Influence of surface-coatings on titanium-alloy resistance to fretting fatigue in cryogenic environment

Fretting damage, also known as small amplitude oscillatory sliding motion, can lead to catastrophic failure in many industrial applications. The under standing of fretting fatigue and its reproduction in laboratory tests have enable us to evaluate the fretting resistance of homogeneous substrate. To reduce the damage caused by fretting fatigue increasing use has been made o f coatings or heat treatments which result in non homogeneous solids. From a theoretical point of view, ascertaining the mechanical behaviour of mater ials so modified is quite complex due to insufficient definition of the con tact parameters. This present study seeks to analyse a layered medium under going fretting fatigue and the improvement of its fatigue criterion. (C) 20 01 Elsevier Science Ltd. All rights reserved.