X-ray investigations of ultrafine-grained metals processed by severe plastic deformation

Recent results of the development and application of the X-ray structural analysis for the investigation of metals, subjected to severe plastic deformation (SPD) are represented and discussed. The paper focuses on the analysis of the peculiarities of the ultrafine-grained structure and crystallographic texture, which were formed as a result of SPD in the studied metals (Cu, W, Mo, Ti) having different types of a crystal lattice. In frames of the Debye quasiharmonic approximation there have been established a considerable decrease in the Debye temperature (up to 82 K), an increase in the static (similar to30%) and dynamic (similar to50%) atomic displacements, a growth of the linear thermal expansion coefficient (3 times). There has been analyzed the contribution of the distorted grain boundary areas to the discovered changes of the atomic vibration spectrum characteristics in the investigated metals.