Deformation mechanisms of Ti–6Al–4V alloy with a martensitic microstructure subjected to oligocyclic fatigue

Abstract The objective of this work is to characterise the deformation modes when Ti–6Al–4 V alloy with α ′ martensitic structure is subjected to oligocyclic fatigue at various strain amplitudes. It is believed that, unlike pure titanium single crystals at room temperature, {1101} twinning occurs in the α ′ martensitic microstructure, because of the factors, such as the prior existence of dislocations or α ′/ α ′ interfaces, which may reduce the activation energy required for the nucleation of {1011} twins.