Surface Coatings For Metal Objects Aluminium Alloys

Abstract

An electrolyte composition is disclosed for use in forming a protective coating on a metallic specimen by way of plasma electrolytic deposition, comprising an aqueous solution containing a charge carrier component together with an effective amount of carbamide, melamine, ammonium nitrate and/or similar nitrogen source. A system and method for applying a protective coating on a metallic specimen utilises a controllable power supply adapted to apply, for a predetermined period of time, a pulsed DC voltage of selected frequency and power characteristics sufficient to generate plasma electrolytic deposition on the surface of the object while the object is, in use, coupled to the power supply as the anode and immersed in the electrolyte solution. Advantageously, a sodium metaphosphate, such as sodium hexametaphosphate, can be used as the charge carrier component, wherein the electrolyte solution has a substantially neutral pH.

Dependencies are inferred from the claim text.