain is S-shaped,proving that the higher temperature and lower strain rate are favorable to the occurrence of dynamic recrystallization behavior.