Kinetics of the crack-tip-governed brittle to ductile transitions in intrinsically brittle solids
- Massachusetts Inst. of Tech., Cambridge, MA (United States)
- California Inst. of Tech., Pasadena, CA (United States)
Brittle-to-ductile transitions in the fracture of intrinsically brittle solids manifest themselves in two fundamentally different forms. In the first type of solids exemplified by the BCC transition metals and some alkali halides in which dislocation mobility against the lattice resistance is governed by double kink nucleation, the corresponding fracture transition appears to be controlled by formation of dislocation embryos at crack tips. In the second type of solids exemplified by Si, and possibly all other compounds, dislocation mobility is governed not only by double kink nucleation but by kink mobility as well. In these solids the B-D transitions are known to be controlled by dislocation mobility. Here the authors report first on recent simulations of dislocation embryo formation from Mode I cracks in {alpha} {minus} Fe as generic cases of BCC transition metals, and then on a new model of the mobility controlled transitions, typically in Si. Both models find good experimental confirmation.
- OSTI ID:
- 293117
- Report Number(s):
- CONF-970980--; ISBN 0-87339-381-3
- Country of Publication:
- United States
- Language:
- English
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