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通过半固态搅拌铸造和热挤压变形复合工艺制备出SiCp质量分数为1%的纳米SiCp/Mg-9Al-1Zn镁基复合材料。研究了搅拌时间分别为10和30 min时热挤压对纳米SiCp/Mg-9Al-1Zn镁基复合材料的显微组织和力学性能的影响。结果表明,对于铸态的纳米SiCp/Mg-9Al-1Zn镁基复合材料来说,搅拌时间为30 min时,基体的晶粒细化,但在晶界处析出的Mg_(17)Al_(12)相数量增多,网状化严重且SiC团聚增加,使得复合材料的力学性能下降。而通过热挤压后,复合材料形成了粗晶与细晶交替的组织结构。特别是对于搅拌时间为30 min的复合材料,细晶区增多且纳米SiC颗粒分布更加均匀,这就使得力学性能高于搅拌10 min的挤压态的SiCp/Mg-9Al-1Zn复合材料。
SiCp / Mg-9Al-1Zn nanocomposites with SiCp content of 1% were prepared by semi-solid stirring casting and hot extrusion deformation composite process. The effects of hot extrusion on the microstructure and mechanical properties of nano-sized SiCp / Mg-9Al-1Zn magnesium matrix composites were investigated when the stirring time was 10 and 30 min respectively. The results show that for the as-cast nano SiCp / Mg-9Al-1Zn magnesium matrix composites, the grain refinement of the matrix is observed when the stirring time is 30 min, but the precipitation of Mg 17 Al 12 ), The number of phases increased, the reticulation was serious and the agglomeration of SiC increased, which decreased the mechanical properties of the composites. Through hot extrusion, the composite material formed a coarse grain and fine grain alternating structure. Especially for the composites with a mixing time of 30 min, the grain refinement area increased and the distribution of nano-SiC particles became more uniform, which made the mechanical properties higher than that of SiCp / Mg-9Al-1Zn composites extruded for 10 min.