Abstract
In order to investigate the effect of electroless nickel (EN) coating on fretting fatigue, rotating bending fatigue tests were carried out by clamping contact pads to fretting fatigue specimens. Comparing with the data generated under rotating bending fatigue conditions assessed fretting behaviour of the alloy. The material for the fatigue specimens was 2014-T6 aluminium alloy, and that for the pads was AISI 4140 steel. Fretting fatigue tests were carried out at initial contact pressures of 100 MPa in air. The fretting produced a reduction in fatigue strength of aluminium alloy. Results show that EN coating could yield satisfactory improvement in fretting fatigue response of the substrate. This improvement was associated with higher strength of the coating as compared to the substrate and with the development of compressive residual stresses and beneficial effect of surface roughness on the coating.

Key words
coating, aluminium alloy, fretting fatigue properties, fractographic analysis

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