Nanomechanical and nanotribological properties of self-lubricating Ti/MoS2 nanocoating at nanoscale level

Abstract

Ti/MoS2 coating of thickness 99.79 nm was prepared by pulse laser deposition method on Al-Si substrate. Mechanical and nanotribological properties of Ti/MoS2 coating were obtained by carrying out nanoindentation, nanoscratch and nanowear tests at low loads. It was observed that Young's modulus and nanohardness of Ti/MoS2 coating decrease with increasing load. The coefficient of friction also decreases with the increase in sliding distance, which proves that Ti/MoS2 coating have self-lubricating property. The wear rate of Ti/MoS2 coating increases from 5.7 × 10−10 mm3/Nm to 2.1 × 10−9 mm3/Nm with the increase in load. Scanning probe microscope images of Ti/MoS2 coating shows the plastic flow of coating with no debris and cracks on the surface. It indicates that the abrasive wear is the main wear mechanism.