Influence of substrate bias on structural and tribo-mechanical properties of pulsed magnetron sputtered TiN-WSx hard-lubricious coating. (July 2018)

• Record Type: Journal Article
• Authors: Banerjee, Tushar; Chattopadhyay, A.K.
• Is Part Of: Tribology international. Volume 123(2018)
• Page Start: 81
• Page End: 91
• Publication Date: 2018-07
• Subjects: Hard-lubricious coating -- Bias voltage -- Pulsed magnetron sputtering -- Tribological properties; Tribology -- Periodicals; 621.89
• DOI: 10.1016/j.triboint.2018.03.005
• Languages: English
• ISSNs: 0301-679X

Abstract

Abstract: Lubricious WSx was codeposited with hard TiN to improve tribological property of the latter. Effects of substrate bias on structural and tribo-mechanical properties of composite coatings were investigated. Tribologically favourable (002) orientation of WS2 diminished with increase in bias. Surface morphology became increasingly compact up to −70 V. Adhesion, hardness and tribological characteristics were strongly influenced by applied bias. At 0 V, low hardness and adhesion led to localized detachment and consequent lump formation of coating in pin-on-disc test. At −90 V, pulverisation of hard, brittle coating material was observed. Superior tribological performance at intermediate bias of −40 V has been discussed in light of balanced combination of WSx content, adhesion and hardness of the composite coating. Highlights: Effects of substrate bias on TiN-WSx hard-lubricious coating were studied. (W + S) wt.% and S/W at.% ratio decreased with increase in bias. Adhesion and hardness of coatings maximized at different levels of applied bias. At zero bias, the softer coating formed lumps in wear test. At high bias of −90 V, the harder and brittle coating pulverized.