Hot rolling of binary Ti-Nb alloys Part 1: Evolution of microstructure and texture

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 a (cph) and small volume fraction of β (bcc) phases while the alloys Ti-12Nb and Ti-16Nb show the presence of a'' (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 inho-mogeneous [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 b phase in comparison to that of the alloy Ti-12Nb. © Carl Hanser Verlag GmbH & Co. KG.