Electrodeposition bath including chromic acid, sulphate, boric acid, a fluosilicate and an alkali metal carbonate

Abstract From the Canadian patent

A wear-resistant article comprises a zinc base metal having a substantially continuous, hard chromium skin layer on at least one surface thereof and a chromium-enriched subsurface layer of the zinc base metal situated immediately below the chromium skin layer. The chromium-enriched subsurface layer has a gradually decreasing chromium content in a direction inwardly away from the skin layer and is at least as thick as the skin layer. The wear-resistant article of this invention is produced by direct electrodeposition of chromium onto the zinc base metal from a self-regulating bath under controlled conditions. The chrome plating solution includes chromic acid sulphite ions, alkaline …