Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403

공학

한국표면공학회지 (36권2호 155-160)

Effect of Electrolysis Conditions on Hard Chromium Deposition from Trivalent Chromium Bath

경질용 3가 크롬전착에 미치는 전해조건의 영향

김대영;박상언;김만;권식철;최주원;최용;
Kim, Dae-Young;Park, Sang-Eon;Kim, Man;Kwon, Sik-Chul;Choi, Ju-Won;Choi, Yong;

한국기계연구원 표면연구부;선문대학교 재료화학공학부;
Department of Surface Engineering, Korea Institute of Machinery & Materials;Department of Materials & Chemical Engineering, Sunmoon University;

Abstract

The effect of the temperature, current density and deposit time on hard chromium deposition in trivalent chromium bath was investigated. Cathode current efficiency increased with increasing current density. Increasing bath temperature from $20^{circ}C$ to $50^{circ}C$, chromium deposits were produced in higher current density and the maximum current efficiency was increased. At the plating conditions of $40^{circ}C$, $30A/dmm^2$, the deposition thickness increased in proportion to increasing electrolysis time The rate is$ 90mu extrm{m}$/hrs. for 2 hours. Microhardness of chromium deposits increased with increasing bath temperature and decreasing current density, and it was constant with electrolysis time. All of bath conditions, microstructure of chromium deposits has nodular structure with some cracking pattern and nodule size increased with increasing deposit thickness.

Keywords

Trivalent chromium;Current efficiency;Deposit thickness;Hardness;Surface morphology;