镀液温度对电化学制备Ni-SiC纳米复合镀层微观结构的影响

Effect of Bath Temperature on Microstructure of Ni-SiC Nanocomposite Coating by Electrochemical Deposition

在不同镀液温度下直流电沉积制备Ni-SiC纳米复合镀层,利用X-射线衍射仪(XRD)、扫描电子显微镜(SEM)和能谱仪(EDX)对镀层的相组成、表面形貌、成分等进行表征,考察镀液温度对镀层的微观形貌、晶体生长和镀层中SiC含量等影响。结果表明:随着温度升高,Ni-SiC晶粒从无序取向渐变为(220)择优取向,到70℃时(220)面的晶面织构系数达到最大值;镀层中纳米SiC含量随着温度的升高先增大后减少,在60℃时达到最大值;纳米SiC微粒的加入可抑制镍晶的晶粒生长,从而细化晶粒,并使镍晶产生晶格畸变;Ni-SiC纳米复合镀层的表面形貌随温度的升高,表面颗粒更加细化和均匀。

Ni-SiC nanocomposite coatings were electrodeposited in Watt＇s solutions with different bath tem- peratures through DC electrochemical method. The effects of bath temperature on the microstructure, crystal growth and SiC content in the coatings were investigated by X-ray diffraction （XRD）, scanning electron mi- croscopy （SEM）, energy dispersive spectrometer （EDS）. The results show that the Ni grain orientation grad- ually changes from disorder to （220） preferred orientation, and obtains the highest texture coefficient at 70 ~C with increasing bath temperature. SiC content in the coatings first increases and then decreases with the in- crease of the bath temperature, and SiC content attains the maximum at 60 ~C. The addition of particles re- strains the growth of the Nickel crystals, resulting in grain refinement and lattice distortion. As the bath tem- perature increases, the particles on coating surface become much finer and the coating becomes much smoot- her.