【摘要】 磷化液中添加稀土可提高磷化效率和质量,目前未见有关稀土硝酸镧[La（NO₃）₃]在原位磷化应用中的报道。在以二苯基膦酸为原位磷化剂的原位磷化液中添加不同含量的La（NO₃）₃,在6061铝合金表面制成磷化有机涂层。通过极化曲线、电化学交流阻抗、全浸泡试验、扫描电镜（SEM）分析La（NO₃）₃含量对涂层性能、表面形貌的影响,并将添加La（NO₃）₃的原位磷化涂层与铬酸盐处理涂层、磷酸盐处理涂层进行比较。结果表明:稀土La（NO₃）₃盐作为促进剂显著提高了6061铝合金在3.5%NaCl溶液中的耐蚀性能,且添加质量分数1.0%稀土La（NO₃）₃制备的原位磷化有机涂层的性能最佳;加入稀土La（NO₃）₃有效增强原位磷化有机涂层与铝合金基体的结合力;添加了稀土La（NO₃）₃的有机涂层的表面平滑、均匀、致密,进一步印证了极化曲线和电化学测试的结果。更多还原

【Abstract】 Organic coating was prepared on the surface of 6061 aluminum alloy by adding different contents of rare earth lanthanum nitrate to in-situ phosphating solution of two phenyl phosphate. Polarization curves and electrochenical impedance spectroscopy（EIS） were used to investigate the effects of lanthanum nitrate content on the properties and surface morphologies of the organic coatings. Furthermore,the prepared coating was compared with the chromate coating and phosphate coating. Results indicated that the rare earth La（NO₃）₃improved the corrosion resistance of6061 aluminum alloy in 3.5%NaCl solution effectively as a phosphating accelerator. When 1.0%（mass ratio） La（NO₃）₃was added to in-situ phosphatizing solution,the prepared organic coatings had the best performance. Besides,the bonding strength between in-situ phosphatizing organic coatings and aluminum alloy substrate was enhanced by incorporating La（NO₃）₃. Moreover,the surface of organic coating with rare earth lanthanum nitrate was smooth,uniform and compact,which further confirmed the results of polarization curves and electrochemical tests.更多还原