Effect of bead characteristics on the fatigue life of shot peened Al 7475-T7351 specimens
2020; Elsevier BV; Volume: 134; Linguagem: Inglês
10.1016/j.ijfatigue.2020.105521
ISSN1879-3452
AutoresNatália Ferreira, J.S. Jesus, J.A.M. Ferreira, C. Capela, J.D. Costa, António Castanhola Batista,
Tópico(s)Advanced machining processes and optimization
ResumoThe present work aims to analyse the effect of shot peening processing parameters, material and size of beads on the fatigue behaviour of aluminium alloy AA7475-T7351. A systematic study was carried out on the roughness, surface hardening, residual stress profiles and fatigue life. Fatigue tests were carried out under both three points bending (3 PB) and tensile loadings. For 3 PB tests it was concluded that shot peening does not introduce significant improvement on fatigue life and that the use of low size glass beads is potentially beneficial, with roughness being as or more important than residual stresses. All tensile treated specimens presented an improvement of fatigue life in comparison to the untreated specimens, particularly when the crack initiated internally. Internal crack propagation generates a conical fracture surface until transition to mode I propagation.
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