I= COMPUTER SIMULATION OF POINT DEFECT TWIN BOUNDARY INTERACTIONS IN FACE CENTERED CUBIC METALS
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Title of Thesis
COMPUTER SIMULATION OF POINT DEFECT TWIN BOUNDARY INTERACTIONS IN FACE CENTERED CUBIC METALS

Author(s)
Abdul Ghafoor
Institute/University/Department Details
Islamia University/Physics
Session
1993
Subject
Physics
Number of Pages
80
Keywords (Extracted from title, table of contents and abstract of thesis)
atomic simulation, computer simulation, symmetry of clusters, twin boundary, point defect clusters

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.

Download Full Thesis
495.84 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
38.85 KB
2 1 Introduction 1
80.44 KB
  1.1 Crystal Defects 1
  1.2 Atomic Simulation Techniques 2
  1.3 Brief Review Of Previous Work 3
  1.4 The Computer Simulation Technique 6
  1.5 Many-Body Potential 7
  1.6 Twinning By Atomic Shuffling 9
  1.7 Out Line Of The Thesis 10
3 2 Symmetry Of Point Defect Clusters 11
36.8 KB
  2.1 Introduction 11
  2.2 Symmetry Of Clusters 12
  2.3 Relation Between Variants And Symmetry Of A Cluster 13
  2.4 Results And Discussion 14
4 3 Twin Boundaries In F.C.C. Metals 16
56.33 KB
  3.1 Introduction 16
  3.2 (130) Twin BoundarY 17
  3.2.1 Results And Interpretations 18
  3.3 (123) Twin Boundary 18
  3.3.1 Results And Interpretations 19
  3.4 (140) Twin Boundary 19
  3.4.1 Results And Interpretations 20
  3.5 (114) Twin Boundary 20
  3.5.1 Results And Interpretations 20
  3.6 Discussion 21
5 4 Interaction Of Vacancies With Twin Boundaries in F.C.C. Metals 23
44.56 KB
  4.1 Introduction 23
  4.2 Simulation Techniques 24
  4.3 (130) Twin Boundary 25
  4.3.1 Results And Interpretations 25
  4.4 (123) Twin Boundary 26
  4.4.1 Results And Interpretations 26
  4.5 (140) Twin Boundary 27
  4.5.1 Results And Interpretations 27
  4.6 (114) Twin Boundary 27
  4.6.1 Results And Interpretations 28
  4.7 Discussion 28
6 5 Twist Boundaries 30
84.49 KB
  5.1 Introduction 30
  5.2 (111) Twist Boundaries 31
  5.2.1 ∑ 3(111) Boundary 31
  5.2.2 ∑ 7(111) Boundary 32
  5.2.3 ∑ 13(111) Boundary 33
  5.3 (001) Twist Boundaries 34
  5.3.1 ∑ 5(001) Boundary 34
  5.3.2 ∑ 13(001) Boundary 35
  5.3.3 ∑ 17(001) Boundary 36
  5.4 (110) Twist Boundaries 36
  5.4.1 ∑ 3(110) Boundary 37
  5.4.2 ∑ 9(110) Boundary 38
  5.5 Discussion 39
7 6 General Discussion And Conclusions 41
37.45 KB
  6.1 Discussion 41
  6.2 Conclusions 43
  6.3 Suggestions For Future Work 44
8 7 References 44
32.79 KB
9 8 Tables 50
52.2 KB