Processing and mechanical properties of SiC particulate reinforced AZ91 composites fabricated by stir casting

• Published in: Transactions of Nonferrous Metals Society of China Vol. 16; no. A03; pp. 1840 - 1844
• Main Author: 王晓军 吴昆 彭德林 张海峰 郑明毅 黄文现
• Format: Journal Article
• Language: English
• Published: School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China 01.12.2006
• Subjects: 机械性能; 碳化硅; 金属化合物; 金属铸造; 镁合金; stir casting; AZ91 composites; SiC; magnesium matrix composite; mechanical properties; extrusion
• ISSN: 1003-6326

The influence of stirring parameters （stirring temperature, stirring speed and stirring time） on the particle distribution of 10%（volume fraction） SiC particulate reinforced AZ91 composites （SiCp/AZ91） was studied. It is found that it is necessary for 10μm SiC particulate reinforced AZ91 composites to stir the molten composites in semi-solid condition with vortex formation, or else the cluster of the reinforcements would not be eliminated. Compared with the monolithic alloy, the SiCp/AZ91 composite has higher strength, especially for yield strength, but the elongation is reduced. For the as-cast composite, the particles often segregate within the grain boundary regions. Extrusion can effectively reduce the segregation of SiC particles and improve the mechanical properties of the composite. The extrusion-induced reduction in particle size varies with extrusion temperatures and extrusion ratios. The effect of extrusion-induced reduction in particle size on the mechanical properties of the composites is not always beneficial.