轧制路径对ZK60镁合金板材组织和性能的影响

在250 ℃对轧制-热处理态ZK60镁合金板材进行9道次不同路径的轧制试验。采用光学显微镜、电子万能试验机、SEM、XRD等研究了轧制试验后ZK60镁合金的显微组织、室温拉伸性能、断口形貌及晶粒择优取向。结果表明:轧制路径对ZK60镁合金板材的晶粒尺寸变化无明显影响,但压下量对镁合金组织内的孪晶变化有很大影响;轧制路径的变化对ZK60镁合金板材的各向异性和力学性能有较大影响,在交叉+45°的路径下轧制后ZK60镁合金板材,各向异性较弱,具有良好的综合力学性能和轧制成形能力,其屈服强度、抗拉强度和伸长率分别达到244.31 MPa、371.14 MPa和25.46%;交叉+45°路径轧制对ZK60镁合金的晶粒择优取向有明显影响,能够改善镁合金板材的晶粒择优取向和各向异性,提高ZK60镁合金的力学性能。

Effect of rolling route on microstructure and properties of ZK60 magnesium alloy sheets

Rolled and heat treated ZK60 magnesium alloy sheets were re-rolled for nine passes at 250 ℃ by different routes. Microstructure, room temperature tensile properties, fracture morphology and grains preferred orientation of ZK60 magnesium alloys after re-rolling were researched by means of optical microscopy, electronic universal testing machine, SEM and XRD. The results indicate that the rolling route has no obvious effect on the grain size of ZK60 magnesium alloy sheets, but the reduction has a great influence on the twin forming in the structure of magnesium alloy. The change of rolling route has greater effect on anisotropy and mechanical properties of ZK60 magnesium alloy sheet. The ZK60 magnesium alloy sheet rolled under the route of cross+45° has weak anisotropy and good comprehensive mechanical properties, its yield strength, tensile strength and elongation reach 244.31 MPa, 371.14 MPa and 25.46% respectively. The cross+45° rolling has a significant effect on the grains preferred orientation of ZK60 magnesium alloy sheets, which can improve the preferred grain orientation and anisotropy and the plastic deformation properties of ZK60 magnesium alloy.