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采用CO2连续激光对AM50镁合金表面进行熔凝处理。利用扫描电镜(SEM)、能谱分析(EDS)和X射线衍射(XRD)等手段对熔凝层的组织与成分进行了分析,通过在质量分数为3.5%的NaCl溶液中的电化学极化曲线测试和浸泡实验对激光熔凝层的耐蚀性能进行了检测。激光熔凝处理使镁合金的组织得到高度细化,组织与成分分布更加均匀,β相减少,Al及杂质元素的固溶度增加。极化曲线测试结果表明,激光熔凝表面的腐蚀电位较未处理试样提高了37mV,阳极腐蚀电流密度约降低了一个数量级;浸泡实验结果显示,激光熔凝表面腐蚀坑的出现时间和扩展速率明显慢于未处理试样,激光熔凝处理使镁合金的耐蚀性能有了明显提高。
CO2 continuous laser was used to melt the surface of AM50 magnesium alloy. The microstructure and composition of the fused layer were analyzed by SEM, EDS and XRD. The electrochemical polarization The corrosion resistance of laser cladding layer was tested by curve test and immersion test. The laser melting treatment makes the microstructure of magnesium alloy highly refined, the distribution of microstructure and composition is more uniform, the β phase is reduced, and the solid solubility of Al and impurity elements is increased. The results of polarization curves show that the corrosion potential of the laser fused surface is 37mV higher than that of the untreated sample, and the anodic corrosion current density is reduced by about one order of magnitude. The immersion test results show that the appearance time and the expansion rate Obviously slower than the untreated sample, the laser melting of magnesium alloy corrosion resistance has been significantly improved.