The influence of heat treatment on the elastic and microplastic properties of ultrafine-grained titanium with variable content of impurities

Results of investigations of the influence of heat treatment at elevated temperatures on the elastic and microplastic properties of ultrafine-grained (UFG) titanium processed by severe plastic deformation are discussed. The samples were prepared from various batches of $\alpha$-titanium (VT1-0, Grade 4, and PT3-V) with different initial polycrystalline structures and impurity compositions. Experiments showed that significant changes in the structure (grain size), elastic properties, and microplasticity characteristics only took place in the $\alpha$-Ti grade of maximum purity (VT1-0). UFG titanium of Grade 4 and PT3-V showed much higher thermal stability of properties, which was probably related to the presence of large amounts of various impurities.