超声滚压镍基氧化铝涂层的微观结构及耐蚀性  

Microstructure and corrosion resistance of ultrasonically rolled nickel-based alumina coating

作　　者：高瑛琦 赵国勇[1] 许书铭 刘华一 臧珉 GAO Yingqi;ZHAO Guoyong;XU Shuming;LIU Huayi;ZANG Min(School of Mechanical Engineering,Shandong University of Technology,Zibo 255049,China)

机构地区：[1]山东理工大学机械工程学院,山东淄博255049

出　　处：《电镀与涂饰》2024年第12期68-73,共6页Electroplating & Finishing

基　　金：山东省自然科学基金重点项目(ZR2020KE060)。

摘　　要：[目的]研究超声滚压工艺对镍基氧化铝涂层的微观结构及耐蚀性的影响。[方法]采用超音速火焰喷涂工艺在Q235钢基体表面制备了Ni60/Al_(2)O_(3)涂层,随后进行超声滚压强化处理,分别利用扫描电子显微镜(SEM)、显微硬度计、X射线衍射仪(XRD)和电化学工作站,考察了超声滚压前后Ni60/Al_(2)O_(3)涂层的微观形貌、显微硬度、物相组成和耐腐蚀性能。[结果]经过超声滚压处理后,Ni60/Al_(2)O_(3)涂层的表面孔隙、裂纹等缺陷减少,变得光滑平整,粗糙度(Ra)由4.86μm下降为1.18μm,而且表层晶粒细化,形成了加工硬化层,使得涂层的显微硬度由545.6 HV提高到632.1 HV。与滚压前的Ni60/Al_(2)O_(3)涂层相比,滚压后的Ni60/Al_(2)O_(3)涂层在3.5%NaCl溶液中的腐蚀电位正移,腐蚀电流密度减小,说明耐蚀性得到增强。[结论]超声滚压工艺有效改善了涂层的表面品质,提升了涂层的显微硬度和耐腐蚀性能。[Introduction]The effect of ultrasonic surface rolling process on the microstructure and corrosion resistance of nickel-based alumina coating needs to be studied.[Method]Ni60/Al_(2)O_(3)coatings were prepared on the surface of Q235 steel by high-velocity oxygen-fuel spraying,followed by ultrasonic surface rolling for strengthening.The microscopic morphology,microhardness,phase constitution,and corrosion resistance of Ni60/Al_(2)O_(3)coating before and after ultrasonic surface rolling were studied by using scanning electron microscope(SEM),microhardness tester,X-ray diffractometer(XRD),and electrochemical workstation.[Result]After ultrasonic surface rolling,the pores,cracks and other defects on the surface of Ni60/Al_(2)O_(3)coating were reduced and the coating surface became smooth and flat with a decrease of roughness(Ra)from 4.86μm to 1.18μm.The surface grains were refined to form a work-hardening layer,which increased the microhardness of the coating from 545.6 HV to 632.1 HV.As compared with the as-sprayed one,the ultrasonically rolled Ni60/Al_(2)O_(3)coating had a positively shifted corrosion potential and a smaller corrosion current density in 3.5%NaCl solution,indicating that the corrosion resistance of Ni60/Al_(2)O_(3)coating was enhanced after ultrasonic surface rolling.[Conclusion]The ultrasonic surface rolling process effectively improves not only the surface quality but also the microhardness and corrosion resistance of Ni60/Al_(2)O_(3)coating.

关 键 词：超音速火焰喷涂 镍基氧化铝涂层 超声滚压 微观结构 硬度 表面粗糙度 耐蚀性 

分 类 号：TG174.4[金属学及工艺—金属表面处理]