摘要
目的改善6061铝合金单一电化学抛光所存在的抛光表面不均匀、局部杂散腐蚀的问题。方法将同步激光辐照引入电化学抛光过程,以提高加工质量。利用激光共聚焦显微镜、SEM、EDS、XPS及XRD等测试手段对比研究了有无激光辐照下抛光表面粗糙度与形貌的演变过程、材料的去除情况以及元素组分与相组成变化规律,并对抛光前后试样的润湿与耐蚀性能进行了评估。在此基础上,进一步讨论了同步激光辐照对6061铝合金电化学抛光的影响机制。结果试样经单一电化学抛光处理后表面粗糙度由729 nm降低至276 nm,较基体减小62%。引入激光同步辐照后,粗糙度进一步降低至207 nm,较基体减小72%。相较于单一电化学抛光,同步激光辐照下所制备抛光表面的O元素含量下降,腐蚀坑和难溶物显著减少,SiO_(2)含量得到降低。这些结果共同表明抛光不均匀、局部杂散腐蚀的问题得到有效改善。此外,更低粗糙度、更少的局部腐蚀坑以及更高的润湿角,使得同步激光辐照下所制备的抛光试样具有更好的耐蚀性能。结论同步激光辐照通过提升离子输运效率加快钝化层溶解,改善电流密度分布状态以及减小不同物相间溶解速率差异来提高6061铝合金电化学抛光的表面质量。
Electrochemical polishing(ECP)is a common method to reduce the surface roughness of 6061 aluminum alloy components and enhance their smoothness.However,further improvement in the processing effect of the conventional ECP is limited by the crucial issues,including the uneven polishing surfaces and localized stray corrosion.Therefore,to address these issues,synchronous laser irradiation,also called laser composite electrochemical polishing(L-ECP),was introduced into the electrochemical polishing process in this study.Through confocal microscopy,SEM,EDS,XPS,and XRD,the polished specimens treated with and without laser irradiation were comparatively studied in respect of the surface roughness,morphological evolution,material removal,elemental composition changes,and phase composition.At the same time,the wettability and corrosion resistance of the polished specimens were evaluated.Based on these comprehensive analyses,the effect of synchronous laser irradiation on the electrochemical polishing of 6061 aluminum alloy was further discussed.The surface roughness of the polished specimens treated with L-ECP initially decreased and then increased as the laser power increased,with the optimal laser power identified as 30 W.Moreover,during the single-line processing experiment,both the ECP and L-ECP treated specimens attained their lowest surface roughness after 6 minutes of processing,and the L-ECP treated specimens exhibited better surface quality.Through the above process optimization,a mirror polishing process was realized during the subsequent overlapping processing experiments.The surface roughness of specimens decreased from 729 nm to 276 nm after the conventional electrochemical polishing,representing a 62%reduction compared to the substrate.With the introduction of laser irradiation,the surface roughness of the as-received specimen was further reduced to 207 nm,and a 72%decrease was achieved compared to the untreated specimen.By observing the evolution of surface morphology,it was found that the polished surface prepared by the L-ECP treatment exhibited a significant decrease in corrosion pits and insoluble residues compared with that prepared by the ECP treatment.Meanwhile,EDS results suggested that a reduction in oxygen content was detected on the L-ECP treated specimen.XPS analysis also confirmed that specimens treated by L-ECP exhibited lower relative content of reaction product SiO_(2)than the ECP treated specimen.The above results verified that auxiliary laser irradiation effectively resolved the issues of non-uniform polishing and localized stray corrosion.The XRD results indicated that the thermal effect of laser irradiation mainly affected the electrochemical reaction process and did not change the surface composition of the substrate.In terms of performance,the increment in contact angle was observed on the polished surface by L-PEC,which indicated the introduction of laser irradiation increased the surface hydrophobicity of the substrate by improving the quality of polishing.Both polishing processes improved the corrosion resistance of the substrate,as evidenced by the decrease in corrosion current density.The surface of aluminum alloy treated with laser composite electrochemical polishing was more resistant to corrosion than the surface of aluminum alloy treated with regular electrochemical polishing.This was because it was less rough,had fewer defects,and was more hydrophobic.In conclusion,laser irradiation enhances the surface quality of 6061 aluminum alloy during electrochemical polishing by improving ion transport efficiency to expedite passive layer dissolution,optimizing current density distribution,and minimizing dissolution rate discrepancies among various phases.
作者
王晔
张潇楠
吴国龙
杨珍珍
张群莉
张根
朴钟宇
姚建华
WANG Ye;ZHANG Xiaonan;WU Guolong;YANG Zhenzhen;ZHANG Qunli;ZHANG Gen;PIAO Zhongyu;YAO Jianhua(College of Mechanical Engineering,Zhejiang University of Technology,Hangzhou 310023,China;Institute of Laser Advanced Manufacturing,Zhejiang University of Technology,Hangzhou 310023,China;School of Mechanical and Electronic Engineering,Jingdezhen Ceramic University,Jiangxi Jingdezhen 333403,China;Collaborative Innovation Center of High-end Laser Manufacturing Equipment(National"2011 Plan"),Hangzhou 310023,China;Nuclear Power Institute of China,Chengdu 610041,China)
出处
《表面技术》
北大核心
2025年第23期208-222,共15页
Surface Technology
基金
国家重点研发计划(2024YFB4607101)
浙江省自然科学基金(LQ24E050017)
国家自然科学基金(52575544,U22A20199)。
关键词
激光辐照
电化学抛光
6061铝合金
表面粗糙度
形貌演变
laser irradiation
electrochemical polishing
6061 aluminum alloy
surface roughness
morphology evolution
