Publication
Title
Displacive-replacive phase transformation in a $Ni_{62.5}Al_{37.5}$ phase studies by HREM and microdiffraction
Author
Abstract
 The structure of the metastable Ni2Al phase, which has long been a matter of controversy, has been carefully re-examined by means of high-resolution transmission electron microscopy (HREM) and electron microdiffraction. First, it is concluded that theas-quenched NixAl100-x(60 less-than-or-equal-to x less-than-or-equal-to 65) material already exhibits a partial omega-type collapse in a one-dimensional fashion which and is consistent with the anomalous dip in the phonon dispersion curve. Ni2Al precipitates are formed on annealing by thermal decomposition of the high-temperature NixAl100-xB2 phase and still retain the small omega-type shuffle. The amount of displacement in the well developed Ni2Al phase was estimated to be between 20 and 50% of the ideal omega collapse; this was determined by means of a combined technique of HREM and microdiffraction together with dynamical calculations of HREM images and diffraction intensities.
Language
English
Source (journal)
Philosophical magazine: B: physics of condensed matter: electronic, optical and magnetic properties. - London, 1978 - 2002
Publication
London : 1993
ISSN
1364-2812
0141-8637
0958-6644
Volume/pages
67:5(1993), p. 673-689
ISI
A1993LF72000005
Full text (Publisher's DOI)
UAntwerpen
 Faculty/Department Research group Publication type Subject Affiliation Publications with a UAntwerp address