13th International Conference on Fracture June 16-21, 2013, Beijing, China -6- At stresses above σys0.2% the phenomenon of multiple cracking is also evident in the material, showing the complexity of the fracture behaviour of the material. In Figure 6 below this phenomenon can easily be seen in the left picture. The right picture is zoomed out from the left showing obviously multiple cracking. Figure 6. Showing voids inside graphite flakes (i), delamination of the graphite-matrix interface (ii), plastic deformation at graphite tips (iii) and a bulge (iv). Fractorgraphy revealed that both ductile-like and cleavage-like fracture is present in flake cast iron. Near the notch almost all pearlite grains showed evidence of ductile crack surface, whereas the opposite side of the sample showed mainly river-pattern in the cracked pearlite associated with cleavage fracture. In Figure 7 below both these features can be seen along with a part of a graphite flake. Figure 7. Fracture surface showing features associated with both ductile and brittle fracture in the pearlite matrix. On the right side a part of a graphite flake is seen.
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