This study is concerned with the effect of particles, which are too small to produce Particle Stimulated Nucleation, on recrystallization. A single crystal model system of internally oxidised copper-aluminium was deformed by rolling. The deformed and annealed structures were investigated both electron-microscopically and optically. Measurements of the stored energy of deformation were combined with measurements of the recrystallization kinetics by the use of anisothermal differential scanning calorimetry. The effect of particles on the mechanical properties of metals and the microstructural inhomogeneities produced during deformation in the single phase are reviewed. The literature concerning recrystallization is surveyed with emphasis on the possible sites for nucleation and the effects of a second phase. Comparison of the deformed structure of copper-alumina and copper revealed that cells form at lower strains in the particle-containing material. These cells are smaller than those found in copper and show alignment with {111} planes. Dynamic recovery at higher strains leads to the formation of a banded structure from these cells. Microbands were found at all strains, they increased in frequency and decreased in width as the strain increased. Misorientation measurements using STEM microdiffraction could find no evidence of a slip homogenizing effect due to the particles, in fact larger misorientations were found across cell boundaries in particle-containing material. Addition of particles raised the stored energy and this increase was greater at higher strains. A comparison of the recrystallization kinetics of particle-hardened and single phase material found complex behaviour in the former. Increasing the strain could lead to a change from complete suppression, to retardation, to acceleration of recrystallization in two-phase alloys. A model based on the properties of microbands and particle pinning is presented to account for these effects.

Thesis (Ph.D.)--University of Wyoming, 2007. / Title from PDF title page (viewed on June 22, 2009). Includes bibliographical references.

No description available.

Thesis (M.S.)--University of Wisconsin--Madison, 1961. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf 44)

Thesis (Ph. D.)--University of Wisconsin, 1967. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--Ohio State University, 2006. / Available online via OhioLINK's ETD Center; full text release delayed at author's request until 2007 Mar 24

No description available.

No description available.

A novel computer model of the evolution of columnar and equiaxed microstructure during alloy solidification has been developed. A control volume finite difference model of conduction heat transfer is applied to a two-dimensional domain bounded by a relatively cold mould. The initial condition is that of superheated liquid, and nucleation occurs either at the mould wall, leading to columnar dendritic growth, or within the bulk liquid, leading to the growth of equiaxed dendrites. The columnar front or the equiaxed grain boundaries are represented by computationally sharp interfaces, which separate liquid from partially solid alloy. Interpolation between discrete computational markers is employed to describe these interfaces, and a front-tracking technique is used to predict the evolution of the grain structure, via movement of the markers, across the fixed grid. The front velocity is determined via considerations of the kinetics of dendrite growth. The heat equation is fully coupled to the front-tracking algorithm by means of source terms which represent the evolution of latent heat due to the dendritic growth (advancing tips and thickening mushy zone). The model, applied to binary Al-Cu alloys, is computationally efficient. It predicts the variation of the extent of liquid undercooling ahead of the growing columnar front, and new metrics have been established to determine the likelihood of the formation of an equiaxed zone here. The employment of these metrics to establish the influence of heat extraction rate and alloy composition agrees with reports from the literature. The model does not distinguish between individual grains of the columnar zone, but it is shown that this is not an important limitation for most metal casting applications. Direct simulation of the nucleation and growth of multiple equiaxed crystals has been carried out, in which the nucleation and growth of individual grams can be observed via animation, and the influence of melt superheat and heat extraction rate on equiaxed solidification has been determined.

Thesis (Ph. D.)--Auburn University, 2008. / Abstract. Vita. Includes bibliographical references (p. 160-171).