Hot rolling of binary Ti–Nb alloys Part 1: evolution of microstructure and texture

Abstract

Abstract This work describes the development of texture during hot rolling of three binary alloys, namely Ti-8Nb, Ti-12Nb and Ti-16Nb. The alloys have been unidirectionally hot rolled at 800°C and air cooled. The alloy Ti-8Nb consists of the α (cph) and small volume fraction of β (bcc) phases while the alloys Ti-12Nb and Ti-16Nb show the presence of α n (orthorhombic) and small volume fractions of β phases in as-cast and hot rolled conditions. The Ti-8Nb alloy exhibits nearly c-type texture in terms of basal pole figure in 40% hot rolled condition with a strong and inhomogeneous [0001]⊩ND fibre. Subsequent rolling reductions change texture and weaken the fibre present in 40% hot rolled specimen. The Ti-12Nb alloy exhibits c-type texture in 60% hot rolled specimen with a strong [001]⊩ND fibre. The overall texture of 80% hot rolled specimen is weak and different in terms of basal pole figure. The development of texture during hot rolling of the alloy Ti-16Nb is different from that of Ti-12Nb alloy even though the texture of 80% hot rolled specimens of both the alloys are nearly the same. The high overall intensity of texture in alloy Ti- 16Nb in the 80% hot rolled specimen can be attributed to the presence of a large volume fraction of β phase in comparison to that of the alloy Ti-12Nb.