中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 28 No. 1 January 2018 |
（1. State key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082, China; 2. College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China; 3. Hunan Electric Power Company, State Grid Corporation of China, Changsha 410000, China; 4. Petro China West-East Gas Pipeline Company, Shanghai 200122, China）
Abstract:Ni-W-P coatings were electrodeposited on copper substrates by pulse electroplating. Effects of electrolyte pH (1-3), temperature (40-80 °C), average current density (1-7 A/dm2) and pulse frequency (200-1000 Hz) on deposition rate, structure and corrosion resistance performance of Ni-W-P coatings were studied by single factor method. Surface morphology, crystallographic structure and composition of Ni-W-P coatings were investigated by means of scanning electron microscopy, X-ray diffractometry and energy dispersive X-ray spectroscopy, respectively. Corrosion resistance performances of Ni-W-P coatings were studied by potentiodynamic polarization and electrochemical impedance spectroscopy in 3.5% NaCl solution (mass fraction) and soil-containing solution. It was found that the pulse electroplated Ni-W-P coatings have superior corrosion resistance performance and the electroplating parameters significantly affect the structure and corrosion resistance performance of Ni-W-P coatings. The optimized parameters of pulse electroplating Ni-W-P coatings were as follows: pH 2.0, temperature 60 °C, average current density 4 A/dm2, and pulse frequency 600 Hz. The Ni-W-P coating prepared under the optimized parameters has superior corrosion resistance (276.8 kΩ) and compact surface without any noticeable defect.
Key words: pulse electroplating; Ni-W-P coating; corrosion resistance
