Effects of Aluminum Content on the Microstructure and Mechanical Properties of AZ Magnesium Alloys
Zhang Guangjun1,Long Siyuan2,Cao Fenghong1 (1. College of Materials Science and Engineering,Chongqing University,Chongqing,China; 2. National Engineering Research Center for Magnesium Alloys,Chongqing University,Chongqing,China)
Effects of different Al contents on microstructure and mechanical properties of AZ series magnesium alloys were investigated. The results reveal that with increasing in Al content,numbers of Mg17Al12 phase distributed into α-Mg phase are increased with more continuous distribution in microstructure of Mg alloy,however,with 8% Al content,the α-Mg phase is isolated by the network Mg17Al12 phase. The mechanical properties of the alloy are closely related to the microstructure characteristics of α-Mg phase and Mg17Al12 phase. AZ71 magnesium alloy exhibits the best mechanical properties among three types of alloys. As-cast tensile strength,yield strength and elongation of the AZ71 alloy reach 211.63MPa,109.84MPa and 7.20%,respectively,and after solid solution treatment,tensile strength,yield strength and elongation reach 235.98MPa,122.12MPa and 14.72%,respectively. The distribution of brittle Mg17Al12 phase greatly affects crack propagation in tensile samples. The fracture morphologies of all AZ series alloys are characterized by brittle fracture.
【CateGory Index】： TG146.22