2016 SVC TechCon

High Temperature Tribological Behavior of Ti Containing Multilayer MoS₂ Coating Against Aluminum Alloys (Room Wabash 2)

13 May 16
11:40 AM - 12:00 PM

Tracks: Protective, Tribological and Decorative Coatings

Speaker(s): Anindya Banerji, UNIVERSITY OF WINDSOR

The current study investigates the friction and adhesion mechanisms of a Ti incorporated MoS₂ (Ti-MoS₂) coating intended for use in elevated temperature engineering applications like hot forming, machining or upper compression ring. Pin-on-disk type tests were performed on Ti-MoS₂ against Al-6.5% Si (319 Al) and the steady state COF (µs) was measured at temperatures up to 400°C. The sliding friction tests were aimed towards testing the tribological stability of the Ti-MoS₂ coating at a temperature range (25°C to 400°C) where conventional adhesion mitigating hydrogenated diamond-like carbon (H-DLC) coatings fails. The µs of Ti-MoS₂ decreased from 0.11 at 25°C to a lowest of 0.05 at 200°C. The µs increased to about 0.13 at 350°C and further increased to 0.51 at 400°C. It was found that a lubricating MoS₂ rich transfer layer formed at the top of 319 Al surface was responsible for the low µs values observed till 200°C. The MoS₂ converted to the MoO₃ at temperatures beyond 200°C and provided lubrication till 350°C, confirmed using Raman and XPS analyses. The µs decreased by 95% in case of Ti-MoS₂ at the temperature range of 25 - 200°C compared to H-DLC.