Study of microstructure and texture of heavily cold worked TiTaNb alloy and the effect of annealing

A Ti-5Ta-1.8Nb alloy has been subjected to severe deformation by means of unidirectional rolling at room and cryogenic temperatures. Under 85% room temperature rolling, the finest grains measured about 150 nm in width while those for 85% cryo-rolling were even finer, It was observed that the Vicker's hardness increased from 150HV for the starting material to about 260 HV for the 85% RT-rolled material and to about 280 for the 85% Cryo-rolled material, XRD studies showed positive lattice strain and also signatures of deformation texture. The deformed materials were studied in detail using transmission electron microscopy. Differential Scanning Calorimetry (DSC) studies showed that the recovery temperature was typically about 540°C and the recrystallisation temperature was about 610°0C Annealing studies were carried out at 500°C EBSD studies showed that the recrystallised grains were polycrystalline in nature and measured about 3μm and 1μm for the room and cryo temperature rolled samples, respectively. © 2009 Materials Research Society.