Some considerations on the mitigation of fretting damage by the application of surface-modification technologies

摘要

contacting surfaces and it is intimatelyrelated to wear, corrosion and fatigue. Theintroduction of surface treatments or coatings isexpected to be an effective strategy against frettingdamage. This paper discusses the application of severaltypes of advanced surface-modification methods forthe mitigation of fretting damage, such as physical andchemical vapour deposition (PVD and CVD), ionimplantation, laser treatment and plasma nitriding, etc.Some coatings are effective in the mitigation of thefretting wear, whereas others are more effective underfretting fatigue conditions. The effects of surface-modification methods on fretting resistance areexplained using fretting maps. There are at least fivedifferent mechanisms in using surface-modificationmethods to increase fretting resistance: (1) inducing aresidual compressive stress; (2) decreasing thecoefficient of friction; (3) increasing the surfacehardness; (4) altering the surface chemistry; (5)increasing the surface roughness. Apart from this, theintrinsic properties of the coatings, such as theirdensity and mechanical and chemical properties as wellas the adhesion condition with the substrate, alsosignificantly affect the performance of the coatingsunder fretting conditions. Based on this rationale, acoating-selection method was proposed to select themost appropriate surface treatments or coatings tominimise the probability of fretting damage. Selectionof a process is guided primarily by identification of thefretting failure modes, and the ability to adjust andobtain the required surface properties, with a balancebetween the precise control of the surface properties and the process cost.