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

• Published in: Tribology international Vol. 143; p. 106002
• Main Authors: Sousa, Jurandir Marcos Sá de, Ratusznei, Francisco, Pereira, Milton, Castro, Richard de Medeiros, Curi, Elvys Isaías Mercado
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-03-2020; Elsevier BV
• Subjects: Abrasion resistance; Abrasion resistant alloys; Abrasion resistant coatings; Abrasion resistant steels; Abrasive wear; Chromium carbide; Chromium carbides; Coefficient of variation; Cooling cracks; Cracks; Dilution; Fiber lasers; Laser beam cladding; Lasers; Low carbon steels; Microhardness; Nozzles; Performance evaluation; Silicon base alloys; Substrates; Thermal gradient; Tribology; Cooling cracks; Abrasion resistance; Chromium carbides; Thermal gradient
• ISSN: 0301-679X; 1879-2464
• DOI: 10.1016/j.triboint.2019.106002

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.
•The microstructure phases characteristics varied according to the dilution.•Microhardness was 10% higher in coatings with higher CrC carbides concentration.•Microhardness showed a behavior inversely proportional to the k wear coefficient.•Higher dilution coatings had their abrasion resistance reduced by cooling cracks.•Better tribological results was mainly attributed to CrC carbides restraint action.