Papers by Keyword: Intergranular Slippage

Abstract: The method was developed for quantitative estimation of inputs to plastic deformation of crystallographic and non-crystallographic modes of slip by data of X-ray texture measurements. The texture analysis allows to split material into fractions, deformed by predominant operation of crystallographic and non-crystallographic mechanisms, differing in final orientations of grains. Whereas texture maxima in pole figures correspond to grains, deformed by means of crystallographic slip and having predictable final orientations, texture minima are formed by grains, whose deformation does not submit to crystallographic regularities and therefore their orientations are deflected from stable positions or even prove to be arbitrary. These effects are demonstrated as applied to semi-products from Zr-based alloys, subjected to the deformation treatment at temperatures of the (α+β)-region of Zr-Nb phase diagram.

Abstract: Abstract. Features of the texture development in Zr-based alloys under compression at tempera-tures of the (α+β)-region of the Zr-Nb phase diagram indicate that the plastic deformation shifts temperatures of phase transformations due to accompanying thermal effects and the decrease of lattice stability, whereas formation of the fine-grained structure by phase transformation promotes activation of the non-crystallographic deformation mechanism of slip by interphase boundaries.

Abstract: The deformation behavior of commercial Zr alloys with 1% and 2,5%Nb under compression at temperatures of the (α+β)-region of Zr-Nb phase diagram is considered on the basis of experimental data obtained by X-ray texture study of deformed samples. Mechanisms, responsible for plastic deformation of alloys by different temperature-rate regimes were determined on the basis of resulting textures. Among these mechanisms there are crystallographic slip and mutual displacements of crystallites along interphase boundaries. The latter mechanism sharply intensifies by grain fragmentation down to nanostructuring under conditions of α«β phase transformations. Texture features of deformed samples testify about interaction of plastic deformation with phase transformations and indicate that due to this interaction compression by optimal regimes promotes the utmost refinement of structure elements.

Abstract: Deformation behavior of Zr-Nb alloys under uniaxial compression, accompanied by phase transformations, is considered by the example of Zr-1%Nb and Zr-2.5%Nb alloys. Model samples were deformed at temperatures of β- and (α+β)-regions of the phase diagram Zr-Nb. Mechanisms, responsible for plastic deformation of alloys by different temperature-rate regimes, were determined on the basis of textures, arising in deformed samples. Among these mechanisms there are crystallographic slip in grains of β-Zr and α-Zr as well as mutual displacements of crystallites along interphase boundaries. The latter mechanism sharply intensifies under conditions of α↔β phase transformations and lies in the basis of superplasticity. An input of each mechanism into plastic deformation of material depends on the temperature-rate regime of compression and determines its anisotropy.