Publication
Title
Microstructure of precipitates and magnetic domain structure in an annealed $Co_{38}Ni_{33}Al_{29}$ shape memory alloy
Author
Abstract
 The microstructure of a Co38Ni33Al29 ferromagnetic shape memory alloy was determined by conventional transmission electron microscopy (TEM), electron diffraction studies together with advanced microscopy techniques and in situ Lorentz microscopy. Rod-like precipitates, 1060 nm long, of hexagonal close-packed -Co were confirmed to be present by high-resolution TEM. The orientation relationship between the precipitates and B2 matrix is described by the Burgers orientation relationship. The crystal structure of the martensite obtained after cooling is tetragonal L10 with a (111) twinning plane. The magnetic domain structure was determined during an in situ cooling experiment using the Fresnel mode of Lorentz microscopy. While transformation proceeds from B2 austenite to L10 martensite, new domains are nucleated, leading to a decrease in domain width, with the magnetization lying predominantly along a single direction. It was possible to completely describe the relationship between magnetic domains and crystallographic directions in the austenite phase though complications existed for the martensite phase.
Language
English
Source (journal)
Acta materialia. - Oxford
Publication
Oxford : 2008
ISSN
1359-6454
Volume/pages
56:16(2008), p. 4470-4476
ISI
000259931300033
Full text (Publisher's DOI)
UAntwerpen
 Faculty/Department Research group Publication type Subject Affiliation Publications with a UAntwerp address