Abrasion resistance of Ni-Cr-B-Si coating deposited by laser cladding process

Ni-Cr-B-Si alloy deposited by laser cladding has its tribological performance evaluated. Deposition parameters selection is a difficult task. In this work, Ni-Cr-B-Si coatings were deposited by a fiber laser source with a coaxial powder nozzle on low carbon steel substrate. Microstructure, microhardness and abrasive wear tests were performed. Results showed coatings with good surface adhesion. Microhardness was 10% higher in coatings with higher concentration and phase size of chromium carbides. Volumetric loss and wear coefficient showed 10% variation between the coatings. Coatings with different thermal gradients showed different dilution levels, affecting their abrasion resistance. The better tribological performance was obtained for coatings with lower cooling cracks density and higher volumetric fraction of carbides, which both mitigated wear micromechanism action.