Effect of Ca and Sm Combined Microalloying on Microstructure and Mechanical Properties of AZ31 Alloy
Author of the article:GUO Chunrong;FU Li;LE Qichi;JLA Zheng;LU Lin
Author's Workplace：College of Mechanical Engineering,Shenyang University,Shenyang 110044,China;Key Lab of Electromagnetic Processing of Materials,Ministry of Education,Northeastern University,Shenyang 110819,China
Key Words：magnesium alloy Sm Ca microstructure mechanical properties
Abstract：Based on AZ31 alloy,the microstructure of as-cast and extruded alloy was analyzed by adding Ca(0.3%)and Sm(0.3%),and the tensile mechanical properties of AZ31 alloy were tested at room temperature and high temperature.The microstructure of the alloy was observed by optical microscope(OM)and scanning electron microscope(SEM).The phase composition was analyzed by X-ray diffractometer(XRD).The results show that the microstructure of as-cast AZ31-0.3Ca-0.3 Sm alloy is mainly composed of-Mg matrix,discontinuousβ-Mg17Al12 phase,new phase Al11Sm3 and a small amount of Al2Ca phase.In the extruded state,the grain size is refined and unevenly distributed,and the average grain size of dynamic recrystallization is 9.5μm.After extrusion,the yield strength Rp0.2 at room temperature is 180 MPa,the ultimate tensile strength Rm is 261 MPa,and the elongation A is 18.0%.At 150℃,the yield strength Rp0.2 is 125 MPa,the ultimate tensile strength Rm is 148 MPa,and the elongation A is 52.2%.
