Novel elastic deformation mechanism in multifunctional Ti-Nb alloy

In-situ high-energy X-ray diffraction was used to reveal a novel elastic deformation mechanism of the polycrystalline Ti-24Nb-4Zr-8Sn alloy under uniaxial compression. These experiments of polycrystal provide direct evidence on anomalous change in full widths at half maximum for {110}beta peak during elastic deformation, i.e. peak broadening during unloading and peak narrowing upon loading, which is attributed to the formation of stress-induced irreversible ? phase as clearly demonstrated in single crystal during compression. Difference in modulus between omega and beta phases induces different change in lattice strain causing the broadening and narrowing of diffraction peak near {110}(beta) where actually contains {1120}(omega) under different applied stress. This study offers new perspectives to investigate intrinsic mechanism on specific phase transformation during elastic deformation.