高压低温烧结 AZ91细晶镁合金及其力学性能的研究

摘要

为了细化镁合金晶粒，对AZ91粉末采用高压低温烧结方法制备细晶 AZ91镁合金，利用金相显微镜和X射线衍射仪（XRD）分析了烧结体的显微组织与成分，研究了烧结时间与致密度和硬度的关系，揭示了高压低温烧结过程中烧结体内组织的细化与生长机理。结果表明，在1200 M Pa、300℃条件下烧结48 h后，晶粒平均尺寸约10μm ，致密度达到99.5％；与铸态时相比，高压低温烧结法制备的镁合金，其显微硬度（H V ）值从81.6提高到103。本研究对回收利用工业镁合金废屑、拓展高性能镁合金研究提供一种新途径。%In order to refine magnesium grain ,AZ91 alloy with refined grains was prepared by high‐pressure and low‐temperature sintering .The microstructure evolution of sintered alloy was studied by means of metallographic microscope and X‐ray diffraction (XRD) .The effect of sinte‐ring time on the density and hardness of AZ91 alloy was also analyzed .The grain refinement and growth of sintered alloy during high‐pressure and low‐temperature sintering were investigated . The results reveal that AZ91 alloy was sintered completely after 48 hours under 1 200 MPa and 300 ℃ .The average grain size of the sintered alloy was about 10μm .Moreover ,the relative den‐sity of the sintered AZ91 alloy was 99.5% and the hardness of sintered alloy prepared by high‐pressure and low‐temperature sintering increased obviously ,from 81.6 HV of the cast alloy to 103 HV .AZ91 alloy with refined grains was prepared by high‐pressure and low‐temperature sin‐tering ,hoping to provide a new method for recycling industrial magnesium alloy chips and expan‐ding high‐performance magnesium alloy research .