摘要
为进一步提高AZ31B镁合金表面磷化膜的耐蚀性能,在磷化液中添加钼酸钠。研究了钼酸钠质量浓度对磷化膜的表面形貌、成分和耐蚀性能的影响,结果表明:随着钼酸钠质量浓度从0 g/L增加到1.4 g/L,磷化膜的元素组成未变,都以Zn、O和P元素为主,但Mo元素的质量分数呈先升高后降低的趋势,磷化膜先趋于平整致密而后变差,导致耐蚀性能先逐步改善而后下降。钼酸钠质量浓度为1.0 g/L时获得的磷化膜较平整致密,其溶液电阻和电荷转移电阻分别达到69.7Ω·cm^(2)、6.36×10^(3)Ω·cm^(2),耐点滴时间长达218 s,该磷化膜的耐蚀性能最好,主要归因于适量钼酸钠促进磷化膜更快形成并使磷化膜的致密性提高,有效阻碍腐蚀介质渗透,抵抗腐蚀能力增强。
Phosphating film was prepared on AZ31B magnesium alloy from the phosphating solution containing sodium molybdate in order to improve its corrosion resistance,and the influence of the mass concentration of sodium molybdate on the surface morphology,components and corrosion resistance of phosphating film was studied.The results showed that with the increase of the mass concentration of so‐dium molybdate from 0 g/L to 1.4 g/L,the elemental composition of phosphating film was unchanged,mainly composed of Zn,O and P,however the mass fraction of Mo increased first and then decreased,the flatness and compactness improved first and then worsened,leading to the gradual improvement of corrosion resistance and then decreasing.The phosphating film obtained with 1.0 g/L sodium molybdate was smooth and compact,of which the solution resistance and charge transfer resistance was 69.7Ω·cm^(2)and 6.36×103Ω·cm^(2),respectively,and the resistance time to copper sulfate corrosion reached 218 s.This phosphating film exhibited the best corrosion resistance,which was mainly attributed to moderate sodium molybdate promote faster formation of phosphating film and improve the compactness,which can effectively hinder the penetration of corrosive media and enhance the corrosion resistance.
作者
孟学林
梁金禄
尹丽
MENG Xuelin;LIANG Jinlu;YIN Li(Guangxi Vocational&Technical Institute of Industry,Nanning 530001,China;Beibu Gulf University,Qinzhou 535011,China)
出处
《电镀与精饰》
CAS
北大核心
2022年第8期1-6,共6页
Plating & Finishing
基金
广西高校中青年教师基础能力提升项目(2017KY1171)。
关键词
磷化膜
耐蚀性能
AZ31B镁合金
钼酸钠
phosphating film
corrosion resistance
AZ31B magnesium alloy
sodium molybdate
作者简介
通信作者:尹丽(1981—),硕士,副教授,研究方向:化学工程、材料工程,email:longjun_6666@126.com。
