Compressive responses of ultrafine-grained titanium within a broad range of strain rates and temperatures

•Effects of strain rate, temperature and grain size on the compressive behavior for UFG and CG titanium were comparatively studied.•Main contributions to yield and flow stresses of CP-Ti, including grain sizes, dislocation densities and concentration of interstitial impurities, are estimated.•The primary strengthening sources for CG titanium comes from interstitials, which contribute ∼64% of the yield stress. While grain boundary strengthening, dislocation interaction and interstitials contribute ∼38%, ∼32% and ∼30% of the yield stress of UFG-Ti, respectively.