TiC含量对TiC/Cu-Al_2O_3复合材料热变形行为的影响  

Effect of TiC content on hot deformation behavior of TiC/Cu-Al_2O_3 composites

作　　者：刘勇[1,2] 李辉[3] 杨志强[1] 田保红[1,2] 张毅[1,2] 

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471023 [2]有色金属共性技术河南省协同创新中心,河南洛阳471023 [3]开封大学机械与汽车工程学院,河南开封475004

出　　处：《材料热处理学报》2015年第7期1-6,共6页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(51101052);河南省高校重点科研项目(15A430006)

摘　　要：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 various TiC content of 0,10 vol% and 20 vol% were prepared by hot-pressed sintering process in vacuum. The microstructure and properties of the three composites were determined,and the hot deformation behaviors of the TiC / Cu-Al2O3 composites were investigated by the Gleeble-1500 D thermal simulator at 450-850 ℃ with the strain rate of 0. 001-1 s^- 1.The results show that the relative densities of the composites are higher than 97. 1%. The electrical conductivity decreases and the microhardness increases with increasing TiC content. The features of the high-temperature flow stress-strain curves of the TiC / Cu-Al2O3 composites indicate that the softening mechanism of the composites is the dynamic recrystallization. The peak stress increases with decreasing deformation temperature or increasing strain rate. The constitutive relation of the TiC / Cu-Al2O3 composites under hightemperature conditions can be described by the hyperbolic-sine-type equation and Z parameter. The activation energies of the composites are 163. 939 k J / mol（ 0 vol% TiC）,164. 142 k J / mol（ 10 vol% TiC） and 210. 762 k J / mol（ 20 vol% TiC）,respectively.

关 键 词：TiC/Cu-Al2O3复合材料 热变形 激活能 本构方程 

分 类 号：TB331[一般工业技术—材料科学与工程] TG146.1[金属学及工艺—金属材料]