Fine-grained Mg–1Mn–0.5Al–0.5Ca–0.5Zn alloy with high strength and good ductility fabricated by conventional extrusion
Guang-lin GU, Xiangnan Ke, Faping Hu, Shujie Zhao, Guo-bin WEI, Yan Yang, Xiaodong Peng, Weidong Xie
Abstract
Mg–1Mn–0.5Al–0.5Ca–0.5Zn (wt.%) alloy was fabricated by conventional extrusion at 673 K with an extrusion ratio of 25:1, followed by aging at 473 K. The microstructure was characterized by scanning electron microscopy, electron back-scattered diffraction, and transmission electron microscopy. The mechanical properties were determined by the tensile test. The peak-aged sample shows fine recrystallized grains with an average grain size of 1.7 μm. Area fraction of Al–Ca particles in the alloy increases significantly after peak aging. Meanwhile, both 〈a〉 and 〈c+a〉 dislocations were observed to remain in the alloy after hot extrusion. Thus, the peak-aged sample exhibits simultaneously high strength and good ductility with the ultimate tensile stress, tensile yield stress, and tension fracture elongation of 320 MPa, 314 MPa, and 19.0%, respectively.