Plastic deformation of a Ti-6% Al-4% V alloy with a strong transverse-type crystallographic α-texture at elevated temperatures

The deformation behaviour of (αβ)-Ti with a very sharp texture is influenced by temperature, strain rate and the sense of stress. In this paper the plastic deformation of (αβ)-Ti is investigated in a temperature range between 295 and 1073 K in compression and tension along different directions of the sheet plane (0 °, 45 ° and 90 ° from the rolling direction (RD)). For this temperature range, two phenomena are observed: a dynamic strain ageing (DSA) and a asymmetry of the yield stress associated with the movement of 〈c + a〉 dislocations. Electron microscopy of specimens strained in uniaxial tension or compression along [0001] at 570 K shows 〈c + a〉 dislocations moving on 101 and 11–2 planes and an anomalous activity of 〈c + a〉 dislocations is observed on the whole range of orientation. We discuss the effect of interstitial solutes on the activity of the 〈c + a〉 dislocations between 500 and 750 K and the effect of the non-centrosymmetry for the 101 planes on the directional asymmetry of the yield stress associated with the 〈ca〉 movement.