| abstract |
The invention relates to a method for forming surface coatings on a substrate by anodic oxidation, wherein the substrate contains, at least in those of its parts which are immediately sub-adjacent to its surface, at least one element selected from niobium, chromium, molybdenum, tungsten, titanium and vanadium, or a conducting compound containing such a first element, and at least one second element, different from the first, selected notably from silicon, aluminum, gallium, tantalum, uranium and molybdenum, either in the metallic state, if it constitutes itself a semi-conductor element, or even an insulator, or in the combined or alloyed state with at least one other element to form a semi-conductor compound, or even an insulator, said second element being flush at least in part at the surface of the substrate. n The invention also relates to the coatings themselves and which comprise a superficial layer and an inner layer of an oxide of the first element separated by an intermediate layer containing an oxide of the second element. |