(1. 江蘇技術師范學院 機械工程學院，常州 213001；
2. 江蘇大學 機械工程學院，鎮(zhèn)江 212013)
摘 要: 采用 CO2 連續(xù)激光對 AM
關鍵字: AM50A鎂合金；激光表面熔凝；細晶強化；固溶強化；彌散強化
（1. School of Mechanical Engineering, Jiangsu Teachers University of Technology, Changzhou 213001,China;
2. School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013,China）
Abstract:AM50A magnesium alloy was surface melted using a continuous wave CO2 laser, the microstructure properties and strengthening mechanism of the laser melted layer were analyzed. The results show that the grain of the laser surface melted layer is highly refined and the grain size decreases with increasing scanning speed. In the melted layer, the amount of element Al in solid solution increases, the amount of β-phase (Mg17Al12) decreases, and the distribution of β-phase becomes more uniform. The micro-hardness of the melted layer is improved to HV55−75 as compared to that of the substrate (about HV40). The wear volume of the laser surface melted sample is 35% of the untreated sample, the wear resistance of the laser surface melted layer is improved obviously. The main strengthening mechanism of the laser surface melted layer is grain refinement, the increase of element Al in solid solution and the dispersive precipitation of β-phase can also result in strengthening the melted layer.
Key words: AM50A magnesium alloy; laser surface melting; fine grain strengthening; solid solution strengthening; dispersion strengthening
