Graduation Semester and Year

2018

Language

English

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Materials Science and Engineering

Department

Materials Science and Engineering

First Advisor

Unknown

Abstract

Cu-rich side of Al-Cu phase diagram has not been studied extensively as the Al-rich side. It is well established that a one-phase (a phase) exists at 300oC between the 82% Cu and pure Cu, and at the eutectic temperature (1032oC) between 86% Cu and pure Cu, a phase, when quenched from above 600oC and subjected to annealing below about 300oC, or deformation, show ordering effects in resistivity, heat capacity, diffuse X-ray, microstructure, and in mechanical properties. This has been studied to determine whether these effects are due to short-range or long-range ordered domain [1]. The present computational study is to assess the Cu-rich side of Al-Cu phase diagram for Cu concentration larger than 75%, and between 300K and 1000K. Molecular dynamics, Hybrid Molecular Dynamics/Monte Carlo, and DFT simulations are used to investigate the possibility of phase separation in this range of phase diagram. It is shown that a two-phase region exists below about 900K, and that phase separation takes place by nucleation and growth, and not by spinodal decomposition. Also, it is shown that these two phases are random FCC a solid solution, and intermetallic a2.

Keywords

Cu-rich, Molecular dynamics, Density functional theory, Nucleation and growth, Long-range order, Short-range order, Al-Cu phase diagram

Disciplines

Engineering | Materials Science and Engineering

Comments

Degree granted by The University of Texas at Arlington

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