Effect of microstructure on the fatigue properties of Ti–6Al–4V titanium alloys

Through an analysis on microstructure and high cycle fatigue (HCF) properties of Ti–6Al–4V alloys which were selected from literature, the effects of microstructure types and microstructure parameters on HCF properties were investigated systematically. The results show that the HCF properties are strongly determined by microstructure types for Ti–6Al–4V. Generally the HCF strengths of different microstructures decrease in the order of bimodal, lamellar and equiaxed microstructure. Additionally, microstructure parameters such as the primary α (αp) content and the αp grain size in bimodal microstructures, the α lamellar width in lamellar microstructure and the α grain size in equiaxed microstructures, can influence the HCF properties.

► The effects of microstructure on fatigue properties were studied.
► Fatigue strength decreases in the order of bimodal, lamellar, and equiaxed microstructure.
► A method of choosing microstructure for fatigue property was established.
► Fatigue properties are functions of microstructural parameters.