超声表面滚压处理对AZ31B镁合金组织和性能的影响  

Effect of Ultrasonic Surface Rolling Process on Microstructure and Properties of AZ31B Magnesium Alloy

作　　者：耿纪龙 闫志峰[1,2] 张红霞[1,2] 董鹏[1] GENG Ji-long;YAN Zhi-feng;ZHANG Hong-xia;DONG Peng(College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China;Key Laboratory of Interface Science and Engineering in Advanced Materials,Ministry of Education,Taiyuan 030024,China)

机构地区：[1]太原理工大学材料科学与工程学院,太原030024 [2]先进材料界面科学与工程教育部重点实验室,太原030024

出　　处：《表面技术》2022年第1期368-375,共8页Surface Technology

摘　　要：目的研究AZ31B镁合金在超声表面滚压处理后,表面微观结构、显微硬度和表面粗糙度的变化及其在拉伸试验过程中对AZ31B镁合金内部组织的影响。方法利用超声表面滚压处理在AZ31B镁合金表面制备梯度变形层。利用X射线衍射仪、EBSD、显微硬度仪和表面粗糙度仪,分析试样表面的微观结构、显微硬度和表面粗糙度。对超声表面滚压处理前后试样进行拉伸试验,分析其拉伸性能和微观组织变形。结果经过9道超声表面滚压处理后,样品表层形成了厚约600μm的变形层。变形层组织呈梯度分布,分别为超细晶粒层、细粒过渡层和母材组织。随着与试样表面距离的增加,试样表面的显微硬度值为84~52HV10g。USRP试样的表面粗糙度Ra达到0.140μm。在拉伸过程中,相对于母材,超声表面滚压处理试样微观组织的变化量较少。结论相对于未处理试样,超声表面滚压处理试样的屈服强度提高了28%,显微硬度提高了40%,表面粗糙度降低了96.4%。同时,超声表面滚压处理在镁合金试样表层形成的梯度结构,在拉伸过程中降低了中心微观组织的变形。The changes of microstructure,microhardness and surface roughness of AZ31B magnesium alloy after ultrasonic surface rolling process(USRP)were investigated.And their effecton the internal microstructure of AZ31B magnesium alloy in the process of tensile test.A gradient deformation layer was generated on the surface of AZ31B magnesium alloy by USRP.The microstructure,microhardness and surface roughness of the samples were analyzed by X-ray diffractometer,EBSD,microhardness tester and surface roughness tester.Tensile tests were carried out on the untreated and USRPed samples to analyze the tensile properties and microstructure deformation.After 9 passes of USRP,a deformation layer about 200μm was formed on the surface of the sample.The microstructure of the deformed layer is gradient distribution:ultrafine grain layer,fine grain transition layer and base material.With the increase of the distance from surface of the sample,the microhardness of the sample surface is between 84HV10g and 52HV10g.The surface roughness of USRP specimen reaches Ra 0.140μm.Compared with the untreated sample,the microstructure changes of the USRPed sample are less.Compared with untreated samples,the yield strength and microhardness of the samples treated by ultrasonic surface rolling are increased by 28%and 40%.The surface roughness was reduced by 96.4%.And,the gradient structure formed by USRP on the surface of the magnesium alloy sample can reduce the deformation of the central microstructure during the tensile test.

关 键 词：AZ31B镁合金 超声表面滚压处理 梯度变形层 微观组织变形 

分 类 号：TG376[金属学及工艺—金属压力加工]