Fretting involves contact between surfaces undergoing small cyclic
relative tangential motion. The resultant wear and initiation of fatigue cracks are
strongly influenced by the nature of the surface. Shot-peening is an established
surface treatment which produces both surface roughening and the development
of compressive stresses in the surface. If the material is susceptible to work
hardening it also produces surface hardening, since local plastic deformation
occurs. Experiments have been devised to separate these three effects in a
study on the behaviour of an Al-4Cu-1Mg age-hardening alloy. The results on
the fretting - fatigue behaviour of the alloy show that the residual compressive
stress has the greatest effect on retarding the propagation of fatigue cracks
initiated by fretting. The present investigation is designed to assess the effect of
the roughening produced by different levels of shot-peening on the fatigue and
fretting fatigue of an age-hardened aluminium alloy after removal of the residual
compressive surface stress. On removal of the stress by heat treatment, the
surface damage resulting from shot-peening is more damaging in plain fatigue
than the increase in roughness would suggest, due to the presence of incipient
cracks. These are less damaging in fretting fatigue because they are nearly
parallel to the surface and are closed up by pressure from the fretting pad.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.