Influence of particle size and surfactants on uniformity and quantity of silicon carbide particles in electrodeposited nickel-silicon carbide coatings

碳化硅粒度及表面活性剂对Ni-SiC复合镀层中碳化硅含量及分布均匀性的影响

The electrodeposition of nickel-silicon carbide coatings on a copper electrode was done by mixing SiC particles in the nickel electrodeposition solution.The influence of surfactants and silicon carbide particle size on uniformity and quantity of silicon carbide particles in nickel-silicon carbide composite coatings was investigated.It was found that particle size affects the nucleation overpotential,with 40 nm silicon carbide nanoparticles more effective in promoting nickel nucleation than 500 nm particles due to an increase in active nucleation sites.In terms of surfactants,anionic surfactant sodium dodecyl sulfate(SDS)produced better dispersion of 40 nm silicon carbide particles than cationic surfactant cetyltrimethyl ammonium bromide(CTAB),but little difference was found between the two when 500 nm silicon carbide particles were used.Thus,although the suspension of silicon carbide particles can be improved and their co-deposition can be promoted with a cationic surfactant CTAB,it is less effective than an anionic surfactant SDS in terms of surface finish.

本文在电沉积镍的镀液中添加SiC颗粒于铜基体上制备Ni-SiC复合镀层,研究了表面活性剂种类和增强颗粒粒度对Ni-SiC复合镀层中碳化硅含量及分布均匀性的影响。SiC颗粒的粒度影响形核过电位,40 nm SiC颗粒比500 nm SiC颗粒提供更多成核活性点,且对于镍电结晶形核促进作用更明显。表面活性SDS对40 nm SiC颗粒的分散效果较CTAB更好,二者对500 nm SiC颗粒分散效果相似。CTAB从某种程度上增加了SiC颗粒的含量,但对于SiC颗粒的分散效果不佳,SiC颗粒仍有大量团聚,且通过阳离子表面活性剂CTAB所获镀层表面比较暗淡、粗糙。