预变形对AZ80镁合金组织与力学性能的影响

摘要

Effects of cold pre-compression on microstructure and mechanical properties of AZ80 Mg alloy were studied through optical microscope (OM) and electronic backscattering diffraction (EBSD) technology. The results show that twins can be induced by pre-compression at ambient temperature. The twin density increases with pre-compression strain, leading to higher fraction of recrystallization in the sample after hot compression. The average size of recrystallized grain is hardly affected by pre-compression strain. Excellent ductility and high strength can be achieved in AZ80 Mg alloy with pre-compression. After pre-compressed to ε = 15%, the yield strength and the ultimate tension strength achieve 216 MPa and 330 MPa, and the fracture elongation reaches 14.1%, which are increased by 12.5%, 6.5% and 33.0%, respectively.%通过光学显微镜(OM)、电子背散射衍射分析技术(EBSD)研究了低温压缩预变形对AZ80镁合金组织及力学性能的影响。结果表明：室温压缩预变形引入孪晶，孪晶密度随着预变形程度增大而增大；预变形程度越大，高温压缩后再结晶体积分数越高。再结晶晶粒尺寸不受预变形的影响。预变形试样比无预变形试样不仅强度略有提升，且塑性提升明显，预变形程度越大，提升效果越明显。预变形15%的试样的屈服强度、抗拉强度及断裂延伸率分别为216MPa、330MPa和14.1%，相对于无预变形试样分别提高12.5%、6.5%和33.0%。