Projection thermique de matériaux réactifs en vue de la formation de revêtements composites résistants à l’usure

Abstract

The dispersion of more than 20 vol. % submicrometer ceramic particles within a metallic matrix and the deposition of such a cermet to form a thick and lough coating presents problems. Most of the coating techniques have failed in attempting to homogeneously disperse very fine anti hard particles in large amounts while avoiding their decomposition or reaction with the metal matrix during the deposition process. A simple and efficient method has been developed for producing ceramic-containing composite coatings. It consists in synthesizing cermet-based materials and in depositing them by a rapid solidification process such as thermal spraying reactive powders comprising the basic reagents. These materials, with a microstructure of submicrometer ceramic particles, dispersed in a metallic matrix, exhibit good wear-resistant properties (abrasion and sliding wear). Finally, reactive core wire arc spraying is suggested as a flexible way to produce coatings containing up to 25 vol. % TiB2.