基体预处理对稀土转化膜耐蚀性能的影响  

Influences of Substrate Pretreatments on Anticorrosion Properties of Rare Earth Conversion Coatings

作　　者：张军军[1,2] 桑延霞[1] 叶建山[2] 李文芳[3] 

机构地区：[1]广东药学院医药化工学院,广东中山528458 [2]华南理工大学化学与化工学院,广州510640 [3]华南理工大学材料科学与工程学院,广州510640

出　　处：《材料工程》2014年第5期46-52,共7页Journal of Materials Engineering

基　　金：粤港关键领域重点突破(佛山专项)专项基金资助项目(2008Z012);广东省重大科技专项(产业共性技术)基金资助项目(2009A08025002);广东省大学生创新创业训练计划项目(1057312016);广东药学院2012年学生课外科研立项资助项目(109)

摘　　要：为了优化转化膜的预处理工艺和耐蚀性能,选用不同的预处理工艺制备了系列转化膜。通过盐雾实验评价了预处理工艺对转化膜耐蚀性能的影响,获得两种较优工艺(4#和8#)。采用动态极化曲线和电化学阻抗谱方法研究了经4#和8#预处理后转化膜在3.5%(质量分数)NaCl溶液中耐腐蚀性能的变化;借助扫描电子显微镜(SEM)、能谱(EDS)和润湿角测试仪,系统研究了4#和8#预处理工艺对成膜前后表面的形貌、成分和润湿性的影响;利用涡流测厚仪、显微硬度计和摩擦磨损试验机研究了4#和8#预处理工艺对转化膜生长速度、表面硬度和耐磨性的影响。结果表明,较佳的预处理工艺使铝合金表面阴极点适当暴露分布均匀、润湿性好、成膜速度适中,生成的转化膜致密完整、膜层更厚,耐蚀性更好;研究显示8#是较佳预处理工艺。To optimize the preparation process and anticorrosion properties, the conversion coatings were prepared with different pretreatment processes. The influence of pretreatment processes on anticorrosion properties of conversion coatings was investigated via salt spray test. Two optimal pretreatment processes （4^# and 8^# ） were obtained. Measurement of polarization curve and electrochemical impedance spectra （EIS） was used to study the corrosion resistance of film on Al alloy in 3.5% （mass fraction） NaCl solution. The morphology, elemental composition and wetting angle of the surface of uncoated and coated film after pretreatment were characterized by scanning electron microscopy （SEM）, energy-dispersive spectroscopy （EDS） and wetness angle measuring instrument, respective- ly. The conversion coatings forming speed, surface hardness and tribological property were investiga- ted by means of eddy current thickness meter, microhardness tester and frictional wear testing ma- chine. The results show that the pretreatment significantly affects the thickness, the completeness and the density of film by means of the wetting ability and negative points distribution of surface and also affects the corrosion resistance of conversion coatings. The research results show that 8~ is an op- timal pretreatment.

关 键 词：预处理 阴极点 润湿角 耐蚀性 

分 类 号：TG174.45[金属学及工艺—金属表面处理]