二次挤压对Mg-5.0Gd-4.0Ni-0.5Cu-0.8Y-0.5Zn合金显微组织及力学性能均匀性的影响

Effect of Secondary-extrusion on Microstructure and Mechanical Properties Homogeneity of Mg-5.0Gd-4.0Ni-0.5Cu-0.8Y-0.5Zn Alloy

采用金相显微镜、电子扫描显微镜、万能拉伸试验机等研究了一次挤压(E1)、二次挤压(E2)对Mg-5.0Gd-4.0Ni-0.5Cu-0.8Y-0.5Zn合金棒材显微组织及力学性能均匀性的影响。结果表明:一次挤压后,合金心部呈现双峰组织,边部是均匀的细晶组织,棒材织构整体呈现基面织构且心部织构显著强于边部,边部强度和伸长率明显高于心部;二次挤压后,边部和心部都是均匀的细晶组织,心部织构显著降低,但仍略高于边部,力学性能进一步提高,在不同部位基本一致。二次挤压显著提高了可溶解镁合金组织及力学性能的均匀性。

The effect of single-extrusion(E1) and secondary-extrusion(E2) on the microstructure and mechanical properties homogeneity of Mg-5.0 Gd-4.0 Ni-0.5 Cu-0.8 Y-0.5 Zn alloy were studied by optical microscope(OM), scanning electron microscope(SEM) and universal tensile testing machine. The results show that after single-extrusion, the core of the alloy presents bimodal grain microstructure and the edge is a homogeneous fine-grained microstructure. The bar’s texture overall presents base texture and the texture of the core is significantly stronger than that of the edge,and the edge strength and elongation are significantly higher than those of the center. After secondary-extrusion, both the edge and the core are a homogeneous fine-grained microstructure, and the texture of the core is obviously reduced, but still slightly higher than that of the edge. The mechanical properties are further improved and basically consistent in different parts. The secondary extrusion dramatically improves the homogeneity of microstructure and mechanical properties of the dissolvable magnesium alloy.