Computerized simulation of grain boundary character in a superplastic aluminum alloy
High-angle grain boundaries are generally deemed necessary for superplasticity in metals. In polycrystalline materials the grain boundary character must be described in terms of a probability distribution rather than by a single parameter, and little has been reported on the relationship between this distribution and fine-grain superplasticity. For aluminum alloys that exhibit continuous recrystallization the results of computer-aided electron backscatter diffraction analysis have shown that bimodal grain boundary disorientation distributions are present in as-processed material and persist during subsequent annealing. Such distributions may be simulated by computer methods based on a model of the microstructure which assumes that deformation banding occurs during deformation processing. High-angle boundaries ({ge} 30{degree}) develop in association with deformation banding while boundaries of lower disorientation (< 30{degree}) develop by dislocation reaction within the bands. Improved understanding of the grain boundary types associated with various microstructural transformation mechanisms will aid the design of processes to produce superplastic microstructures.
- Research Organization:
- Naval Postgraduate School, Monterey, CA (US)
- OSTI ID:
- 20104650
- Resource Relation:
- Conference: 1999 Materials Research Society Fall Meeting, Boston, MA (US), 11/29/1999--12/01/1999; Other Information: PBD: 2000; Related Information: In: Superplasticity -- Current status and future potential. Materials Research Society symposium proceedings, Volume 601, by Berbon, P.B.; Berbon, M.Z.; Sakuma, T.; Langdon, T.G. [eds.], 386 pages.
- Country of Publication:
- United States
- Language:
- English
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