ME 250 Exam 1

  1. Corrosion
    Involves loss of metal atoms at an anode
  2. Cathode
    Where consumption of the resulting electrons occurs
  3. Galvinized Steel
    Zinc coating protects against corrosion
  4. Chromium
    protects against corrosion
  5. Fe-Cr alloys
    have low ductility and toughness
  6. Stress
    load per unit area
  7. Ultimate Tensile Stress
    the maximum in the stress-strain curve thus it is the load-vearing capacity of a specimen in tension.
  8. Necking
    A region in the specimen begins to thin down more than any other region
  9. Stress and Strain
    size-dependent measures of load and displacement, respectively
  10. elastic behavior
    this reversible behavior often shows a linear relation between stress and strain.
  11. Plastic behavior
    the permanent deformation behavior occurs when the tensile (or compressive) uniaxial stress reaches sigma_y
  12. Microstructure
    the arrangement of phases and grains
  13. Crystallographic points, directions, and planes
    specified in terms of indexing schemes
  14. Slip
    Mechanism of plastic deformation. Motion of planes of atoms in specific planes and directions
  15. Dislocations
    Linear defects in a material; 3 kinds: edge, screw, mixed. Slip occus by the motion of (this).
  16. Plasticity
    Governed by the ease/difficulty of motion of dislocations. Dislocations interact with different objects (other dislocations, solute atoms, grain boundaries, etc) and affect the overall plasticity.
  17. Strain hardening
    Multiplication of dislocations for increased interactions and impediment to dislocation motion. Leads to increased yield strength, increased tensile strength, decreased ductility.
  18. Dislocation density
    increases as a material is plastically deformed
  19. Shear Strain
  20. Yield Stress
    the value at which a material starts to deform plastically.
  21. Cavities
    voids due to increased stress in all directions
  22. Ductility
    A measure of the ability of a material to be defomed plastically without breaking. Inversely related to strength.
  23. Galvanic Series
    Ranks the reactivity of metals/alloys in seawater
  24. Passivation
    the rapid formation of a thin oxide layer by the chemical combination of oxygen atoms with surface atoms of the metal
  25. Unit Cell
    The basic unit of a crystal structure. Structures in three dimensions.
  26. Coordination Number
    In a unit cell, the number of closest neighbors to the central atom.
Card Set
ME 250 Exam 1
Study cards for Material Science