Characterization of the Structure and Properties of Composite Powder Materials and Coatings

Abstract

Tribological materials and coatings are typical composite materials of heterogeneous structure: hard particles in a relatively soft matrix. For the modelling of wear of homogeneous bulk materials the models of plastic deformation and brittle fracture are developed. To use the model for wear calculation, the following parameters characterizing materials were found necessary: parameters of hardness distribution, shear energy density, characterizing material removal at plastic deformation, fracture toughness characterization of the brittle fracture mechanism and fracture probability parameter. The above mentioned materials characteristics were found, wear rates were calculated and experimentally determined. The comparison of wear rates of coating demonstrated that the used mathematical models for describing erosion wear are adequate. The calculated values of the wear rates of the given metal-matrix composite material differed from the experimental results of erosion wear tests at high impact angles about 3 – 4 times.