Pakistan Research Repository

COMPUTER SIMULATION OF POINT DEFECT TWIN BOUNDARY INTERACTIONS IN FACE CENTERED CUBIC METALS

Ghafoor, Abdul (1993) COMPUTER SIMULATION OF POINT DEFECT TWIN BOUNDARY INTERACTIONS IN FACE CENTERED CUBIC METALS. PhD thesis, Islamia University, Bahawalpur.

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Abstract

A new method has been established to compute the variants of point defect clusters depending on their symmetry. Results are presented for close-packed clusters of up to five point defects in cubic crystals. Interesting relations among the variants of point defect clusters in two and three dimensional lattice structures have been noted. Computer simulation techniques have been employed to determine the relaxed structures and energies of some planar defects using many-body potentials developed by Ackland et al. (1987). The structures of some low index twin boundaries, e.g. (130), (123), (140) and (114) in Copper, are explored to examine their high energy configurations. In (140) and (114) twin boundaries local atomic adjustments are made to obtain low interfacial energy. The atomic planes coalesce at the twin interface in all the cases. The interactions of vacancy with (130), (123), (140) and (114) boundaries are studied. For single vacancy the maximum binding energy for (123) and (114) boundary is observed when vacancy lies at the plane adjacent to the interface. The structures and energies of (111) (001) and (110) twist boundaries with different misorientation angles in copper, silver, and gold are investigated as well. It is observed that in-plane translations are necessary to establish low energy (110) twist boundary.

Item Type:Thesis (PhD)
Uncontrolled Keywords:atomic simulation, computer simulation, symmetry of clusters, twin boundary, point defect clusters
Subjects:Physical Sciences (f) > Physics(f1)
ID Code:434
Deposited By:Mr. Muhammad Asif
Deposited On:03 Aug 2006
Last Modified:04 Oct 2007 21:00

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