Formation of macro- and microstructure during the β→α transformation in zirconium single crystals

Autor: V. A. Sazonova, Yu. V. Khlebnikova, V. M. Umova, I. L. Solodova, L. Yu. Egorova, D. P. Rodionov, Yu. V. Kaletina, N. F. Vil’danova
Rok vydání: 2009
Předmět:
Zdroj: The Physics of Metals and Metallography. 108:254-262
ISSN: 1555-6190
0031-918X
Popis: Structure of an iodide zirconium single crystal prepared by zone melting has been studied by X-ray diffraction and optical and electron microscopy. It has been shown that the initial single crystal consists of macroscopic hcp packets, which are revealed by etching in crystal sections and differ in shape and dimensions (0.3–0.8 cm2). The orientation of each packet obeys the Burgers orientational relationships. Five different orientations of hcp packets of six possible variants have been found. The microstructure of each of such regions consists of a set of laths of the α phase of identical orientation separated by low-angle dislocation boundaries. The existence of structural heredity in the zirconium single crystal after a cycle of α→β→α transformations at the rate of heating and cooling on the order of 4–5 K/s has been confirmed. After quenching of a pseudo-single crystal of zirconium from a temperature of 960°C in a 10% NaCl solution, the packet structure of the α phase is retained, but the dimensions of the laths decrease severalfold.
Databáze: OpenAIRE
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