Development and Characterization of TiO_2 and Carbon based Composite Coating for Wear Resistance Applications

Abstract

To abate frictional loss, emission and optimization of advance coatings is vital for piston rings, thick low friction environment friendly carbon coatings have been successfully deposited by using high velocity oxy-flame (HVOF). The present work evaluates the microstructure, surface morphology, tribological and mechanical properties of carbon-based composite coating for piston rings. FESEM+EDS, HRXED and Raman spectra confirm deposition of coating which exhibits typical laminar and molten structure. EDS confirms the presence of all coating elements on the surface. The cross section shows excellent mechanical bonding between coating and substrate. The experimental result shows that micro-hardness value of composite coating (CC) before wear test exhibits 550 HV. The micro-hardness value of samples CC 1, CC 2 and CC 3 after wear test was 590, 620 and 650 HV. The experimental results of hardness for composite coating shows that as the test condition of temperature ranging from 150 to 350oC, load from 50N and sliding velocity from 1 m/s respectively, increases hardness rapidly increases from 590 to 650 HV. The hardness was found to increase ~15% at test condition of 70N load, 3 m/s sliding velocity and 350oC temperature. The experimental result shows that the residual stress developed on the carbon based composite coating (CC) before wear test exhibits -132 MPa. The residual stress value of samples CC 1, CC 2 and CC 3 after wear test was -91, -45 and -3 MPa. The experimental results of residual stress for composite coating shows that as the test condition of temperature ranging from 150 to 350oC, l load from 50 N and sliding velocity from 1 m/s respectively, increases residual stress rapidly decreases from -91 to -3 HV. The residual stress was found to decreases ~97.7% at test condition of 50N load, 1 m/s sliding velocity and 350oC temperature. newline