Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403


공학

한국표면공학회지 (37권2호 92-98)

The Effect of Additives on the Current Efficiency and the Microstructure of Trivalent Cr Electrodeposits Plated in Flow Cell System

고속도금된 3가 크롬도금의 전류효율 및 조직특성에 미치는 첨가제의 영향

예길촌;서경훈;

영남대학교 재료금속공학부;

Abstract

The current efficiency and the microstructure of the trivalent Cr deposits plated in flow cell system were investigated according to additives in sulfate bath and current density. The current efficiency of the deposits plated in the formic acid complexed bath was noticeably higher than that of the deposits from glycine complexed bath. The current efficiency of the deposits from the complexed baths with boric acid buffer increased linearly with current density in the range of 60-100 A/dm$^2$, while that of the deposits from the baths with both Al sulfate and mixed buffers increased parabolically with current density. The nodular crystallite size of the deposits increased with current density, and the deposits plated in low current density region had relatively smooth surface appearance with fine grains. The structure of the deposits from the complexed baths with boric acid buffer changed from amorphous structure to crystalline one with strong (110)peak with increasing current density. The deposits from the baths with both Al sulfate and mixed buffers had generally amorphous structure.

Keywords

Trivalent Cr electrodeposit;Current efficiency;Microstructure;