1. 2/15/2002, Friday Strengthening Mechanisms

2. 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

3. Polycrystalline metals vs. single crystals, which one is stronger?

4. Dislocation in polycrystalline

5. Strengthening by grain size reduction The finer the grains, the larger the area of grain boundaries that impedes dislocation motion.

6. Grain growth

7. Strain-hardening Ductile metals become stronger when they are deformed plastically.

8. Dislocation stress fields

9. Dislocation - dislocation interaction

10. Chinese ancient sword Chinese Han Dynasty, Bronze Sword, 206BC

11. Japanese ancient sword Samurai

12. Solid Solution Strengthening

13. Precipitation Hardening