双峰晶粒结构AZ80镁合金的制备与组织性能

Preparation, microstructure and properties of AZ80 magnesium alloy with bimodal grain size

为了制备具有双峰晶粒结构的AZ80镁合金,选取铸态AZ80镁合金作为初始试样,将试样固溶处理后进行等通道转角挤压(ECAP)实验,之后利用OM和SEM等测试技术分析了等通道转角挤压后试样的组织形态,研究了双峰晶粒结构组织对AZ80镁合金力学性能的影响。结果表明,变形后固溶处理试样的组织由原始粗晶和经动态再结晶形成的细晶组成的双峰组织。所有试样经ECAP变形后力学性能均显著高于初始试样,且在变温ECAP下试样的力学性能更优,其抗拉强度的平均值为375.1 MPa,是铸态试样的181.49%,伸长率平均值为14.8%,是铸态试样的269.09%。因此,通过ECAP变形获得晶粒尺寸呈双峰分布的组织,从而使力学性能显著提高的方法是可行的。

To prepare AZ80 magnesium alloy with bimodal grain structure, as-cast AZ80 magnesium alloy was selected as the initial sample, and the equal channel angular pressing(ECAP) experiment was carried out on the sample with solution treatment. Then, OM, SEM and other testing techniques were used to analyze the microstructure morphology of samples after ECAP, and the effect of bimodal grain structure on mechanical properties of AZ80 magnesium alloy was studied. The results show that the microstructures of samples after solution treatment and deformation are composed of coarse original grains and fine grains formed by dynamic recrystallization. The mechanical properties of all samples after ECAP deformation are significantly higher than those of as-cast samples, and the mechanical properties of samples under ECAP at variable temperatures are better. The average tensile strength is 375.1 MPa, which is 181.49% of as-cast sample, and the average elongation is 14.8%, which is 269.09% of as-cast sample. Therefore, it is feasible to obtain bimodal grain size distribution microstructure through ECAP deformation, so as to significantly improve mechanical properties.