Fracture

1. Fracture: Microstructural Aspects
Assignment
Material Science and Enginering

2. Different Fracture Modes

3. Materials with Different Degrees of Brittleness

4. Ductile Fracture
(a) Failure by shear (glide) in a pure metal. (Reprinted with permission from D. Broek, Elementary Engineering Fracture
Mechanics, 3rd ed. (The Hague, Netherlands: Martinus Nijhoff, 1982), p. 33.) (b) A point fracture in a soft single-crystal
sample of copper. (Courtesy of J. D. Embury.)

5. Zener-Stroh Crack

6. Crack Nucleation in HCP Metals
a. Lattice rotation due to bend planes,
b. Lattice rotation due to twinning,
c. Crack nucleation in Zn due to lattice
rotation caused by bend planes. (Courtesy
of J.J. Gilman.)

7. Microcrack Formation at Twins
Initiation of failure by microcrack formation in tungsten deformed at approximately 104
s−1
at room temperature. (a)
Twin steps. (b) Twin steps and twin–twin intersection. (From T. Dümmer, J. C. LaSalvia, M. A. Meyers, and G.
Ravichandran, Acta Mater., 46 (1998) 959.)

8. W-Type Cavitation
w-type cavitation at a grain-boundary triple point.

9. r-Type Cavitation
r-type cavitation at a grain boundary

10. Nucleation of a Cavity at a Second-Phase
Particle
Nucleation of a cavity at a second-phase particle in a ductile material. (Adapted with
permission from B. R. Lawn and T. R. Wilshaw, Fracture of Brittle Solids
(Cambridge: Cambridge University Press, 1975), p. 40.)

11. Dimple Fracture
Dimple fracture resulting from the nucleation, growth, and coalescence of microcavities. SEM. Note the
inclusion, which served as the microcavity nucleation site.

12. Cup and Cone Fracture

13. Cup and Cone Fracture

14. Ductile Fracture by Void Nucleation, Growth, and Coalescence

15. Ductile Fracture Progression: TEM In-situ Results

16. Ductility vs. Volume Fraction of Second Phase
Ductility vs. volume fraction of second phase, f, for copper containing various second phase particles. The dashed line represents
the prediction from the law of mixtures, assuming zero ductility for the second-phase particles. (From B. I. Edelson and W. J.
Baldwin, Jr., Trans. ASM, 55 (1962) 230.)

17. Initiation of Void Growth by Dislocation Emission
Prismatic Loops Shear Loops

18. Ductile-Brittle Transition
Ductile–brittle transition in steel and the effect of loading rate.

19. Propagation of Transgranular Cleavage
Propagation of transgranular cleavage. (Adapted from J. R. Low, in Madrid Colloquium on
Deformation and Flow of Solids (Berlin: Springer-Verlag, 1956), p. 60.)

20. Cleavage Facets

21. Formation of Cleavage Steps

22. Intergranular Fracture

23. Intergranular Fracture in Steel

24. Sources of Flaws in Ceramics

25. Brittle Failure by Axial Splitting
Compressive failure of a brittle material by axial splitting.