TY - JOUR
T1 - Fatigue fracture at copper bicrystal interfaces
T2 - Fractography
AU - Peralta, P.
AU - Laird, C.
AU - Mitchell, T. E.
N1 - Funding Information:
This work was supported by The Department of Energy under Grant No. DE-FG02-84ER-45188, by the Laboratory for Research on the Structure of Matter in the University of Pennsylvania, which provided assistance with central facilities and by a Director-Funded Postdoctoral Fellowship to P. Peralta at Los Alamos National Laboratory. This support is greatly appreciated. We also acknowledge Professor J.L. Bassani, Professor D.P. Pope, and Professor P. Ponte-Castañeda at the University of Pennsylvania and Professor S. Suresh at MIT for valuable comments and discussion.
PY - 1999/5/31
Y1 - 1999/5/31
N2 - The fracture surfaces of intergranular cracks in copper bicrystals with different misorientations, subjected to different mechanical pretreatments and cracking directions, were studied by scanning electron microscopy (SEM). The dislocation structures present before the crack formed and propagated were characterized by transmission electron microscopy (TEM). It was found that they could be either loop patches and persistent slip bands (PSB's) (single slip) or maze and cell structures (multiple slip) depending on the misorientation and the pretreatment. The results showed that these structures influenced the shape of the crack front, which could be aligned close to specific crystallographic directions or straight depending on the prior structure. The crack propagation direction also influenced the morphology of the crack front, macroscopically and microscopically, due to differences in the multiplicity of slip. These results suggest that, for a ductile metal, the fatigue cracking behavior depends mostly on hardening and overall dislocation structure, even when the crack is propagating intergranularly.
AB - The fracture surfaces of intergranular cracks in copper bicrystals with different misorientations, subjected to different mechanical pretreatments and cracking directions, were studied by scanning electron microscopy (SEM). The dislocation structures present before the crack formed and propagated were characterized by transmission electron microscopy (TEM). It was found that they could be either loop patches and persistent slip bands (PSB's) (single slip) or maze and cell structures (multiple slip) depending on the misorientation and the pretreatment. The results showed that these structures influenced the shape of the crack front, which could be aligned close to specific crystallographic directions or straight depending on the prior structure. The crack propagation direction also influenced the morphology of the crack front, macroscopically and microscopically, due to differences in the multiplicity of slip. These results suggest that, for a ductile metal, the fatigue cracking behavior depends mostly on hardening and overall dislocation structure, even when the crack is propagating intergranularly.
KW - Copper bicrystal interface
KW - Fatigue fracture
KW - Fractography
KW - Slip geometry
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U2 - 10.1016/s0921-5093(98)01088-0
DO - 10.1016/s0921-5093(98)01088-0
M3 - Article
AN - SCOPUS:0040313467
SN - 0921-5093
VL - 264
SP - 215
EP - 231
JO - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
JF - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
IS - 1-2
ER -