Effect of pulse current on wear behavior of Ni matrix micro-and nano-SiC composite coatings at room and elevated temperature

• Published in: Tribology international 2019-04, Vol.132, p.50-61
• Main Authors: Lanzutti, A., Lekka, M., de Leitenburg, C., Fedrizzi, L.
• Format: Article
• Language: English
• Subjects: Abrasive wear; Abrasives; Chemical analysis; Coating effects; Crystallography; High temperature; High temperature wear; Mechanical properties; Microhardness; Microstructure; Morphology; Ni-SiC composite coatings; Organic chemistry; Protective coatings; Pulse current electrodeposition; Wear mechanisms; Wear rate; Wear resistance
• ISSN: 0301-679X; 1879-2464
• DOI: 10.1016/j.triboint.2018.12.011

This work presents the effect of the pulse-current on the wear behavior of Ni/nSiC and Ni/μSiC electrodeposits. The deposits microstructure and SiC content were investigated by means of microstructural, crystallographic e chemical analysis. The mechanical properties were evaluated through microhardness measurements. Ball-on-disc tests were performed at both room temperature and 300 °C. Wear rate and mechanisms were determined by morphological and microscopical characterization. The composite-coatings produced under pulse current present enhanced hardness and wear resistance, at both temperatures, linked to microstructural refinement and SiC content. The main wear mechanism observed was triboxidation, accompanied by abrasive wear mainly on the micro-composite coatings. •Ni-μSiC and -nSiC layers were electrodeposited under DC or PC at various frequencies.•The use of nanoparticles strongly refines the Ni microstructure.•The PC produces a lamellar structure and increases the codeposited μSiC amount.•The PC increases the wear resistance of all the composite coatings at R.T. and H.T.•The tribolayer is strongly related to the coatings microstructure.