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采用高压扭转法(HPT)将不同尺寸的SiC颗粒和工业纯Al混合粉末直接固结成形制备SiC_P/Al复合材料。利用排水法测量复合材料的体积并计算致密度,再通过拉伸试验及拉伸断口扫描电镜观察,研究SiC颗粒粒径对复合材料致密度和拉伸性能的影响。结果表明,在200℃下,由于SiC颗粒含量一定,随着颗粒尺寸的增大,颗粒数量减少,比表面积逐渐减小,大颗粒受剪切作用而发生破碎的趋势加剧,结合不牢固的新生界面增加,导致复合材料致密度和抗拉强度呈先升高后降低的趋势;同时拉伸断口处韧窝尺寸逐渐增大,分布均匀性降低,韧窝处残留颗粒增加,复合材料韧性断裂特征减弱,脆性断裂特征增强。
The SiC_P / Al composites were prepared by direct solidification of different sizes of SiC particles and industrial pure Al mixed powders by HPT. The volume of the composite was measured by drainage method and the density was calculated. The tensile test and tensile fracture scanning electron microscopy were used to investigate the effect of SiC particle size on the densification and tensile properties of the composites. The results show that with the increase of particle size, the number of particles decreases and the specific surface area decreases with the increase of SiC particle size at 200 ℃. The tendency of large particles to be crushed by shearing is aggravated. Combined with weak neonatal As the interface increases, the density and tensile strength of the composites tend to increase at first and then decrease. At the same time, the size of the dimples gradually increases, the distribution uniformity decreases, the residual particles in the dimples increase, and the ductile fracture characteristics of the composites Weakened, brittle fracture enhanced.