AZ31B镁合金激光表面微凹坑效应及其电化学腐蚀行为

发布时间：2019-03-08 16:43

【摘要】：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 m V,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 m V,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。
[Abstract]:In order to study the effect of laser surface micro-pits on the corrosion resistance of AZ31B magnesium alloy, a micro-pit array was prepared on the surface of the material by using the fiber laser. The morphology, the diameter and the depth of the micro-pits were observed by a scanning microscope, and the dynamic potential polarization curves of the surface of the material before and after the preparation of the micro-pits were measured by using a double-unit electrochemical workstation. The results show that the diameter and depth of the micro-pits increase with the increase of the laser power, and the ablation occurs around the micro-pits; the diameter of the micro-pits is not significantly related to the number of scans, but the circularity of the micro-pits is positively related to the number of scans. In the same micro-pit density, the self-corrosion potential of the samples was 6,10 and 16 W, respectively, and the self-corrosion potential of the samples was 91.93%, 92.09% and 91.19%, respectively, when the laser power was 6,10, and 16 W. When the laser power is 10W, the best corrosion resistance is obtained; under the same laser power, the micropit density is 1.5%, 2.5% and 5.0%, respectively, the self-corrosion potential of the sample is increased by 92.22%, 92.09% and 94.05%, respectively, when compared with the untreated sample. The higher the density of the micropits, the better the corrosion resistance of the surface of the AZ31B magnesium alloy.
【作者单位】：江苏大学机械工程学院;
【基金】：国家自然科学基金(51405204,51175236) 中国博士后科学基金资助项目(2013M540417,2014T70477) 高等学校博士学科点专项科研基金(20123227110022) 江苏省科技支撑项目(工业)(BE2013097) 江苏省博士后科研资助计划项目(1401065B) 江苏大学高级人才启动基金(13JDG109)
【分类号】：TG146.22

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