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dc.contributor.authorLong, Feien
dc.date2015-02-27 14:39:43.741
dc.date.accessioned2015-03-02T19:02:35Z
dc.date.available2015-03-02T19:02:35Z
dc.date.issued2015-03-02
dc.identifier.urihttp://hdl.handle.net/1974/12770
dc.descriptionThesis (Ph.D, Mechanical and Materials Engineering) -- Queen's University, 2015-02-27 14:39:43.741en
dc.description.abstractZirconium alloys have been widely used in the CANDU (CANada Deuterium Uranium) reactor as core structural materials. Alloy such as Zircaloy-2 has been used for calandria tubes; fuel cladding; the pressure tube is manufactured from alloy Zr-2.5Nb. During in-reactor service, these alloys are exposed to a high flux of fast neutron at elevated temperatures. It is important to understand the effect of temperature and irradiation on the deformation mechanism of zirconium alloys. Aiming to provide experimental guidance for future modeling predictions on the properties of zirconium alloys this thesis describes the result of an investigation of the change of slip and twinning modes in Zircaloy-2 and Zr-2.5Nb as a function of temperature and irradiation. The aim is to provide scientific fundamentals and experimental evidences for future industry modeling in processing technique design, and in-reactor property change prediction of zirconium components. In situ neutron diffraction mechanical tests carried out on alloy Zircaloy-2 at three temperatures: 100˚C, 300˚C, and 500˚C, and described in Chapter 3. The evolution of the lattice strain of individual grain families in the loading and Poisson’s directions during deformation, which probes the operation of slip and twinning modes at different stress levels, are described. By using the same type of in situ neutron diffraction technique, tests on Zr-2.5Nb pressure tube material samples, in either the fast-neutron irradiated or un-irradiated condition, are reported in Chapter 4. In Chapter 5, the measurement of dislocation density by means of line profile analysis of neutron diffraction patterns, as well as TEM observations of the dislocation microstructural evolution, is described. In Chapter 6 a hot-rolled Zr-2.5Nb with a larger grain size compared with the pressure tubing was used to study the development of dislocation microstructures with increasing plastic strain. In Chapter 7, in situ loading of heavy ion irradiated hot-rolled Zr-2.5Nb alloy is described, providing evidence for the interaction between moving dislocations and irradiation induced loops. Chapter 8 gives the effect on the dislocation structure of different levels of compressive strains along two directions in the hot-rolled Zr-2.5Nb alloy. By using high resolution neutron diffraction and TEM observations, the evolution of type <a> and <c+a> dislocation densities, as well as changes of dislocation microstructure with plastic strain were characterized.en
dc.language.isoengen
dc.relation.ispartofseriesCanadian thesesen
dc.rightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.en
dc.subjectLattice strainen
dc.subjectPlastic deformationen
dc.subjectTEMen
dc.subjectZirconiumen
dc.subjectNeutron diffractionen
dc.subjectNuclear materialen
dc.subjectDislocationen
dc.titleCharacterization of Deformation Mechanisms in Zirconium Alloys: Effect of Temperature and Irradiationen
dc.typethesisen
dc.description.degreePhDen
dc.contributor.supervisorDaymond, Mark R.en
dc.contributor.departmentMechanical and Materials Engineeringen
dc.degree.grantorQueen's University at Kingstonen


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