WEAR-RESISTANT DETONATION COATINGS BASED ON CHROMIUM CARBIDE FOR GAS TURBINES

A systematic study of detonation deposition of wear-resistant coatings made of composite powders based on chromium carbide used to harden parts operating at temperatures up to 870^oC is carried out. An integrated analysis of the characteristics of coatings produced from powders of Russian and foreign manufacturers was carried out. A composite in the form of mechanical mixture and powders obtained by cladding and the Spray–Dry method are considered. Using a numerical code, the acceleration and heating of particles of the sprayed powder are calculated and the optimal spraying modes are determined. The hardness, porosity, wear resistance, and bond strength of the resulting coatings were considered. A comparative characterization of residual stresses has been carried out. The infl uence of the spraying distance in the range from 50 to 400 mm and of the inclination angle of the treated surface up to 60^o has been studied. It is shown that in the case of dual-fuel mixture spraying, the density and wear resistance of coating increase and residual tensile stresses are completely eliminated. The adhesion of the resulting coatings exceeds 150 MPa, and the abrasive resistance of the best coating is characterized by a specifi c wear of about 3 mm³ /1000 rpm according to the ASTM G65 standard, which is 5 times higher than the resistance of the alloys used for the manufacture of gas turbine parts.
   
Author:  I. S. Batraev, K. V. Ivanyuk, D. K. Rybin, V. Yu. Ul′yanitskii, A. A. Shtertser
Keywords:  detonation spraying, wear-resistant coatings, chromium carbide, microstructure, adhesion, residual stresses.
Page:  1677