1. YouTube: SEM study of slip in deformed cadmium single crystalSEM study of slip in deformed cadmium single crystal Reduced Strength due to Dislocations: YouTube: Model of slip by the movement of an edge dislocation Dislocation processes in precipitation-hardened metals during in situ deformation in an HVEMModel of slip by the movement of an edge dislocation Dislocation processes in precipitation-hardened metals during in situ deformation in an HVEM YouTube: 3D atom dislocation3D atom dislocation Predicted by Theory: YouTube: Slip by movement of whole lattice planesSlip by movement of whole lattice planes YouTube: Aluminum Tensile Test.Aluminum Tensile Test. YouTube: Dislocation motion along grain boundary.avi YouTube: Dislocations in motionDislocation motion along grain boundary.aviDislocations in motion Save until defects: YouTube: “Brass Tension Test”“Brass Tension Test”

2. Materials Moments: Tareq/Hisham—Creating new polymer composites Ryan/Jesse—Footballs

3. Uniform vs. Non-uniform plastic deformation

4. fig_06_11 Engineering Stress-strain curve for typical metals

5. YouTube YouTube: Aluminum Tensile Test.Aluminum Tensile Test. Stress-strain curve shown

6. Question of the Day: How does Ductility relate to Plastic Deformation?

7. Ductility % plastic strain at fracture (after subtracting off elastic recovery)

8. Toughness http://www.sciencedirect.com/science/article/pii/S014296120700988X The effect of aging on crack-growth resistance and toughening mechanisms in human dentin

9. Hardness Resistance to scratching, denting http://www.hardnesstesters.com/Products/Accessories/Indenters.aspx

10. Brittle Deformation http://jbo.wikipedia.org/wiki/File:Broken_glass.jpg

11. Brittle Deformation Brittle—Little or no plastic deformation before failure http://www.gowelding.com/met/pwht.htm New Steel Pressure Vessel Failed during Hydraulic Test Improper heat Treatment after Welding (PWHT)

12. Brittle Materials Very little plastic deformation before failure Fracture strains <5%

13. Brittle Deformation Cast Aluminum Motorcycle Engine Cover

14. Cast Iron Cast Aluminum Ultra High-C Steel Brittle Metals

15. Brittle Materials mild steel: 0.16–0.29 wt% C Cast Iron: 3.0-4.5 wt% C (ductile) (brittle)

16. Brittle Failure: Tensile test of Nodular Graphite Cast Iron

17. Engineering Stress-Strain for metals

19. Deformation on the atomic scale Elastic Plastic Brittle

20. Mechanical Property terms Elastic - Elasticity Plastic - Plasticity Stiff - Stiffness Ductile - Ductility Strong - Strength Brittle - Brittleness Tough - Toughness Hard - Hardness

21. Chapter 7 Section 7.1–7.4 Dislocations Slip Systems

22. Plastic deformation is due to atomic-level Shear stresses

23. How do we generate shear stresses when a sample is in a tensile test? Plastic Deformation

24. f07_07_pg182 Max. shear stress is on a plane 45º from the tensile stress

25. f08_07_pg182 Fig. 7.8 Single xl after plastic deformation due to tensile stress Before deformation

26. Shear Stress required for plastic deformation in single Cu crystal (Based on atomic bonding strengths)  theoretical ≈ 1000 Mpa  true < 100 MPa (  = shear stress)

27. Predicted by Theory: YouTube: Slip by movement of whole lattice planes Slip by movement of whole lattice planes

28. Line defects edge dislocation, screw dislocation

29. YouTube: “Brass Tension Test”“Brass Tension Test” Plastic Deformation YouTube: 3D atom dislocation3D atom dislocation YouTube: Model of slip by the movement of an edge dislocationModel of slip by the movement of an edge dislocation

30. Real Dislocations: Dislocation processes in precipitation-hardened metals during in situ deformation in an HVEM YouTube: Dislocation motion along grain boundary.avi YouTube: Dislocations in motion YouTube: Copy of particle disl inter high t.avi Dislocation processes in precipitation-hardened metals during in situ deformation in an HVEMDislocation motion along grain boundary.aviDislocations in motion Copy of particle disl inter high t.avi

31. SEM {100} planes SEM single crystal of cadmium deforming by dislocation slip on {100} planes.

32. f09_07_pg183 Fig. 7.9 Slip in a single zinc crystal YouTube: SEM study of slip in deformed cadmium single crystalSEM study of slip in deformed cadmium single crystal

33. Slip Systems: { x y z }

34. Fig. 7.6 Slip Systems

35. Table 7.1

36. (1 0 1 0) (1 1 0 0) (0 1 1 0) (1 0 1 0) (1 1 0 0) (0 1 1 0)

37. Plastic Deformation Section 7.5: Single Crystals

38. f07_07_pg182 Max. shear stress is on a plane 45º from the tensile stress

39. f08_07_pg182 Slip in a single crystal Fig. 7.8

40. Table 7.1

41. Dislocation Densities Range: 10 3 mm -2 10 10 mm -2 Carefully solidified Metals Highly deformed Metals

42. When it comes to Plastic Deformation… Dislocations Rule!

43. Plastic Deformation Section 7.6: Polycrystalline Materials

44. f10_07_pg186 Plastic Deformation: Slip in Polycrystalline Copper Fig. 7.1 (173x photomicrograph)

45. f11_07_pg186 Plastic Deformation: Polycrystalline Cold-worked Nickel Before deformationAfter deformation Fig. 7.11--170x photomicrograph