Characteristics of microstructure in composite surface layers

Heat spraying consists in manufacturing of a metal, cermetallic or ceramic coating on the surface of any product by means of special-purpose blowpipe for melting and spraying of the applied materials. The sprayed layers are typically characterized by low adhesion to the surface and low cohesion, which limits opportunities of wide application. Additional processing is performed in order to rebuilt the created coatings, by e.g. surface treatment by application of concentrated energy sources [1-16]. The purpose of this work was a cognitive analysis of structural effects which occur in the alloyed surface layer melted with three various types of heat sources - laser, plasma and TIG welding method. Surfaces of samples were previously covered with l00μm TiO2 ceramic layer. The investigations, carried out in order to correlate structural effects in the created surface layer, revealed differences between beams used during heat treatment, in consideration of both methodology and structural results of the process.