搅拌摩擦加工参数对镁合金表面改性层的影响  

Effect of friction stir processing parameters on the surface modification layer of magnesium alloy

作　　者：朱先勇 谢良稳 樊跃香 姜城 孙炜佳 王鹏 肖雄 ZHU Xian-yong;XIE Liang-wen;FAN Yue-xiang;JIANG Cheng;SUN Wei-jia;WANG Peng;XIAO Xiong(School of Mechanical and Aerospace Engineering,Jilin University,Changchun 130022,China;Chongqing Research Institute,Jilin University,Chongqing 401120,China)

机构地区：[1]吉林大学机械与航空航天工程学院,长春130022 [2]吉林大学重庆研究院,重庆401120

出　　处：《吉林大学学报（工学版）》2023年第8期2263-2271,共9页Journal of Jilin University:Engineering and Technology Edition

基　　金：吉林省发展和改革委员会项目(2021C038-4);吉林省科技发展计划项目(20210204143YY);长春市科技发展计划项目(21ZY25);吉林大学盐城智能终端产业研究院项目(JDYCYJY2021-15);吉林大学研究生创新基金项目(101832020CX116,101832020CX112);吉林大学重庆研究院项目(CQRIJLU2021CYGG018).

摘　　要：为改善镁合金表面的微观组织和力学性能,利用搅拌摩擦加工技术对Mg-3.4Al-0.8Zn-0.4Sn镁合金进行了表面改性。采用无针搅拌头,分别设置不同行进速度和旋转速度,通过分析热循环过程、观察表面改性层宏观形貌、进行微观组织表征以及显微硬度测量,研究了工艺参数对表面改性层的影响规律。研究结果表明:表面改性区可分为搅拌层、旋转流动层、过渡层以及热机械影响层;随着行进速度增加,热循环时间缩短且峰值温度降低,表面改性层的厚度减小,平均晶粒尺寸减小,显微硬度增大;随着旋转速度的增加,加工区域峰值温度升高,表面改性层的厚度增大,平均晶粒尺寸增大,显微硬度减小;各工艺参数下获得的改性层相比于母材晶粒明显细化,硬度有所增大。In order to improve the microstructure and mechanical properties on surface of magnesium alloys,the surface modification of Mg-3.4Al-0.8Zn-0.4Sn magnesium alloy was carried out by friction stir processing.By using a pin-less tool,setting a series of travel speeds and rotation speeds,analyzing the thermal cycle process,observing the macroscopic morphology of the surface modification zone,characterizing microstructure and measuring microhardness,the influence of process parameters on the surface modification layer was studied.The results show that,the surface modification zone can be divided into four layers including stir layer,rotation flow layer,transition layer and themo-mechanical affected layer.As the travel speed increases,the time and the peak temperature of the thermal cycle,the thickness of the surface modification layer and the average grain size decrease,while the microhardness increases.By contrast,as the rotation speed increases,the peak temperature of the thermal cycle,the thickness of the surface modification layer and the average grain size increase,while the microhardness decreases.The modification layer obtained at each parameter showed significant grain refinement and microhardness increment compared to the base material.

关 键 词：材料合成与加工工艺 镁合金 搅拌摩擦加工 表面改性 

分 类 号：TG178[金属学及工艺—金属表面处理]