High cycle fatigue properties of an aluminium alloy 7075 treated by Surface Mechanical Attrition Treatment (SMAT)

Abstract : In this work, the effects of SMAT on mechanical properties of an aluminium alloy 7075 under high cycle fatigue (HCF) are investigated. For this purpose, symmetric tension-compression loadings are imposed on specimens of different conditions including untreated, polished and SMATed states. The results of the fatigue tests are presented in the form of S-N curve. The fracture surfaces are observed using Scanning Electron Microscopy (SEM) to examine the damaging mechanisms. These preliminary results are qualitatively interpreted in terms of fatigue life and of crack initiation mechanism.