异步轧制AZ31镁合金板材的晶粒细化及性能

采用上下轧辊速比1.125的异径异步轧制方法对AZ31镁合金板材进行轧制。采用光学显微镜、X射线衍射仪和电子拉伸机等设备分析轧制前后AZ31镁合金板材的微观组织和力学性能。结果表明:AZ31镁合金热挤压板坯在加热到350℃后,经一道次38%压下率的异步轧制,可获得平均晶粒尺寸为2.8μm的等轴晶粒,板材轧制方向的伸长率和抗拉强度显著增加;轧制过程中形成了非基面晶粒取向;伸长率的增大与晶粒细化和非基面织构的形成有关,抗拉强度的增大归因于晶粒的显著细化效应。

Grain Refinement and Properties of AZ31 Magnesium Alloy Sheets Deformed by Differential Speed Rolling

AZ31 magnesium alloy sheets were rolled by applying a circumferential velocity ratio of 1.125 between the upper and lower rolls in different diameter rolling.Microstrueture and mechanical properties of the sheets before and after rolling were observed and analyzed by optical microscopy,X-ray diffraction,and electronic draw-frame.The results indicated that a fine equiaxed grain size of 2.8μm could be achieved in AZ31 magnesium alloy hot-extrusion sheets when heated to 350℃ after a single pass of 38%thickness reduction.The elongation and tensile strength along the rolling direction were significantly enhanced.Non-basal plane grain orientation was formed during the rolling.The increase of elongation was related to the grain refinement and the formation of non-basal plane grain orientation,and the increase of tensile strength was attributed to the significant grain refinement effect.