Role of interstitial atoms in the microstructure and non-linear elastic deformation behavior of Ti-Nb alloy

In order to clarify the effect of interstitial atoms on the non-linear elastic deformation behavior of the Ti-Nb alloy, the microstructure of (Ti-26Nb)-1.0O alloy was closely investigated by transmission electron microscope (TEM) and in situ X-ray diffraction (XRD) measurements. The < 1 1 0 >(beta)* rel rods and {111}(beta)* rel planes were observed in a reciprocal space for the (Ti-26Nb)-1.0O alloy. Their origin was {1 1 0}(beta)< 1 (1) over bar 0 >(beta) transverse type lattice modulation generated by oxygen atoms. Nanosized modulated domain structure (nanodomain) distributed homogeneously and randomly in the beta phase and acted as obstacles for the long-ranged martensitic transformation in the (Ti-26Nb)-1.0O alloy. The non-linear elastic strain of the (Ti-26Nb)-1.0O alloy was generated by the continuous increase in lattice distortion strain of the favorable nanodomain variant during tensile deformation. (C) 2012 Elsevier B.V. All rights reserved.