Crystallographic texture evolution in Ti-35Nb alloy deformed by cold rolling

Abstract

This work presents the results of a microstructural characterization of the Ti–35Nb alloy deformed by cold rolling. Initially, samples of the Ti–35Nb (wt%) alloy were obtained by electric arc melting. After melting, these samples were solution heat-treated at 1000 C for 8 h and water quenched. The resulting microstructure was composed of b-phase (bcc) combined with orthorhombic martensite (a00). Samples were cold-rolled in multiple passes to reduce their thickness by up to 85% without intermediary annealing. They were then characterized by light optical microscopy, X-ray diffraction and Vickers hardness measurements. Young’s modulus was determined by ultrasonic methods and nanoindentation measurements. The texture evolution and orientation relationship between phases were studied by X-ray diffraction and electron backscatter diffraction (EBSD). The results reveal the presence of shear bands in the deformed samples, an orientation of the orthorhombic martensite phase in relation to the rolling direction, and variations of Young’s modulus in response to deformation. The textural results of the bphase show a typical bcc rolling texture with strong (110) fiber and weak (111) fiber. The intensity of the (110) fiber increases with deformation.