Adhesive strength at the interface of the top coat of yttria stabilised zirconia (YSZ) and the bond coat depends on a number of technological factors. Some procedures are used to form YSZ layers with long service lives. They are based on "the concept of reduction", that is the use of partial zirconia reduction due to its dissociation under vacuum. YSZ dissociation facilitates the formation of free metal cations in it. In this case high adhesive strength results from diffusion processes which occur at the interface of the ceramic layer and the metallic bond coat. They make possible the formation of an interlayer. During YSZ condensation bond coating elements diffuse into the ceramic layer to the depth of up to 10 mum. The ceramic layers formed by the processes based on "the concept of reduction" feature high service lives at 1100 degreesC.