摘要
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。
1 wt% SiC nanoparticles reinforced Mg-9Al-1Zn magnesium matrix composite was fabricated by stir casting and hot extrusion. Effect of hot extrusion on microstructure and mechanical properties of SiCp/Mg-9Al-1Zn nanocomposite stirring for 10 min and 30 min was researched. The results show that the grains of the matrix in the as-cast SiCp/Mg-9Al-1Zn nanocomposite stirring for 30 min are mainly refined. But the mechanical properties of nanocomposite decline due to the increase of agglomerated SiC nanoparticles and Mg_（17）Al_（12） phases with network morphology along the grain boundaries. After hot extrusion, a bimodal microstructure composed of alternate arrays of fine DRXed grains and relatively coarse DRXed grains forms. Particularly, for extruded nanocomposites stirring for 30 min, the fine DRXed region increases and the distribution of SiC nanoparticles is more homogenous, which exhibits superior mechanical properties compared with as-extruded SiCp/Mg-9Al-1Zn nanocomposite stirring for 10 min.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2017年第10期2847-2851,共5页
Rare Metal Materials and Engineering
基金
National Natural Science Foundation of China(51301118,51404166)
International Cooperation in Shanxi(2014081002)
Technological Innovation Programs of Higher Education Institutions in Shanxi(2013108)
