Fatigue properties of hot isostatically pressed Al–10Mg castings

Abstract

Constant amplitude fatigue tests have been carried out to assess the effect of hot isostatic pressing (HIP) on the fatigue properties of cast Al–10Mg (wt-%) alloy (AA 520.0). The results showed that HIP treatment can result in large increases in the fatigue life. At a test stress of 106 MN m−2 (60% of proof stress) the average number of cycles to failure increased by 300% following HIP treatment. The magnitude of the increase was significantly greater at a lower test stress of 84 MN m−2 (47% of proof stress). However, the scatter in the results from specimens fatigue tested at 106 MN m−2 following HIP treatment was higher, resulting in a reduction in the safe fatigue life value that could be used for design purposes. Fracture surfaces of these specimens were examined to correlate fatigue life with defect levels. The high scatter can be attributed to the presence of oxide inclusions in the material.MST/1621