Investigation on microstructure and texture evolution of Ti–6Al–3Nb–2Zr–1Mo alloy during hot deformation

Abstract

Hot compression tests of Ti–6Al–3Nb–2Zr–1Mo alloy were conducted in the temperature range of 900 °C–1100 °C and strain rate range of 0.01–1s ^−1 . Based on the true stress – true strain curve, the calculated activation energy Q in α + β two-phase region and single- β phase region are 605.85 and 132.44 kJ mol ^−1 , respectively. The microstructure and texture evolution were analyzed by using EBSD technique. The continuous dynamic recrystallization (CDRX) and discontinuous dynamic recrystallization (DDRX) mechanisms are the two dynamic recrystallization (DRX) mechanisms of Ti–6Al–3Nb–2Zr–1Mo alloy deformed at 900 °C, and the latter is dominant. With the increase of temperature to 980 and 1020 °C, CDRX gradually weakens, and the DRX mechanism changes to be controlled by DDRX. The orientation distribution function (ODF) maps show that the initial texture gradually vanishes, and different textures are formed during hot deformation. DDRX behavior causes the decrease of the texture density of Ti–6Al–3Nb–2Zr–1Mo alloy deformed at 900 °C. However, the parallel precipitation of α laths rapidly increases the texture density of Ti–6Al–3Nb–2Zr–1Mo alloy deformed at 980 and 1020 °C.

Keywords

• Ti–6Al–3Nb–2Zr–1Mo alloy
• hot deformation behavior
• dynamic recrystallization
• texture evolution