Tribological properties of TiSiVN coatings: The effect of the counterpart on the wear performance

Abstract

Self-lubricant coatings are a subject of continual research and improvements. In this research, the tribological performance of TiSiVN coatings produced by increasing V concentration is evaluated. The coatings were deposited by high-power impulse magnetron sputtering in deep oscillation mode, and were tested against three different counterparts (Al2O3, stainless steel and Titanium). The wear mechanisms were identified and the tribolayer was characterized to correlate with different specific wear rates and friction coefficient values. The coatings tested against Al2O3 balls displays a polishing type wear mechanism with some material adhered to the film wear track surface. When V is added to the reference film, V-O formed on the wear track has a beneficial influence by decreasing the friction and the wear of the coatings. For stainless steel balls, the wear track displays a mixture of severe abrasion and adhesion wear. Enclosure of hard particles at the softer stainless steel ball is the cause for the severe abrasion of the coating surface. This harsh abrasion removes the V-O from the contact and consequently decreases the efficiency of reducing friction coefficient and wear when compared to the tests against Al2O3 balls. For tests conducted against Ti ball, a strong adhesion of the material to the counterpart is observed. The adhered material protects the coatings from wear by giving rise to similar friction coefficient values irrespective of the coatings’ chemical composition.