Fracture mechanics approach to fretting fatigue behaviour of coated aluminium alloy components

Abstract

This article analyses the effect that different coatings have on the fretting fatigue behaviour of aluminium alloy mechanical components. To this end, a set of fretting fatigue tests of coated and uncoated specimens was carried out. The contact pads in the tests had a spherical surface, and a condition of partial slip was always maintained. The materials employed were aluminium alloy 7075-T651; coatings of molybdenum bisulphide, modified with tungsten carbide, MoS2–WC; and a commercial treatment known as Nituff®, which is a hard, anodized coating containing particles of polytetrafluoroethylene. The experimental results are discussed, and an analytical model based on fracture mechanics was applied to estimate the experimental fatigue lives obtained in the tests.