Al_2O_3-TiC/Cu复合材料的热变形行为及流变应力的本构方程计算

Hot-Deformation Behavior and Flow Stress Calculated by Constitutive Equation for Al_2O_3-TiC/Cu Composite

采用热压烧结技术制备了原位自生的Al_2O_3-TiC/Cu复合材料。采用Gleeble-1500D热模拟试验机进行了Al_2O_3-TiC/Cu复合材料的单轴等温压缩试验。研究了Al_2O_3-TiC/Cu复合材料在不同应变速率和不同变形温度下的热变形行为,并建立了本构方程。结果表明:Al_2O_3-TiC/Cu复合材料的真应力-真应变曲线表现的热变形机制主要为动态回复,随着应变速率的增大或变形温度的降低,峰值应力增大;Al_2O_3-TiC/Cu复合材料的流变应力、流变温度和应变速率之间的关系可用双曲线正弦函数描述。

A in-situ grown Al2 O3-TiC/Cu composite was prepared by a hot pressing sintering process. The trial uniaxial isothermal compression of the Al2 O3-TiC/Cu composite was performed in a Gleeble-1500 D thermal simulation tester. Behavior of hot deformation at different strain rates at different temperatures was investigated, and the constitutive equation was established. It turned out that the true stress-true strain curve of the Al2 O3-TiC/Cu composite was mainly characterized by a dynamic recovery mechanism, and that the peak stress increased with the increase of strain rate or the decrease of deformation temperature. The relationship among the flow stress,rheological temperature and strain rate for Al2 O3-TiC/Cu composite can be described by a hyperbolic sine function.