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以Al-Si合金粉末和B4C粉末为原料,采用粉末热挤压法制备了B4C/Al-Si复合材料,研究了挤压温度对该复合材料组织和性能的影响。结果表明:挤压温度为350～500℃时,B4C在Al-Si基体中均匀分布,无团聚现象;挤压温度为450℃及以上时,挤压组织达到致密化;随着挤压温度的升高,该复合材料的抗拉强度、屈服强度和屈强比降低,伸长率增大;挤压温度超过450℃时,基体中的Si相数量明显减少,晶粒显著增大;拉伸断裂是微孔聚集型韧性断裂,韧窝是该复合材料拉伸断口的主要特征。
B4C / Al-Si composites were prepared by powder hot extrusion from Al-Si alloy powders and B4C powders. The effects of extrusion temperature on the microstructure and properties of the composites were investigated. The results show that when the extrusion temperature is 350-500 ℃, B4C is uniformly distributed in the Al-Si matrix without agglomeration. When the extrusion temperature is 450 ℃ and above, the extrusion structure is densified. With the extrusion temperature The tensile strength, yield strength and yield ratio of the composites decreased and the elongation increased. When the extrusion temperature exceeded 450 ℃, the amount of Si phase in the matrix decreased significantly and the grain size increased significantly. Fractures are microporous aggregated ductile fractures, dimples being the main feature of the composite tensile fracture.