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T. S. Lundy

Bio: T. S. Lundy is an academic researcher. The author has contributed to research in topics: Fick's laws of diffusion & Diffusion layer. The author has an hindex of 1, co-authored 1 publications receiving 403 citations.

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TL;DR: In this paper, the diffusion coefficients of Al26 and Mn54 in aluminum have been determined between 450° and 650°C. The exact solution to Fick's second law for the appropriate boundary conditions was used in treating the data.
Abstract: Diffusion coefficients of Al26 and Mn54 in aluminum have been determined between 450° and 650°C. Low specific activities of the isotopes necessitated use of a thick layer technique. The exact solution to Fick's second law for the appropriate boundary conditions was used in treating the data. Temperature dependence of the diffusion coefficients may be expressed by the following equations: DAl26=1.71 exp−(34 000/RT)DMn54=0.22 exp−(28 800/RT).

413 citations


Cited by
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TL;DR: In this paper, a review of the fabrication, microstructure and mechanical properties of in situ metal matrix composites reinforced with in situ ceramic phases is presented, with particular attention paid to the mechanisms responsible for the formation of the in situ reinforcements.
Abstract: During the past decade, considerable research effort has been directed towards the development of in situ metal matrix composites (MMCs), in which the reinforcements are formed in situ by exothermal reactions between elements or between elements and compounds. Using this approach, MMCs with a wide range of matrix materials (including aluminum, titanium, copper, nickel and iron), and second-phase particles (including borides, carbides, nitrides, oxides and their mixtures) have been produced. Because of the formation of ultrafine and stable ceramic reinforcements, the in situ MMCs are found to exhibit excellent mechanical properties. In this review article, current development on the fabrication, microstructure and mechanical properties of the composites reinforced with in situ ceramic phases will be addressed. Particular attention is paid to the mechanisms responsible for the formation of in situ reinforcements, and for creep failure of the aluminum-based matrix composites.

1,474 citations

Journal ArticleDOI
TL;DR: In this paper, the mechanical behavior of crystalline solids at elevated temperatures is discussed, including the creep properties of metals, solid solutions and two phase alloys, and the properties of two-phase alloys.

832 citations

Journal ArticleDOI
TL;DR: In this article, the diffusion coefficients of several transition elements (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn) and a few non-transition elements (Mg, Si, Ga, and Ge) in fcc and liquid Al are critically reviewed and assessed by means of the least-squares method and semi-empirical correlations.
Abstract: The diffusion coefficients of several transition elements (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn) and a few non-transition elements (Mg, Si, Ga, and Ge) in fcc and liquid Al are critically reviewed and assessed by means of the least-squares method and semi-empirical correlations. Inconsistent experimental data are identified and ruled out. In the case of the elements, for which plentiful experimental data are available in the literature, the least-squares analysis gives rise to the activation energies and pre-exponential factors in an Arrhenius equation. For the elements with limited experimental data or no data at all, the diffusion parameters are estimated from two semi-empirical correlations. In one correlation, the logarithmic pre-exponential factors are plotted against the activation energies for various elements in Al. In the other correlation, the activation energies are shown as a function of valences relative to Al. The diffusion coefficients calculated by using the evaluated diffusion parameters agree reasonably with the reliable experimental data. The proposed semi-empirical correlations are used to predict the diffusion coefficients of a few elements in liquid Al. A satisfactory agreement between the predicted and measured diffusion coefficients is obtained.

693 citations

Journal ArticleDOI
TL;DR: In this article, the authors derived a model for the onset of the Portevin-Le Chatelier effect in substitutional alloys, based on the solute locking of dislocations temporarily arrested at obstacles in the glide path.

570 citations

Journal ArticleDOI
TL;DR: In this article, a statistical model of point defect disorder in ordered compounds is presented and applied to Ti3Al and TiAl using input data generated with embedded-atom potentials.

544 citations