低粗糙度表面的连续激光抛光形貌演化机制研究  

Morphology Evolution Mechanism of Low⁃Roughness Surface Polished by Continuous Laser

作　　者：王梁 姜柯 范思远 黄锦榜 葛鸿浩 吴国龙 董刚 姚建华 Wang Liang;Jiang Ke;Fan Siyuan;Huang Jinbang;Ge Honghao;Wu Guolong;Dong Gang;Yao Jianhua(Institute of Laser Advanced Manufacturing,Zhejiang University of Technology,Hangzhou 310023,Zhejiang,China;College of Mechanical Engineering,Zhejiang University of Technology,Hangzhou 310023,Zhejiang,China;Collaborative Innovation Center of High-End Laser Manufacturing Equipment Co-Sponsored by Ministry and Province,Hangzhou 310023,Zhejiang,China)

机构地区：[1]浙江工业大学激光先进制造研究院,浙江杭州310023 [2]浙江工业大学机械工程学院,浙江杭州310023 [3]高端激光制造装备省部共建协同创新中心,浙江杭州310023

出　　处：《中国激光》2023年第12期143-156,共14页Chinese Journal of Lasers

基　　金：国家自然科学基金重点项目(52035014);国家自然科学基金(U2130122);浙江省公益技术应用研究项目(LGG20E050019)。

摘　　要：采用连续光纤激光器在氩气环境下对粗糙度为R_(a)=0.95μm的低粗糙表面进行激光抛光实验,通过光学显微镜和激光共聚焦显微镜对单道激光抛光熔池截面、抛光前后三维表面形貌及表面轮廓进行分析。研究结果显示:在其他参数不变的条件下,随着扫描速度的提升,单道连续激光抛光熔池两侧的咬边现象逐渐加重。随着激光功率的提高,由于单道抛光熔池不稳定,熔池表面的起伏现象逐渐加剧。当扫描线间距为0.02 mm时,连续激光多道搭接之间未重熔区域具有较低表面起伏值,粗糙度可降低至R_(a)=0.45μm。然而,激光单向扫描抛光后表面产生的波纹起伏会阻止粗糙度的进一步降低,采用正交扫描和未搭接区域回填扫描的策略,可对激光单向扫描抛光产生的波纹起伏进行重熔正交补偿,使粗糙度值由R_(a)=0.45μm进一步降低至R_(a)=0.048μm,较原始粗糙度下降95%。Objective Laser polishing,as a new type of surface treatment technology,offers the advantages of non-contact,high precision,high efficiency,and minimal pollution.Continuous laser polishing is usually referred to as laser macro polishing.The object to be polished possesses a high-roughness surface with undulations in the range of 10‒80μm.In contrast,a pulse laser is normally used for polishing low-roughness surfaces.However,the surface morphology and formation mechanism of the molten pool after continuous laser polishing of low-roughness surfaces have not been studied in detail.In this paper,samples with a low-roughness surface are polished by a continuous laser.The surface morphology of the molten pool after continuous laser polishing,as well as the mechanisms of single-pass and multi-pass overlapping polishing,are studied,which provide an optimized laser scanning strategy for continuous laser polishing technology.Methods Low-roughness austenitic stainless steel samples with an original surface roughness of R_(a)=0.95μm are used in this study.First,a metallographic microscope and a laser confocal microscope are used to analyze the size of the molten pool and the threedimensional morphology of the molten pool surface after continuous laser polishing using different laser process parameters to identify the optimal continuous laser single-pass polishing process parameters.Second,on the basis of single-pass polishing,the effects of line spacing and multi-pass overlapping polishing on the surface morphology are studied,and an optimized continuous laser polishing scanning strategy is determined.Finally,the hardness and element content of the cross section after continuous laser polishing are analyzed to determine the influence of continuous laser polishing on the surface properties.Results and Discussions In this paper,continuous laser polishing of a low-roughness surface is studied(Fig.1).Under the same laser energy density,with increasing laser power and scanning speed,the surface fluctuations of the molten pool

关 键 词：激光技术 连续激光抛光 表面粗糙度 表面形貌 扫描策略 

分 类 号：TG111.4[金属学及工艺—物理冶金] TN249[金属学及工艺—金属学]