采用复合分散铸造法制备了纳米SiC颗粒(n-SiCp)增强AZ91D复合材料,研究了复合材料在高温下的拉伸及断裂行为。结果表明:n-SiCp的加入可以提高复合材料的高温拉伸强度,高温下n-SiCp对复合材料的增强效果比室温更加明显;n-SiCp的加入还显著提高了复合材料在高温下的断后伸长率,复合材料具有较好的高温塑性。断口分析表明,n-SiCp的加入使复合材料在高温下的断裂行为由室温的脆性断裂为主转化为典型的韧性断裂。 The nano-SiC particles (n-SiCp) reinforced AZ91D composites were prepared by compound dispersion casting method. The tensile and fracture behaviors of the composites at elevated temperature were studied. The results show that the addition of n-SiCp can increase the tensile strength of the composites at high temperature, and the enhancement effect of n-SiCp on the composites at room temperature is more obvious than that at room temperature. The addition of n-SiCp also significantly improves the fracture toughness of composites at high temperature Elongation, the composite material has good high temperature plasticity. Fracture analysis shows that the fracture behavior of the composites at high temperature is mainly transformed from the brittle fracture at room temperature into the typical ductile fracture with the addition of n-SiCp.