Laser Cladding of NiCrBSi/WC + W2C Composite Coatings

Abstract

This article presents the results of a study on the laser cladding of metal matrix composite coatings using an experimental custom-made powder composed of NiCrBSi matrix with 65 wt.% reinforcing hard particles of eutectic WC + W2C. The chemical and phase composition of the powder was designed to ensure high hardness, abrasion wear resistance at moderate dynamic loads and corrosion resistance at high temperature of the coatings. The influence of the basic processing parameters of the laser cladding, especially energy input, on the quality and single bead geometry, the dilution, share of the massive carbides in the matrix, and the fraction share of reinforcing carbides particles on cross-section of the clads, as well as hardness profiles and abrasive wear resistance, were analysed and presented. The microstructure of test coatings, chemical and phase composition were analysed by optical and scanning electron microscopes (OM, SEM), EDS and XRD spectrometers. It was found that the differences in the wear resistance of the coatings produced at different energy inputs of laser cladding were directly related to the share of the massive carbides WC + W2C in the metal matrix NiCrBSi. The tribological characteristics of the coatings were also studied and described. The test results indicate that the coefficient of friction for carbides is slightly higher than for the metal matrix, and therefore the greater the share of carbides, the higher the value of the coefficient of friction of the coating.

Influence of Surface Laser Treatment on Mechanical Properties and Residual Stresses of Titanium and its Alloys

“…Among many potential applications of laser sources for the manufacturing and modification of the properties of engineering materials, including cleaning, joining, cladding and cutting [57][58][59], remelting of metal surfaces plays a special role.…”

Resistance of Heterogeneous Metal Compositions to Fracture under Dynamic and Cyclic Loads

“…Although the mechanical properties of these materials in their initial state have been studied in sufficient detail, predicting the developing processes of destruction under various load conditions remains a difficult task because of the complexity of the structural state and numerous damage mechanisms [4]. With uniaxial loading of a layered material, the stress state of each layer may significantly differ from that of the neighboring layers [5] because of their unique mechanical and thermophysical properties, since the average physical and mechanical properties cannot be indicators of resistance to a specific destructive force factor, even for the surface layer of a composite material [6]. If the load is applied in two or three axes, the developed models for predicting the resistance [7,8] of layered metal composites cannot be effectively used for many cases of practical operation of multilayer structures.…”