New composite coatings, their structure and properties

The effect of structure and phase composition of composite coatings on their service properties under extreme working conditions (high temperatures and pressure, intensive wear by friction, external loads and corrosion environments) was considered. Here, the coatings of Al₂O₃-Ti; and Al₂O₃-Al systems and others, produced by applying the installation of a multichamber detonation of spraying, developed at the E.O. Paton Electric Welding Institute of the National Academy of Sciences (NAS) of Ukraine, were investigated. In order to evaluate the efficiency of the coatings being investigated under different service conditions, the analytical estimations of structure ↔ properties relations were used. It was shown that the greatest contribution to the properties of strength, ductility and crack resistance of the investigated coatings were made by: dispersion of grain and sub-grain structures, uniform distribution of forming strengthening phases of dispersed sizes in absence of lengthy and dense dislocation clusters, being the concentrators of local internal stresses (potential zones of incipience and propagation of cracks). (author)