Nonlinear macrolocalization of strain in hexagonal close-packed zirconium alloys

Abstract

Using laser speckle interferometry and surface profiling methods, the evolution of plastic strain localization under uniaxial tension of hcp zirconium alloys is studied. It is found that oscillatory instability observed at the parabolic stage of plastic flow in zirconium alloys arises when the specimen locally and nonuniformly changes shape. It is shown that the cross-sectional area of the deforming specimen decreases nonlinearly and is determined by the oscillatory variation of contraction and extension strains at the site of macrolocalization in the hardening-softening mode.