Evolution of Elastic Properties of Ti and Its Alloys due to Severe Plastic Deformation

The paper analyzes how the elastic properties of titanium and its alloys vary as their structure is transformed from coarse- to ultrafine-grained under severe plastic deformation. The analysis includes acoustic measurements of the elastic modulus of Ti materials with a piezoelectric composite oscillator over a wide amplitude range, a detailed examination of their microstructure by electron microscopy and electron backscatter diffraction, and estimations of their nanoporosity by small-angle X-ray scattering and their density by precision weighing before and after applying a high hydrostatic pressure (1.5 GPa). The results of the analysis show that such structural transformations can cause a noticeable change in the elastic properties of Ti materials due to dislocations, nanoporosity, high internal stress, and initial grain structure.