SYMPOSIA PAPER Published: 01 January 1996
STP16191S

Evolution of Microstructure in Zirconium Alloys During Irradiation

Source

X-ray diffraction (XRD) and transmission electron microscopy (TEM) have been used to characterize microstructural and microchemical changes produced by neutron irradiation in zirconium and zirconium alloys. Zircaloy-2, Zircaloy-4, and Zr-2.5Nb alloys with differing metallurgical states have been analyzed after irradiation for neutron fluences up to 25 × 1025 n.m-2 (E > 1 MeV) for a range of temperatures between 330 and 580 K.

Irradiation modifies the dislocation structure through nucleation and growth of dislocation loops and, for cold-worked materials in particular, climb of existing network dislocations. In general, the a-type dislocation structure tends to saturate at low fluences (< 1 × 1025 n.m-2). The c-component dislocation structure, however, may evolve over long periods of irradiation (for fluences >10 × 1025 n.m-2 in some cases).

The phase structure is also modified by irradiation. The common alloying/impurity elements, Fe, Cr, and Ni, are relatively insoluble in the α-phase but are dispersed into the α-phase during irradiation irrespective of the state of the phase initially containing these elements, i.e., metastable β-phase or stable intermetallic precipitate. The stable intermetallic particles may undergo structural changes dependent on their composition and the temperature. For the metastable dual-phase α/β-alloys (Zr-2.5Nb alloy), the β-phase structure is modified during irradiation, but the change is complex, being a combination of thermal decomposition and radiation-induced mixing.

Author Information

Griffiths, M
Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, Ontario, Canada
Mecke, JF
Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, Ontario, Canada
Winegar, JE
Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, Ontario, Canada
Price: $25.00
Contact Sales
Related
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Details
Developed by Committee: B10
Pages: 580–602
DOI: 10.1520/STP16191S
ISBN-EB: 978-0-8031-5343-1
ISBN-13: 978-0-8031-2406-6