冷轧变形量对Mg-9Li-1Zn合金组织和性能的影响

Effects of Cold Rolling Deformation on Microstructure and Properties of Mg-9Li-1Zn Alloy

采用显微组织观察、室温拉伸、硬度测试研究了冷轧变形量对Mg-9Li-1Zn合金在不同加工状态下显微组织和力学性能的影响。结果表明:铸态Mg-9Li-1Zn合金组织为α-Mg和β-Li的两相混合组织。随着冷轧变形量的增加,合金中α-Mg相和β-Li相逐渐被拉长,两相取向性越来越明显。在变形量80%的合金中,α-Mg相和β-Li相的组织明显细化,呈细条状分布。随着冷轧变形量的增加,合金的抗拉强度、硬度逐渐升高,伸长率逐渐降低。变形量80%的合金抗拉强度达到197MPa,硬度达到74.3HV,但伸长率降到9.0%。合金冷轧后200℃×1 h退火处理,合金的塑性明显改善,80%变形量轧制合金退火后伸长率达到24.1%。

The effects of cold rolling deformation on the microstructure and mechanical properties of Mg-9 Li-1 Zn alloy under different processing conditions were studied by means of microstructure observation, room temperature tensile test and hardness test. The results show that the microstructure of the as-cast Mg-9 Li-1 Zn alloy is a two-phase mixed microstructure of the α-Mg and β-Li. With the increases of cold rolling deformation, the α-Mg phase and β-Li phase in the alloy are gradually elongated, and the orientation of the two phases is more and more obvious. In the alloy with 80% deformation, the microstructure of the α-Mg phase and β-Li phase is obviously refined and distributed in fine strips. With the increases of cold rolling deformation, the tensile strength and hardness of the alloy increase gradually, and the elongation decreases gradually.The tensile strength and hardness of the alloy with 80% deformation reach 197 MPa and 74.3 HV respectively, but the elongation decreases to 9.0%. After cold rolling and annealing at 200℃×1 h, the plasticity of the alloy is obviously improved,and the elongation of 80% deformation rolled alloy reaches 24.1% after annealing.