Structural properties of metastable phases in Zr–Nb alloys: III. The athermal Ω phase
- 作者：Aurelio ; G. ; Ferná ; ndez Guillermet ; A. ; Cuello ; G.J. ; Campo ; J.
- 关键词：Structural properties ; Metastable phases ; Zr&ndash ; Nb alloys ; Athermal Ω ; phase
- 刊名：Journal of Alloys and Compounds
- 出版年：2002
- 期刊代码：45_09258388
- 类别：ms
- 出版时间：March 14, 2002
- 卷：335
- 期：1-2
- 页码：132-138
- 文件大小：351 K
摘要
By means of high-resolution neutron diffraction experiments, a new study of the lattice parameters and other structural properties as well as the mass fraction of the Ω phase formed by quenching Zr–Nb alloys, has been made. With the present results and those from the recent neutron diffraction work by Benites and co-workers (J. Alloys Comp. 299 (2000) 183; 302 (2000) 192) reported on papers I and II of this series, an analysis is performed of the composition dependence of various key aspects of the diffusionless (‘athermal’) Ω phase transition in the Zr–Nb system. In particular, we discuss the misfit between the Ω particles and the parent bcc phase, the hexagonal to trigonal symmetry change occurring in Ω and the effect of the latter upon the shortest interatomic distance in this phase. The picture emerging from the present study is also used to investigate the interatomic distance correlation previously reported by Grad et al. (Z. Metallkd. 87 (1996) 726).