搅拌摩擦加工AZ31镁合金的超塑性

摘要

对搅拌摩擦加工AZ31镁合金的微观组织和拉伸力学行为进行了研究.结果表明,通过搅拌摩擦加工,热轧AZ31板材的平均晶粒尺寸由92.0 μm细化到11.4 μm.搅拌摩擦加工板材在高温下具有优异的塑性,伸长率在温度为723 K和应变速率为5×10-4s-1的条件下达到1050％.该材料还具有高应变速率超塑性,在723 K和1×10-2 s-1的条件下伸长率达到268％.在相同实验条件下,母材由于晶粒尺寸粗大,没有显示出超塑性.%Microstructure and tensile behaviors of AZ31 magnesium alloy prepared by friction stir processing(FSP)were investigated.The results show that microstructure of the AZ31 hot-rolled plate with an average grain size of 92.0 μm is refined to 11.4 μm after FSP.The FSP AZ31 alloy exhibits excellent plasticity at elevated temperature,with an elongation to failure of 1050％ at 723 K and a strain rate of5×10 4 s-1,The elongation of the FSP material is 268％ at 723 K and 1×10-2 S-1,indicating that high strain rate superplasticity could be achieved.On the other hand,the hot-rolled base material,which has a coarse grain structure,possesses no superplasticity under the experimental conditions.