Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.347035
Title: Deformation studies on Fe 3.5 wt % Si single crystals by X-ray topography
Author: Dudley, Michael
ISNI:       0000 0001 3433 8366
Awarding Body: University of Warwick
Current Institution: University of Warwick
Date of Award: 1982
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Abstract:
For many years the Plastic Deformation of bcc metal crystals has formed the subject of numerous investigations comprising a wide range of experimental techniques. One of the more recent and novel of these techniques is Synchrotron White Radiation Topography. This is well suited for examination of relatively large areas of comparatively thick crystals, without the need for undesirably long exposure times (as encountered, for example, in conventional topography), typical values being of the order of seconds, making dynamic, in situ experiments feasible. In this study, Synchrotron White Radiation Topography was used to make in situ, dynamic observation of the evolution of slip bands in single crystals of Fe 3.5 wt % Si (of rectangular cross-section) with two different surface orientations under uniaxial tensile stress in the [Oil] direction. Both types of crystal were oriented for double slip, in one the primary Burgers vectors lying in the crystal surface, and in the other the primary Burgers vectors lying at an angle of 35° 16' with the surface. Slip morphology in particular, was found to be a sensitive function of surface orientation. The studies reported in this thesis form a continuation of the work reported in Miltat and Bowen ([32]), and demonstrate the usefulness of the technique in studies of this nature. Important information on the early stages of deformation and the progress of slip was obtained. In Chapter 1 a brief review of the type of work that has already been conducted on bcc metals is presented, with particular reference to Iron and its alloys with Silicon. Chapter 2 presents a description of the apparatus used throughout the work, including a detailed description of synchrotron X-ray sources, and the sophisticated direct imaging equipment essential for dynamic experiments. The basic experimental approach adopted is outlined in Chapter 3. Chapters 4 and 5 comprise a brief review of contrast theory in X-ray topography, and how this theory can be applied to interpret topographs. Experimental results are presented in Chapter 6, and these results are discussed in detail in Chapter 7. A brief description of the effect of stress on the magnetic domain configurations in the specimens is given in Appendix I. Details of a calculation conducted with J. Miltat ([225]) on the projective geometries of white beam topographs are presented in Appendix II. Results of detailed calculation of integrated intensities expected on the topographs are given in Appendix III.
Supervisor: Not available Sponsor: Science and Engineering Research Council ; Government of France
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.347035  DOI: Not available
Keywords: QD Chemistry
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