The effect of shot peening on the initiation of fatigue cracks by fretting
Plain fatigue and fretting fatigue studies have been carried out on an Al - 4% Cu - 1% Mg alloy in various heat treated conditions. It has been determined that shot peening the surface results in substantial improvements in plain fatigue and fretting fatigue strengths. The major cause of the improve...
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University of Nottingham
1983
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| Online Access: | http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.346296 |
| Summary: | Plain fatigue and fretting fatigue studies have been carried out on an Al - 4% Cu - 1% Mg alloy in various heat treated conditions. It has been determined that shot peening the surface results in substantial improvements in plain fatigue and fretting fatigue strengths. The major cause of the improvement of these properties is the presence of compressive stresses that are induced in the surface by the shot peening process. Surface roughening and work hardening of the surface are also caused by the shot peening process but these have little or no effect on the fretting fatigue properties. The magnitude of the compressive stresses at the peened surface are around 200 - 250MPa and these result in the nucleation of subsurface cracks that run parallel to the surface during the fretting process . Debris with a characteristic spherical shape is produced on the faces of the subsurface cracks. Subsequent delamination allows the spherical debris to reach the specimen surface causing a reduction in the friction between the fretting members. |
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