Methods of coating and surface finishing articles made of metals and their alloys

US3969195A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Richard Dotzer · Nuremberg, DE
• Klaus Stoger · Nuremberg, DE

Key dates

• Filing date: Oct 26, 1972
• Grant date: Jul 13, 1976
• Expiry date: Oct 26, 1992

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C10N2050/10
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

Articles made of ferrous, non-ferrous and light metals and alloys thereof, e.g., aluminum, beryllium, magnesium, molybdenum, steel, tantalum, titanium, tungsten, vanadium and zinc and their alloys, are pretreated before coating and surface finishing in an anhydrous, inert, aprotic liquid, and subsequently electroplated with aluminum, cadmium, indium or zinc in an aprotic organo-metal electrolyte essentially free of molecular oxygen and water and, optionally, additionally finished by anodizing, chemical oxidation or diffusion. The pretreatment may be by erosion with finely-divided abrasive particles suspended in such liquid and impinged upon the surface of the article by hydraulic jetting, or with an aprotic liquid by the liquid-drop erosion method. Alternatively, the pretreatment may be by electrolytic action in a circuit where the article serves as the anode and is immersed in an anhydrous, aprotic electrolyte. Articles so pretreated and electroplated are thereafter more readily surface-finished or mechanically shaped.