Abstract: A metal surface is now described having enhanced adhesion of subsequently applied coatings. The substrate metal of the article, such as a valve metal as represented by titanium, is provided with a highly desirable surface characteristic for subsequent coating application. This can be initiated by selection of a metal of desirable metallurgy and heat history, including prior heat treatment to provide surface grain boundaries which may be most readily etched. In subsequent etching operation, the surface is made to exhibit well defined, three dimensional grains with deep grain boundaries. Subsequently applied coatings, by penetrating into the etched intergranular valleys, are desirably locked onto the metal substrate surface and provide enhanced lifetime even in rugged commercial environments.

Abstract: A method for the electrolytic pin plating of a steel plate using an insoluble anode, said anode being an insoluble electrode comprising a corrosion-resistant metal substrate having provided thereon a coating containing a platinum group metal or an oxide thereof, said anode being enclosed with a diaphragm.