Process for the preparation and coating of a surface

A process for the preparation and coating of a surface of a substrate by thermal projection, comprising:

• progressively subjecting a surface of a substrate to laser irradiation comprised of successive laser pulses thereby at least partially to eliminate a superficial contaminating film on the surface of the substrate and to modify the morphology of a subjacent surface of the substrate so that the subjacent surface has an increased roughness;
• projecting by means of a thermal projection device a deposit material on the surface thus prepared immediately after said preparation and in synchronism therewith so as to result in an overlapping of the impact zones of the laser beam and of the projected deposit material;
• and
• obtaining a coating by application of several superposed layers of deposit material by successive depositions, said coating being obtained by providing for a given zone before deposit of each new layer, a preparation and modification by laser beam of a deposited layer, such that with the continuous action of the laser during thermal projection, the successive preparation of each layer surface results in an improvement of the properties of the deposit and a compaction of the preceding layers.