Atomistic aspects of crack propagation along high angle grain boundaries
- Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Materials Science and Engineering
The author presents atomistic simulations of the crack tip configuration near a high angle {Sigma} = 5 [001](210) symmetrical tilt grain boundary in NiAl. The simulations were carried out using molecular statics and embedded atom (EAM) potentials. The cracks are stabilized near a Griffith condition involving the cohesive energy of the grain boundary. The atomistic configurations of the tip region are different in the presence of the high angle grain boundary than in the bulk. Three different configurations of the grain boundary were studied corresponding to different local compositions. It was found that in ordered NiAl, cracks along symmetrical tilt boundaries show a more brittle behavior for Al rich boundaries than for Ni-rich boundaries. Lattice trapping effects in grain boundary fracture were found to be more significant than in the bulk.
- Sponsoring Organization:
- National Science Foundation, Washington, DC (United States); Office of Naval Research, Washington, DC (United States)
- OSTI ID:
- 571802
- Report Number(s):
- CONF-961202--
- Country of Publication:
- United States
- Language:
- English
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