Effect of aluminium on deformation structure of highly stabilised β-Ti–V–Cr alloys

Alloys of Ti–(25–37)V–15Cr–(1–7)Al (wt-%) were compressed at temperatures in the range 25–600°C. The dislocation structure of the deformed alloys was studied using transmission electron microscopy (TEM). It was found that at room temperature, alloys with Al > 5% were very brittle and could not be deformed plastically. Alloys with 3–5%Al can be plastically deformed at room temperature but dislocations were present in bands. At a temperature of 400°C, superdislocations of 〈111〉 type, which were usually present in bands, have been observed in alloys with more than ∼3%Al additions. In contrast, a high density of wavy dislocations, which were identified as of ½ 〈111〉 type, were found in an alloy with 2%Al after deformation either at room or at elevated temperatures.