Influence of dislocations and second phases on the magnetostrictive behavior of iron-gallium and other iron alloy single crystals

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Title Influence of dislocations and second phases on the magnetostrictive behavior of iron-gallium and other iron alloy single crystals
Publication Type dissertation
Department Metallurgical Engineering
Author Saha, Biswadeep
Date 2012-08
Description Rare-earth-free Fe-Ga magnetostrictive alloys exhibit an excellent combination of large low-field magnetostriction, strength, ductility, wide operating temperature range, and low cost. Various observations in these and other α-Fe-based magnetostrictive alloys suggest that lattice strain modulations that are influenced by solute elements, near neighbor atomic environments around Fe atoms, coherent and incoherent precipitates, and structural defects such as dislocations likely play an important role in their magnetostrictive behavior. In the first part, the effect of dislocations on the magnetostriction of Fe-Ga single crystals was examined. The [001]- and [126]-oriented Fe-20 at.% Ga single crystal samples were deformed in a controlled way to introduce dislocation arrays with two different array geometries. Magnetostriction values showed a much lower decrease after deformation for the case of a [001]-oriented crystal, where eight different slip systems were operative and consequently eight different sets of dislocation arrays are expected. A drastic drop in magnetostriction measured along the sample axis is observed in the sample subjected to a small strain by deformation of a [126]-oriented crystal during which slip occurred on only one slip system. The nature of strain modulation introduced in this case was spatially asymmetric. The [126] deformation was accompanied by an acoustic emission during the formation of slip band.
Publisher University of Utah
Subject Dislocation; Gallium; Iron; Magnetostriction; Molybdenum; Second phases
Subject LCSH Iron alloys; Gallium alloys; Magnetostriction
Dissertation Institution University of Utah
Dissertation Name Doctor of Philosophy
Language eng
Rights Management Copyright © Biswadeep Saha 2012
Format application/pdf
Format Medium application/pdf
Format Extent 2,912,850 bytes
Identifier us-etd3/id/704
Source Original in Marriott Library Special collections QC3.5 2012 .S24
ARK ark:/87278/s6r78w10
Setname ir_etd
ID 194859
Reference URL https://collections.lib.utah.edu/ark:/87278/s6r78w10
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