Effect of Fly Ash Composition on Electrodeposited Nickel-Fly Ash Composite Coatings on Aluminium Alloy 7075 Substrate

The nickel-fly ash (Ni-FA) composite coatings were deposited on zincated aluminium alloy 7075 (AA7075) substrate by using electrodeposition technique. The electrodeposition process was carried out for 1 hour at 40°C under the current density of 3 A/dm2 in nickel-citrate bath containing various composition of fly ash (FA) particles at 10, 20, 30, 40 and 50 g/l. The produced composite coatings were characterized using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). Microhardness and wear of Ni-FA composite coatings were also investigated in this study. The co-deposition of FA particles leads to significant increase in hardness and wear resistance.