Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403


한국표면공학회지 (35권2호 93-100)

Investigation of the mechanism of Ni-P alloy deposition using by in-situ surface pH measurement during electrodeposition

음극표면 pH 측정에 의한 Ni-P합금의 전착기구 고찰


한국기계연구원 표면연구부;한양대학교 신소재공학부;
한국기계연구원 표면연구부;한양대학교 신소재공학부;


To better understand the codeposition mechanism of phosphorous, surface pH and potential of cathode were measured during electrodeposition of Ni-P alloys. The pH of cathode surface was measured using a flat-bottom glass pH electrode and a 500 mesh gold gauze as cathode. The cathode surface pH was increased with increasing the current density and always higher than the pH in the bulk solution. As a result of overplotting the surface pH and cathode potential on the Pourbaix diagram, it was found that cathode surface shift to the domain of predominant of $H_2$$PO3$-or $H_2$$PO_2$-. Additionally, new deposition mechanism was suggested that $H_2$ $PO_2$- and $H_2$$PO_3$- play important roles in the deposition reaction of Ni-P alloys.