Effects of particle size, particle volume fraction and matrix composition on the fatigue crack growth resistance of Al alloy/Al alloy + SiC_p bimaterials

Abstract

The fatigue crack growth resistance of Al alloy/Al alloy + SiCp bimaterials for crack growth perpendicular to the interface is affected by thermal residual stresses, elastic mismatch, plastic mismatch and direction of crack approach to the interface. When the crack approaches the interface from the composite side, the crack growth resistance is mainly controlled by the compressive residual stress near to the interface. Conversely, when the crack grows from the aluminium side towards the composite, the crack is shielded primarily by the elastic/plastic mismatch. In this work, the effects of particle size, particle volume fraction and matrix composition on the fatigue crack growth resistance of Al alloy/Al alloy + SiCp bimaterials have been assessed. These parameters can affect both the thermal residual stress profile and the elastic/plastic mismatch, and hence the effective crack tip driving force for crack extension is also affected.

Fatigue behaviour of friction stir welded AA2024‐T3 alloy: longitudinal and transverse crack growth

“…They are likely to affect mechanical and corrosion properties of the materials and therefore influence the in‐service performance of structural components. The effects of residual stresses on fatigue crack propagation have been reported by several authors such as Itoh et al , 1 Bussu and Irving 2 and Milan and Bowen 3,4 . Based on Parker's superposition principle, 5 they concluded that tensile residual stresses increase the crack growth rate due to increasing effective stress ratio ( R ′).…”

“…The effects of residual stresses on fatigue crack propagation have been reported by several authors such as Itoh et al, 1 Bussu and Irving 2 and Milan and Bowen. 3,4 Based on Parker's superposition principle, 5 they concluded that tensile residual stresses increase the crack growth rate due to increasing effective stress ratio (R ).…”