Science China Technological Sciences

, Volume 61, Issue 4, pp 558–566 | Cite as

Microstructural characteristics of cold-rolled Zr-2.5Nb alloy annealed near the monotectoid temperature

Article

Abstract

A dual-phase Zr-2.5Nb alloy was rolled at room temperature to 50% reduction and then annealed at two temperatures (560 and 580°C) near the monotectoid temperature. X-ray diffraction, electron channeling contrast imaging and electron backscatter diffraction techniques were jointly used to characterize microstructural characteristics developed in the as-rolled and annealed specimens. Results show that plastic deformation occurs in both bulk α-Zr grains and thin β-Zr films during rolling, allowing large lattice strains to be accumulated in β-Zr and active dislocation slip (especially the prismatic 〈a〉 slip) to be initiated in α-Zr. During subsequent annealing at 580°C, the prior β-Zr films are transformed into submicron β-Zr particles, which lose coherency (the Burgers orientation relationship) with surrounding α grains. In the specimen annealed at 560°C, however, the prior β-Zr films are found to be decomposed into nanoscale β-Nb particles. In both the annealed specimens, the β-Zr and the β-Nb particles appeared to be linearly distributed along the rolling direction. Two types of α structures, i.e., small equiaxed crystallites formed by recovery of dislocation structures and coarse bamboo-like recrystallized grains, are revealed in the annealed specimens. Effective boundary pinning due to the dense β-phase particles is demonstrated to play a key role in forming such unusual bamboo-like grains.

Keywords

Zr alloy dual-phase microstructure rolling recrystallization electron backscatter diffraction 

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Copyright information

© Science China Press and Springer-Verlag GmbH Germany, part of Springer Nature 2017

Authors and Affiliations

  1. 1.College of Materials Science and EngineeringChongqing University of TechnologyChongqingChina
  2. 2.College of Materials Science and EngineeringChongqing UniversityChongqingChina

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