EFFECT OF WS2 POWDER DEPOSITION ON MODIFYING THE SURFACE OF Al 6061-T6 THROUGH ELECTRICAL SPARK APPROACH

Abstract

Aluminum 6061-T6 alloy is widely used in several manufacturing sectors like automotive, aerospace and marine industries owing to their unique characteristics of high strength to weight ratio, low density and supreme electrical and thermal conductivity. Some of the properties of Al 6061-T6, such as poor surface and tribological behaviors, make them unable to be used in critical parts. In this work, surface modification was performed for Al 6061-T6 using WS2 solid lubrication through the electrical spark deposition technique. The deposition was conducted by altering three different parameters, that is, powder concentration (PC), spark-on time (ST) and gap voltage (GV), based on the Box–Behnken design of response surface methodology. Effects of these deposition parameters were investigated on various surface modification aspects, including deposition rate, surface roughness (SR), microhardness and layer thickness. Results exhibit that the WS2 deposited surface significantly improved the surface characteristics. Material deposition rate predominantly increased with an increase in PC. Surface microhardness is enhanced by 9–20 times that of the base material. The lowest SR was attained at an intermediate level of PC with a low level of ST and GV. A minimum layer thickness of 32.12 [Formula: see text]m at intermediate PC and high ST with low GV was achieved. The elemental and structural analyses confirmed that the formation of intermetallics, such as WO2, WO3, Al2O3 and Al4C3, was formed during electrical spark deposition.