A grain-boundary diffusion model of dynamic grain growth during superplastic deformation

Journal Article · Wed Sep 29 04:00:00 EDT 1999 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(99)00201-3· OSTI ID:20000485

Kim, Byung-Nam; Hiraga, Keijiro; Sakka, Yoshio; Ahn, Byung-Wook

Dynamic grain growth during superplastic deformation is modelled on the basis of a grain-boundary diffusion mechanism. On the grain boundary where a static and a dynamic potential difference coexist, matter transport along the boundary is assumed to contribute to dynamic grain growth through depositing the matter on the grain surface located opposite to the direction of grain-boundary migration. The amount of the diffusive matter during deformation is calculated for an aggregate of spherical grains and is converted to the increment of mean boundary migration velocity. The obtained relationship between the strain rate and the dynamic grain growth rate is shown to be independent of deformation mechanisms, provided that the grain growth is controlled by grain-boundary diffusion. The strain dependence, strain-rate dependence and temperature dependence of grain growth predicted from this model are consistent with those observed in superplastic ZrO{sub 2}-dispersed Al{sub 2}O{sub 3}.

• Research Organization: National Research Inst. for Metals, Tsukuba, Ibaraki (JP)
• OSTI ID: 20000485
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 12 Vol. 47; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
DEFORMATION
DIFFUSION
GRAIN BOUNDARIES
GRAIN GROWTH
MATHEMATICAL MODELS
STRAIN RATE
TEMPERATURE DEPENDENCE
ZIRCONIUM OXIDES