Development of substructure in Zry-4 during LCF at 874K

I ALVAREZ; A ARMAS; R VERSACI

JOURNAL OF MATERIALS SCIENCE

Springer

Año: 1990 vol. 25 p. 2454 - 2458

0022-2461

Transmission electron microscopy techniques were used to study the substructure developed in Zircaloy-4 during strain controlled Low Cycle Fatigue (LCF) test at 873 K. A complete microstructural analysis on samples cycled with a total strain range of 0.01 and total strain rate 2 x 10-3s -1 was made at a different number of cycles. This study revealed that the dislocations arranged themselves into a band structure which remains essentially constant since the first cycle up to fracture. This substructure stability agrees with the stress response observed of this alloy at 873 K. A mechanism to account for the observed structure is proposed