Plastic flow instability at the necking stage in zirconium alloys

Regular features in plastic-strain macrolocalization are examined at the parabolic stage of strain hardening in the é635 and Zircaloy-2 zirconium alloys. Instability of the plastic flow is observed, which is manifested as a periodic variation of space-time distributions of local strain as revealed by means of speckle interferometry. The data obtained are discussed within the framework of a synergetic model for the plastic flow evolution at the final stage. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 3, pp. 141–149, May–June, 2006.