ELECTRODEPOSITION OF CHROMIUM ON ALUMINUM BASE SHEET

摘要

A method for the direct electrodeposition of chromium on the surface of a metal substrate, comprising the steps of immersing said metal substrate in a plating bath selectively constituted or water, chromic oxide and sulfuric acid in amounts to maintain a CrO3/SO4-2 weight ratio in the range of about 75 to 180; and exposing said immersed metal substrate in said plating bath to a plating current for at least 30 seconds characterised in that prior to the immersion of the metal substrate in the plating bath said metal substrate is immersed in a controlled temp. bifluoridecontaining grainer bath for at least 10 seconds and in that the plating current is 3229-10764 amperes/m2.