Initial Stages in the Evolution of the Structure of a Zirconium Pseudo-Single Crystal During Shear Deformation under Pressure

摘要

The structural-phase transformation in a pseudo-single crystal of zirconium during deformation on Bridgman anvils is studied by X-ray spectroscopy with synchrotron radiation. The angles of rotation in Bridgman anvils is varied from φ = 0° (deformation by upsetting, е = 0.2) to φ = 45° (е = 4.6). It is demonstrated that the α-phase lattice is compressed at the value of true strain e = 4.6. On the contrary, the ω-phase arising in the process of deformation under pressure shows a tendency to stretching. This behavior can probably be explained by low atomic density and strong anisotropy in terms of the atomic density of the planes and series of the ω-phase. It has been determined that the structure of the baric ω-phase arising during deformation under the deformation conditions ranging from e = 0.5 to e = 4.6 undergoes no textural changes. The formation of groups of planar defects in the ω-phase is a mechanism for the compensation of elastic stresses during the α→ω lattice transformation under conditions of high quasi-hydrostatic pressure.