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采用真空热压-内氧化烧结法成功制备Ti C粒径分别为3.2和25μm的30 vol%Ti C/Cu-Al2O3复合材料,对其进行了显微组织观察分析和性能测试;并利用Gleeble-1500D热力模拟试验机,研究了该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:随着Ti C粒径的增大,复合材料的相对密度和导电率有所增加,而硬度略有下降。Ti C/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30 vol%Ti C/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;热变形激活能随Ti C粒径增大而略有下降,其值分别为269.059 k J/mol(3.2μm)和234.288 k J/mol(25μm)。
A 30 vol% Ti C / Cu-Al2O3 composite with TiC particle sizes of 3.2 and 25 μm was successfully prepared by vacuum hot-press internal oxidation sintering method. Microstructure observation and performance testing were carried out. The Gleeble- 1500D thermal simulation test machine was used to study the thermal deformation behavior of the composites under the conditions of deformation temperature of 450 ~ 850 ℃ and strain rate of 0.001 ~ 1 s-1. The results show that with the increase of TiC particle size, the relative density and electrical conductivity of the composites increase, while the hardness decreases slightly. The true stress-true strain curves of TiC / Cu-Al2O3 composites are mainly characterized by dynamic recrystallization. The peak stress increases with the decrease of deformation temperature or the increase of strain rate. Under the condition of high temperature deformation, 30 vol% Ti C / The constitutive equation of rheological stress in Cu-Al2O3 composites can be described by the hyperbolic sine equation and Z parameter. The thermal deformation activation energy decreases slightly with the increase of TiC particle size, which are respectively 269.059 kJ / mol (3.2μm ) And 234.288 k J / mol (25 μm).