无吸收层激光喷丸2024⁃T351铝合金耐腐蚀性能研究  

Corrosion Resistance of 2024⁃T351 Aluminum Alloy Processed by Laser Peening Without Coating

作　　者：夏雪峰 周建忠[1] 缑延强 黄蕾 孟宪凯[1] 黄舒[1] Xia Xuefeng;Zhou Jianzhong;Gou Yanqiang;Huang Lei;Meng Xiankai;Huang Shu(School of Mechanical Engineering,Jiangsu University,Zhenjiang 212013,Jiangsu,China)

机构地区：[1]江苏大学机械工程学院,江苏镇江212013

出　　处：《中国激光》2024年第12期104-113,共10页Chinese Journal of Lasers

基　　金：国家自然科学基金区域创新发展联合基金重点项目(U21A20135)。

摘　　要：为研究无吸收层激光喷丸工艺对铝合金耐腐蚀性能的影响,选用3 mm光斑直径与50%搭接率,分别在1.1 GW/cm^(2)与2.6 GW/cm^(2)的激光功率密度下,采用Nd∶YAG脉冲激光对2024-T351铝合金试样表面进行喷丸处理,结合表面形貌、化学成分、微观组织、物相、残余应力等,探索了不同激光功率密度下试样在质量分数为3.5%的NaCl溶液中的电化学腐蚀行为。结果显示:经过功率密度为1.1 GW/cm^(2)的无吸收层激光喷丸处理后,试样表面形貌与微观组织得到了改善,表面形成了凸起与孔洞交错的多级结构及2~3μm厚的致密重熔氧化层,深度方向出现晶粒细化现象,在100μm深度处出现最大残余压应力。此外,相较于未处理试样与2.6 GW/cm^(2)喷丸试样,1.1 GW/cm^(2)喷丸试样的腐蚀电流密度分别降低了97.30%与82.46%,同时腐蚀后试样表面保持着完整的具有多孔特征的微纳结构,展现出最佳的抗腐蚀性能。无吸收层激光喷丸工艺显著提高了2024-T351铝合金表面的耐腐蚀性能。Objective The 2024-T351 aluminum alloy,which belongs to the Al-Cu-Mg series and is extensively used in the aerospace industry,exhibits inadequate corrosion resistance that affects its reliability and service life.Laser peening(LP)has emerged as a novel surface treatment technology capable of enhancing both mechanical properties and corrosion resistance of 2024-T351 aluminum alloy.However,conventional LP requires an additional energy protective layer,limiting its practical industrial applications.LP without coating(LPwC)offers a promising alternative to conventional LP.The present study focuses on investigating the 2024-T351 aluminum alloy and employs a Nd∶YAG laser to perform LPwC treatment on the sample surfaces.By utilizing the experimental characterization techniques including surface morphology analysis,chemical composition examination,microstructure observation,phase analysis,and residual stress measurement,a comparative analysis of the corrosion behavior is conducted on the LPwC samples with laser power densities of 1.1 GW/cm^(2)and 2.6 GW/cm^(2)in the NaCl solution with mass fraction of 3.5%.The corrosion resistance mechanism of the LPwC process is also elucidated.Methods The experimental samples processed by the Nd∶YAG pulsed laser were selected from 10 mm×10 mm×2 mm square specimens.First,the surface and cross-sectional morphologies of the samples were observed using a scanning electron microscope(SEM).Second,the element compositions of the selected areas were analyzed by the energy dispersive spectrometer(EDS)attached to the scanning electron microscope.Third,the wetting performance of the samples was determined using a angular contact measuring instrument.Subsequently,the microstructure of the samples was examined with the SEM,and the X-ray diffraction(XRD)analysis provided information on the phase compositions of their surfaces.Furthermore,the X-ray stress tester allowed for measuring the residual stress distribution along the depth direction in these samples.Finally,electrochemical corrosion ex

关 键 词：激光技术 激光喷丸 2024-T351铝合金 电化学腐蚀 表面形貌 

分 类 号：TN249[电子电信—物理电子学] TG178[金属学及工艺—金属表面处理]