Ma Junfei, Zhang Zhigang, Liu Yihan, Zhang Xiao, Luo Hongjie, Yao Guangchun
School of Metallurgy, Northeastern University, Shenyang 110819, China.
Materials (Basel). 2018 Sep 24;11(10):1810. doi: 10.3390/ma11101810.
A Pd-free activation pretreatment process was developed for electroless Ni-P plating on NiFe₂O₄ particles. The main influencing factors, including NiCl₂·6H₂O concentration, pH of electroless bath and temperature, were investigated. Microstructures of the coating layers were characterized by scanning electron microscopy. It was found that a more uniform and compact Ni-P coating layer was successfully formed by electroless plating via Pd-free activation pretreatment than Pd as sited plating. The coating layers plated by Pd-free activation pretreatment were thicker than those by the sensitization and activation pretreatment on average (9 vs. 5 μm). The new process did not need conventional sensitization or activation pretreatments, because the Ni particles dispersed uniformly on the NiFe₂O₄ substrate became catalytic activation sites for nickel electroless plating. Such improvement was beneficial to shortening the preparation process and reducing the production costs with the use of noble metal Pd.
开发了一种用于在NiFe₂O₄颗粒上进行化学镀Ni-P的无钯活化预处理工艺。研究了主要影响因素,包括NiCl₂·6H₂O浓度、化学镀液的pH值和温度。通过扫描电子显微镜对涂层的微观结构进行了表征。结果发现,与钯活化镀相比,通过无钯活化预处理进行化学镀成功形成了更均匀、致密的Ni-P涂层。无钯活化预处理镀覆的涂层平均比敏化和活化预处理镀覆的涂层厚(9μm对5μm)。新工艺不需要传统的敏化或活化预处理,因为均匀分散在NiFe₂O₄基底上的Ni颗粒成为化学镀镍的催化活化位点。这种改进有利于缩短制备工艺并降低使用贵金属钯的生产成本。