Brusylo I. Increase of the service life of aviation ground equipment by improvement of methods for restoration of parts of the shaft type

The thesis is devoted to improvement of procedures for maintenance of parts of the shaft type in aviation ground equipment. For such parts, whose working surfaces during production and maintenance are subjected to chemical-thermal treatment, cladding or microwave hardening, a science-based method of electric arc spraying as an alternative is proposed. Based on models of gas-dynamic and physical-chemical processes, it has been established that an increase in the velocity and temperature of the transporting gas jet and particles makes it possible to reduce the diameter of spray droplets as well as to increase the density and decrease oxidation ability of restored surfaces, which provides their optimal performance properties and service life. With applying special methods for mathematical planning of experiment, regimes for part restoration using the improved method of electric arc spraying were established, optimized and tested under laboratory and industry conditions. These studies made it possible to establish that the obtained adhesion strength is higher than that of analogs by 2-3 times (40 70 МPа), the porosity of formed layers is below 9 %, and the surface hardness varies within 40 HRC depending on that of the sprayed coating material.