Presentation on theme: "2/15/2002, Friday Strengthening Mechanisms. Strengthening Philosophy Plastic deformation is due to the motion of a large number of dislocations; Strength."— Presentation transcript:
2/15/2002, Friday Strengthening Mechanisms
Strengthening Philosophy Plastic deformation is due to the motion of a large number of dislocations; Strength (resistance to deformation) can be improved by putting obstacles to slip
Polycrystalline metals vs. single crystals, which one is stronger?
Dislocation in polycrystalline
Strengthening by grain size reduction The finer the grains, the larger the area of grain boundaries that impedes dislocation motion.
Strain-hardening Ductile metals become stronger when they are deformed plastically.
Dislocation stress fields
Dislocation - dislocation interaction
Chinese ancient sword Chinese Han Dynasty, Bronze Sword, 206BC