Partial melting behavior and thixoforming properties of extruded magnesium alloy AZ91 with and without addition of SiC particles with a volume fraction of 15%
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2018年第7期
论文作者：Yu-Shi Yi Yi Meng Dan-Qing Li Sumio Sugiyama Jun Yanagimoto
文章页码：1149 - 1161
摘 要：A series of reheating-isothermal holding experiments and compression tests were conducted on pristine magnesium alloy AZ91 extruded by equal channel angular extrusion（ECAE） and Si C particles（a volume fraction of 15%） reinforced AZ91 composite（AZ91-SiCp） by regular extrusion. Dissolution of eutectic compounds and partial melting of the α-Mg matrix occurred during the reheating of these materials. Spherical semisolid slurries of these materials were obtained when the reheating temperature and isothermal holding time were 550?C and 20 s, respectively. The presence of SiCp in AZ91-Si Cpnot only caused lower liquid fractions of semisolid slurries but also resulted in higher values of flow stress during semisolid compression tests. Both AZ91 alloy and AZ91-Si Cpcomposite exhibited better thixoforming properties at high temperatures. Segregation of Si Cpdid not occur during thixoforming of AZ91-Si Cpcomposite after an isothermal holding at semisolid temperatures for 20 s.
Yu-Shi Yi1，Yi Meng1,2，Dan-Qing Li1，Sumio Sugiyama3，Jun Yanagimoto3
1. College of Materials Science and Engineering, Chongqing University2. National Engineering Research Center for Magnesium Alloys3. Institute of Industrial Science, The University of Tokyo
摘 要：A series of reheating-isothermal holding experiments and compression tests were conducted on pristine magnesium alloy AZ91 extruded by equal channel angular extrusion（ECAE） and Si C particles（a volume fraction of 15%） reinforced AZ91 composite（AZ91-SiCp） by regular extrusion. Dissolution of eutectic compounds and partial melting of the α-Mg matrix occurred during the reheating of these materials. Spherical semisolid slurries of these materials were obtained when the reheating temperature and isothermal holding time were 550?C and 20 s, respectively. The presence of SiCp in AZ91-Si Cpnot only caused lower liquid fractions of semisolid slurries but also resulted in higher values of flow stress during semisolid compression tests. Both AZ91 alloy and AZ91-Si Cpcomposite exhibited better thixoforming properties at high temperatures. Segregation of Si Cpdid not occur during thixoforming of AZ91-Si Cpcomposite after an isothermal holding at semisolid temperatures for 20 s.
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