论文部分内容阅读
采用真空热压-内氧化烧结法制备TiC体积分数分别为0、10 vol%、20 vol%的TiC/Cu-Al2O3复合材料,观察和分析了其显微组织、测试和分析了其性能;利用Gleeble-1500D热力模拟试验机,研究了3种复合材料在变形温度为450~850℃,应变速率为0.001~1 s-1条件下的热变形行为。结果表明,复合材料的相对密度在97.1%以上,随着TiC含量的增加,其导电率下降、硬度升高。TiC/Cu-Al2O3复合材料的真应力-真应变曲线主要以动态再结晶机制为特征,峰值应力随变形温度的降低或应变速率的升高而增加;高温变形条件下TiC/Cu-Al2O3复合材料流变应力本构方程可以用双曲线正弦方程和Z参数描述;其热变形激活能分别为163.939 k J/mol(0 vol%TiC)、164.142 k J/mol(10 vol%TiC)和210.762 k J/mol(20 vol%TiC)。
The TiC / Cu-Al2O3 composites with TiC volume fraction of 0,10 vol% and 20 vol% were prepared by vacuum hot-press internal oxidation sintering. The microstructure was observed and analyzed, Gleeble-1500D thermal simulation test machine was used to study the thermal deformation behavior of three composites under the condition of deformation temperature of 450 ~ 850 ℃ and strain rate of 0.001 ~ 1 s-1. The results showed that the relative density of the composites was over 97.1%. With the increase of TiC content, the electrical conductivity decreased and the hardness increased. The true stress-strain curves of TiC / Cu-Al2O3 composites are mainly characterized by the dynamic recrystallization mechanism. The peak stress increases with the decrease of the deformation temperature or the strain rate. Under the high temperature deformation conditions, the TiC / Cu-Al2O3 composites The constitutive equation of flow stress can be described by the hyperbolic sine equation and Z parameter. The thermal deformation activation energies are 163.939 kJ / mol (0 vol% TiC), 164.142 kJ / mol (10 vol% TiC) and 210.762 k J / mol (20 vol% TiC).