Similarity Laws in Laser Cladding of Cermet Coatings

Abstract

The influence of the laser beam parameters (power, motion velocity, and focus position) on the characteristics of the track being formed (size, elemental composition, and microhardness) is studied. If the difference in the laser radiation absorption coefficients in the heat conduction and keyhole regimes is taken into account, then the track sizes can be determined by a unified dependence on the energy parameter. The effect of the laser beam on the chemical composition and microhardness of cermet (WC-NiCrBSi) tracks is studied. Regardless of the track formation regime, these parameters are determined by a dimensionless parameter, which describes the degree of dilution of chemical substances. It is found that a track with the maximum mass fraction of tungsten and the greatest value of microhardness is formed at small values of the dimensionless parameter, which corresponds to the heat conduction regime. The microhardness of the deposited cermet structure is observed to be 4–5 times higher than the microhardness of the substrate material.