PROPERTIES OF COATINGS AFTER MAGNETIC-ELECTRIC HARDENING AND LASER PROCESSING

One of the methods of restoration and hardening of worn surfaces of the working bodies of agricultural machines is the application of coatings and (or) hardening heat treatment. Magnetic-electric hardening (MEH) and laser methods of hardening are analyzed. Subsequent processing by a continuous laser of coatings formed after MEA was studied to eliminate such defects as high surface roughness and the likelihood of microcracks. from two-component alloyed powders based on Fe-5% V and Fe-Ti iron, FBKh-6-2 alloy on a special installation. The subsequent laser treatment of the coatings was carried out on a CO2 laser with a power of 1 kW. The change in the intensity of the process of magnetic-electric hardening and the transfer of powder material was experimentally established. The mechanisms of thermal phenomena that ensure the melting of particles of a ferromagnetic powder during magnetic-electric hardening, the formation of a coating and structural transformations in the surface layer are considered. It has been established that when modeling thermal processes from a fast-moving source, it is advisable to use a relation that describes the process of heat propagation from a point source moving fast along a half-space with an adiabatic boundary. It has been established using experimental studies that laser treatment of coatings formed after MEA significantly reduces the gradient of structural inhomogeneity, leads to the complete disappearance of microcracks, reduces the average thickness variation of coatings up to 1.2 times and the volumetric porosity of coatings up to 3 times. reduction of microstresses from 0.74% to 0.1%.