表面机械研磨处理对AZ31镁合金力学性能的影响  

Effect of surface mechanical attrition treatment on mechanical properties of AZ31 magnesium alloy

作　　者：吴勇 张真[1] 陈欢欢 龙昌 张雨生 杨明赛 杜晓东[1] 陈畅[1] 王珊 吴玉程 WU Yong;ZHANG Zhen;CHEN Huan-huan;LONG Chang;ZHANG Yu-sheng;YANG Ming-sai;DU Xiao-dong;CHEN Chang;WANG Shan;WU Yu-cheng(School of Materials Science and Engineering,Hefei University of Technology,Hefei 230009,China;Institute of Industry and Equipment Technology,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]合肥工业大学材料科学与工程学院,安徽合肥230009 [2]合肥工业大学工业与装备技术研究院,安徽合肥230009

出　　处：《塑性工程学报》2022年第11期216-223,共8页Journal of Plasticity Engineering

基　　金：国家自然科学青年基金资助项目(51401072,51605128)。

摘　　要：通过表面机械研磨处理在AZ31镁合金表层制备了局部变形层组织,并测试了性能随组织的变化规律。结果表明,表面机械研磨处理可以制备出母材-孪晶-纳米晶的梯度结构。在相同的研磨时间下,大晶粒样品相较小晶粒样品形成的纳米层更厚,并且大晶粒样品在研磨2 h后纳米层厚度趋于稳定。在表面机械研磨处理过程中,基面织构的强度随研磨时间的增加先大幅降低后逐渐升高。显微硬度沿板材厚度方向先减小后增大。断口形貌分析表明,断口边缘断裂模式为韧脆混合断裂,芯部断裂为塑性断裂,样品断裂是裂纹由表面向芯部扩展的结果。表面机械研磨处理制备纳米晶的机理是位错聚集在孪晶界形成细小的高能亚晶,高能亚晶发生动态再结晶获得纳米晶。The local deformation layer structure was prepared on the surface of AZ31 magnesium alloy by surface mechanical attrition treatment(SMAT),and the change law of performance with the structure was tested.The results show that SMAT can prepare the gradient structure of base material-twin crystal-nanocrystalline.With the same attrition time,the nano-layer of the sample with large grains is thicker than that of the sample with small grains,and the nano-layer thickness of the sample with large grains tends to be stable after 2 h attrition.During the SMAT process,the basal texture strength decreases significantly first and then increases gradually with the increase of attrition time.The microhardness decreases first and then increases along the thickness direction of plate.The fracture morphology analysis show that the fracture mode at the fracture edge is ductile and brittle mixed fracture,the fracture of core is plastic fracture,and the fracture of sample is the result of crack spreading from surface to core.The mechanism of SMAT nanocrystalline preparation is that the dislocation gathers at the twin crystal boundary to form fine high-energy subgrains,and high-energy subgrains undergo dynamic recrystallization to obtain nanocrystalline.

关 键 词：AZ31镁合金 表面机械研磨 动态再结晶 纳米晶 

分 类 号：TG146[一般工业技术—材料科学与工程]