混料时间和挤压对SiC增强纯Al基复合材料显微组织和力学性能的影响

Effects of stirring time and extrusion on microstructures and mechanical properties of SiC reinforced pure Al matrix composites

采用粉末冶金法制备SiC颗粒增强工业纯Al基复合材料,研究混料时间和挤压对复合材料显微组织和力学性能的影响。研究表明:机械混粉过程存在最佳的混料时间,混料时间为16 h时SiC颗粒分布均匀,复合材料的密度高、力学性能好。挤压可以改善复合材料的界面结合强度、减少孔洞的数量,从而提高材料的致密度和力学性能。烧结态复合材料的断裂机制以基体的脆性断裂以及增强相与基体的界面脱粘为主。挤压态复合材料的断裂以基体的韧性断裂以及SiC颗粒的脆性断裂为主,伴随着少量的基体与SiC颗粒的界面脱粘。

The effects of stirring time and extrusion on the microstructures and mechanical properties of SiC particle reinforced pure Al matrix composites produced by powder metallurgy method have been investigated.It has been shown that during the mechanical stirring process,the distributed uniformity of SiC particles can improve the density and mechanical properties of the composites.It has also been shown that extrusion can increase the particle interfacial bonding strength,and decrease the number of pores,thus significantly improve the density and mechanical properties of the composite.The main fracture mechanisms of the as-sintered composite are the brittle fracture of the Al matrix and decohesion between the Al matrix and the SiC reinforcements.The main fracture mechanisms of the as-extruded composite are the ductile fracture of the matrix and the brittle fracture of the SiC particles,accompanied with some debonding between the Al matrix and the SiC particles.