Zn^(2+)和Co^(2+)对汽车件无镍常温磷化膜性能的影响  

Effect of Zn^(2+) and Co^(2+) on Performance of Ambient Temperature Phosphating Coating on Automotive Parts

作　　者：邱晨[1] 郝瑞[1] 廖杰[1] 刘娅莉[1] 

机构地区：[1]湖南大学化学化工学院,湖南长沙410082

出　　处：《材料保护》2008年第11期18-20,共3页Materials Protection

摘　　要：由于Ni2+污染环境,汽车磷化向无Ni或低Ni方向发展,采用扫描电镜(SEM)研究了Zn2+,Co2+浓度对常温低锌汽车磷化膜性能的影响,对磷化液中添加不同量Co2+所形成的磷化膜做了对比试验。证实Co2+能细化磷化膜的晶粒形态,同时使磷化膜晶粒由片状向柱状转变;耐碱蚀试验表明,当Co2+从0.084g/L增加到0.420g/L时,在碱液中15min后的失重量从1.07g/m2下降到了0.60g/m2,这表明磷化液中Co2+的加入能提高磷化膜耐碱性,有利于提高随后的电泳涂膜的附着力(均达到1级)和耐冲击性能。试验证明,在汽车常温磷化中采用Co2+取代Ni是一种可行的方式。The effect of the concentration of Co2+ ions on the performance of ambient temperature zinc - based phosphating coating was investigatedfor automotive application. Thus Zn - based phosphating coating was prepared at ambient temperature from the fluids containing Co2+ ions with different concentrations. The microstructureof the resulting phosphating coatings was analyzed using a scanning electron microscope. Results showed that the addition of Co2+ leded to reduce of size and refinery of phosphate crystal and transformation of the grains from plate - like to column - like as well. Moreover, the introduction of Co2+ in the phosphating bath also helped to improve the resistance to alkali of the phosphating coatings. Namely, the weight loss of the phosphating coating was reduced from 1.07 g/m2 to 0. 60 g/m2 when the concentration of Co2+ rose from 0.084 g/L to 0.420 g/L. At the same time, the inclusion of Co in the phosphating coatings helped to improve the adhesion to substrate and resistance to impact as well, indicating that it could be feasible, in ambient temperature zinc phosphati-zing for automotive application, to replace Ni with Co.

关 键 词：常温锌系磷化 ZN^2+ CO^2+ 无Ni 阴极电泳 汽车件 

分 类 号：TG178[金属学及工艺—金属表面处理]