为研究激光表面微凹坑对AZ31B 镁合金耐腐蚀性能的影响，利用光纤激光器在材料表面制备微凹坑阵列。通过扫描显微镜观测微凹坑的形貌、直径和深度，利用双单元电化学工作站测试微凹坑制备前后材料表面的动电位极化曲线。结果表明: 微凹坑的直径和深度均随激光功率的增大而增大，微凹坑周围出现烧蚀现象；微凹坑直径与扫描次数无显著相关性，但微凹坑圆度与扫描次数呈正相关性。在相同微凹坑密度下，与未处理试样相比，激光功率为6、10、16 W 时试样的自腐蚀电位分别向正移-33、40、26 mV，自腐蚀电流分别减少了91.93%、92.09%、91.19%。激光功率为10 W 时具有最好的抗腐蚀性能；在相同激光功率下，与未处理试样相比，微凹坑密度为1.5%、2.5%、5.0%时试样的自腐蚀电位分别向正移21、40、56 mV，自腐蚀电流分别减少了92.22%、92.09%、94.05%。在实验密度范围内，微凹坑密度越高，AZ31B镁合金表面的抗腐蚀性能越好。

In order to study the influence of laser-induced micro-dimple on electrochemical corrosion behaviors of AZ31B magnesium alloy, samples are processed with optical fiber laser to get specific microdimple. The surface profile, diameter and depth of the micro-dimple are characterized by Axio CSM 700 and the electrochemical polarization curves are investigated by electrochemical work station. The results indicate that with the increment of laser power, the depth and diameter of micro-dimple increase but ablation occurs around the micro-dimple. The diameter of micro-dimple does not change significantly while the roundness improves with the number of processing increasing. Comparing with the untreated specimen, the corrosion potentials are improved by -33, 40, 26 mV and the self-corrosion currents decrease to 91.93% , 92.09% , 91.19% with laser powers of 6, 10, 16 W respectively under the same micro-dimple density condition. A better corrosion resistance is obtained with laser power of 10 W. For the same laser power condition, the corrosion potentials are improved by 21, 40, 56 mV and the self-corrosion currents decrease to 92.22% , 92.09% , 94.05% with the micro-dimple densities of 1.5% , 2.5% , 5.0% respectively comparing with the untreated specimen. Besides, the increasing of micro-dimple density leads to a better corrosion resistance of AZ31B magnesium alloy in the density zone of the experiment.