STUDY OF THE SURFACE MICROSTRUCTURE OF LASER COATINGS MADE OF DIFFUSION-ALLOYED POWDERS BASED ON PRODUCTION WASTE

New powder compositions from dispersed metal waste and industrially produced water-atomized iron powder, cast iron grit production waste and sifted N70X18SR4 alloy shavings have been obtained and investigated using mono- and complex chemical-thermal treatment methods. New protective and hardening coatings from the above powders and their combinations have been obtained using laser cladding method. Based on microstructure analysis, it has been determined that all coatings are characterized by a non-porous “coating – substrate” fusion zone. In each coating, in the zone close to the “coating – substrate” interface, there are large dendrites with first-order axes directed perpendicular to the fusion zone, i. e. oriented in the direction of heat removal. As a result of the research, sufficiently high continuity, homogeneity and good mechanical properties have been established, which should ensure excellent durability and wear resistance of the coatings