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 SiC particles （a volume fraction of 15%） reinforced AZ91 composite （AZ91-SiCp） by regular extrusion. Dissolution of eutectic com- pounds and partial melting of the ct-Mg matrix occurred during the reheating of these materials. Spherical semisolid slurries of these materials were obtained when the reheating temperature and isothermal hold- ing time were 550℃ and 20 s, respectively. The presence of SiCp in AZ91-SiCp not only caused lower liquid fractions of semisolid slurries but also resulted in higher values of flow stress during semisolid compression tests. Both AZgl alloy and AZ91-SiCp composite exhibited better thixoforming properties at high temperatures. Segregation of SiCp did not occur during thixoforming of AZ91-SiCp composite after an isothermal holding at semisolid temperatures for 20 s.2018 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.
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 SiC particles （a volume fraction of 15%） reinforced AZ91 composite （AZ91-SiCp） by regular extrusion. Dissolution of eutectic com- pounds and partial melting of the ct-Mg matrix occurred during the reheating of these materials. Spherical semisolid slurries of these materials were obtained when the reheating temperature and isothermal hold- ing time were 550℃ and 20 s, respectively. The presence of SiCp in AZ91-SiCp not only caused lower liquid fractions of semisolid slurries but also resulted in higher values of flow stress during semisolid compression tests. Both AZgl alloy and AZ91-SiCp composite exhibited better thixoforming properties at high temperatures. Segregation of SiCp did not occur during thixoforming of AZ91-SiCp composite after an isothermal holding at semisolid temperatures for 20 s.2018 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.
基金
financially supported by the National Natural Science Foundation of China (No. 51605055)
Chongqing Natural Science Foundation (No. cstc2016jcyj A1027)
Fundamental Research Funds for the Central Universities (No. 0903005203307)
