Tuesday, 15 May 2018
Ballroom 6ABC (Washington State Convention Center)
Nickel-cobalt alloys are important coating materials due to their magnetic properties [1-2],
wear resistance [3-4] and electrocatalytic properties [5]. Their deposition from sulfamate
electrolytes has many advantages including low internal stress, homogenous deposition at
high current densities, high current efficiencies and higher hardness as compared to the
conventional Watts electrolyte [6]. A statistical experimental design was used to study the
effects of boric acid and nickel chloride concentrations, bath temperature and applied current
density on nickel coatings in sulphamate baths. After the optimization of the electrolyte
composition, effects of pH and Co additions to the electrolyte were investigated. The coating
thickness and its distribution were measured by XRF techniques. Microhardness, surface
morphology and internal stress of coatings were also determined. It was found that Co
addition to the electrolyte and operation at higher pH yielded deposits of higher Co content
and enhanced hardness up to a certain point.
wear resistance [3-4] and electrocatalytic properties [5]. Their deposition from sulfamate
electrolytes has many advantages including low internal stress, homogenous deposition at
high current densities, high current efficiencies and higher hardness as compared to the
conventional Watts electrolyte [6]. A statistical experimental design was used to study the
effects of boric acid and nickel chloride concentrations, bath temperature and applied current
density on nickel coatings in sulphamate baths. After the optimization of the electrolyte
composition, effects of pH and Co additions to the electrolyte were investigated. The coating
thickness and its distribution were measured by XRF techniques. Microhardness, surface
morphology and internal stress of coatings were also determined. It was found that Co
addition to the electrolyte and operation at higher pH yielded deposits of higher Co content
and enhanced hardness up to a certain point.
References
[1] A. Karpuz, H. Kockar, and M. Alper, J. Mater. Sci. Mater. Electron., 24 (2013) 3376-3381.
[2] G. Chatzipirpiridis, E. Avilla, O. Ergeneman, 50 (2014) 10-12.
[3] L. Xuewu, X. Yunhua, Q. Yi, and S. Lilong, Integr. Ferroelectr., 152 (2014), 144-151.
[4] L. Wang, Y. Gao, Q. Xue, H. Liu, and T. Xu, Appl. Surf. Sci., 242 (2005) 326-332.
[5] C. Hu, C. Tsay, and A. Bai, Electrochim. Acta, 48 (2003) 565-572.
[6] M. Saitou, S. Oshiro, and S. M. Asadul Hossain, J. Appl. Electrochem., 38 (2008) 309-313.