Influence of potassium iodate on chromium deposition

Chromium plating finds not only decorative but also functional applications. Generally chromium deposits are obtained from electrolytes with an approximate ratio of 100:1 of chromic acid to sulphuric acid. The Self Regulating High Speed (SRHS) chromium plating electrolytes, which are often employed for hard chromium plating though of higher efficiency have the disadvantages of cathodic etching and higher corrosivity. These are mainly due to the presence of a fluorine compound as a bath constituent. In this paper we report the results of experiments carried out with nonetching electrolytes but containing sulphate and potassium iodate. Different concentrations of chromic acid, sulphate and potassium iodate were used and current efficiency, rate of build-up, throwing power, deposit nature and microhardness were evaluate