镍-磷-硫酸钡化学复合镀层的研制(英文)

Development of electroless Ni–P–BaSO_4 composite coatings

在由硫酸镍31g/L、次磷酸钠22g/L、乙醇酸30g/L、乙酸钠13g/L、二甲胺0.8g/L、全氟乙基碘化铵0.1g/L及重晶石(即硫酸钡)0～25g/L组成的稳定镀液中,采用化学镀的方法在低碳钢上制备了Ni–P–BaSO4复合镀层。其表面形貌采用扫描电镜进行分析,耐蚀性以动电位极化及电化学阻抗谱测试。镍–磷合金基体中掺入硫酸钡,提高了化学镀层的显微硬度。相对于纯Ni–P合金镀层,Ni–P–BaSO4复合镀层具有更小的磨损率。硫酸钡颗粒的存在使得复合镀层的耐蚀性明显降低。

Ni-P-BaSO4 composite coatings were prepared on mild steel by electroless plating from a stable bath containing nickel sulfate 31 g/L, sodium hypophosphite 22 g/L, glycolic acid 30 g/L, sodium acetate 13 g/L, dimethylamine 0.8 g/L, perfluoroethyl ammonium iodide 0.1 g/L, and barite （BaSO4） particles 0-25 g/L. The surface morphology of the composite coatings was analyzed by SEM, and the corrosion resistance by potentiodynamic polarization and electrochemical impedance spectroscopy. The incorporation of BaSO4 into Ni-P alloy matrix increases the microhardness of the electroless coatings. Ni-P-BaSO4 composite coating exhibits a distinctly small wear rate as compared with pure Ni-P alloy coating. The presence of barite particles in the deposit significantly reduces the corrosion resistance of the composite coatings.