Wet-chemical removal of hard coatings from workpiece surfaces - comprises using hydrogen peroxide soln. stabilised by complex former e.g. potassium-sodium tartrate-tetra:hydrate

摘要

Hard coatings, such as TiN, TiAlCN, TiCN and CrN, are removed from tools for recoating by physical or chemical vapour deposition by a H peroxide soln., stabilised by complex formers. The complex former is K-Na-tartrate-tetrahydrate or Na gluconate. Using bath temp. and H peroxide concn. raised by more than 30% decrease removal time to less than 1 hr for 2 mn coatings. ADVANTAGE - The process does not alter original surface