高体分SiCp/Al复合材料热变形行为及组织的研究

The Research of Hot-deformation Behavior and Microstructure of SiCp/Al Composite with High Volume Fraction

在应变速率为0.0005～0.01 s-1、变形温度为700～900℃条件下,对高体积分数SiC颗粒增强Al基复合材料进行了高温压缩实验,研究了复合材料高温压缩流变应力,观察了复合材料压缩后的组织形貌。结果表明:SiCp/Al复合材料在热压缩变形中发生了伪塑性变形,流变应力随应变速率的增加而增加,随变形温度的增加而降低;通过线性回归分析计算了复合材料的应变指数n以及变形激活能Q,获得了材料高温条件下的流变应力本构方程;高温压缩后的复合材料,颗粒尺寸、圆整度及分布均匀性明显提高。

Hot compression on the composite was tested at strain rates range from 0. 0005 s^-1 to 0.01s^-1 , deformation temperatures from 700 ℃ to 900 ℃, the flow stress behavior was researched, microstructure and properties of composite were observed and measured. The results show that： SiCp/Al composite with high volume fraction showed Pseudo-plastic deformation during hot compression, the flow stress increased with raising strain rates, decreased with raising deformation temperatures; strain exponent n and deformation activation energy Q were calculated in term of linear regression analysis, flow stress constitutive equation was got on hot compression conditions;the size, roundness and distribution uniformity of SiC particle increased obviously after hot compression.