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Information
4 Credits
Offered Winter
Lecture Only

OSU catalog link

Prerequisites
ENGR 322 or equivalent

Contact
David Cann
541.737.9623
303D Dearborn Hall

Course Description

This course seeks to give graduate students an understanding of the underlying mechanisms of plastic deformation and creep behavior, give them the ability to qualitatively and quantitatively assess the role of dislocations in plastic deformation, and give them the ability to quantitatively predict creep behavior and creep failure in materials.

Topics

  • Defects in crystals, dislocation geometry, Burgers vectors, Burgers circuit, dislocation branching, slip, slip planes, Peierls-Nabarro stress
  • Crystallography of dislocations, slip systems, cross slip, climb, prismatic loops, resolved shear stress, dislocation mechanics: elasticity, force on dislocations
  • Dislocation mechanics: Stress fields, energy of dislocations, Frank’s rule, line tension, forces between dislocations, image forces
  • Partial dislocations for FCC, HCP, BCC, Super dislocations
  • Dislocation interactions: jogs, kinks, jog motion, long jogs, prismatic loops, extended dislocations and jogs, dislocation forces and interactions
  • Dislocation nucleation, multiplication, arrays, low angle boundaries (LABs), tilt boundaries, twist boundaries, general LABs, Frank’s relation
  • Stress fields and strain energy of dislocation arrays, strengthening mechanisms
  • Creep, creep mechanisms
  • Deformation mechanism maps, creep laws
  • Creep life prediction, superplasticity

Learning Outcomes

The student, upon successful completion of this course, will be able to:

  1. Determine the Burgers vector’s, slip planes, and slip directions for perfect dislocations in common metal crystal structures.
  2. Compute the forces between dislocations to predict preferred dislocation motion and preferred dislocation arrangements.
  3. Apply Frank’s rule to determine favorable dislocation reactions.
  4. Correctly identify the results of interactions between perfect dislocations.
  5. Correctly identify the appropriate creep mechanism based on deformation mechanism maps and predict creep lifetimes.