Abstract
Molecular dynamics simulations were performed to study the effect of the composition of the intergranular film (IGF) on grain growth in α-Al 2O 3 and β-Si 3N 4 In each case, the IGF is formed while in contact with two differently oriented crystals. Results show preferential growth along the [11̄20] direction of the (11̄20) surface in comparison to growth along the surface normal on the (0001) surface for certain calcium alumino-silicate compositions in the alumina system. However, in the silicon nitride system, preferential growth occurred along the surface normal on the (0001) surface in comparison to that in the (10̄10) surface. Such preferential growth in each system is consistent with experimentally observed anisotropic grain growth in each of the different systems. Platelets form in the alumina system because of faster outward growth of the prism orientations than the basal orientation, while the more rapid growth along the basal surface normal in the nitride system causes anisotropic growth to manifest itself as whisker growth. In the alumina system, the simulations show the mechanism by which Ca ions in the IGF inhibit growth on the basal surface and the Ca/Al ratio in the IGF plays an important role in the change from isotropic to anisotropic grain growth. At compositions with high or low Ca/Al ratios, growth along each surface normal is equivalent, indicating isotropic grain growth. The simulations provide an atomistic view of attachment onto crystal surfaces, affecting grain growth in alumina.
| Original language | English |
|---|---|
| Title of host publication | Ceramic Transactions |
| Pages | 19-30 |
| Number of pages | 12 |
| Volume | 191 |
| Publication status | Published - 2006 |
| Event | 6th Pacific Rim Conference on Ceramic and Glass Technology, PacRim6 - Maui, HI, United States Duration: Sep 11 2005 → Sep 16 2005 |
Publication series
| Name | Ceramic Transactions |
|---|---|
| Volume | 191 |
| ISSN (Print) | 10421122 |
Other
| Other | 6th Pacific Rim Conference on Ceramic and Glass Technology, PacRim6 |
|---|---|
| Country | United States |
| City | Maui, HI |
| Period | 9/11/05 → 9/16/05 |
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ASJC Scopus subject areas
- Ceramics and Composites
Cite this
Molecular dynamics simulations of the effect of the composition of intergranular films on grain growth. / Garofalini, Steve.
Ceramic Transactions. Vol. 191 2006. p. 19-30 (Ceramic Transactions; Vol. 191).Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
}
TY - GEN
T1 - Molecular dynamics simulations of the effect of the composition of intergranular films on grain growth
AU - Garofalini, Steve
PY - 2006
Y1 - 2006
N2 - Molecular dynamics simulations were performed to study the effect of the composition of the intergranular film (IGF) on grain growth in α-Al 2O 3 and β-Si 3N 4 In each case, the IGF is formed while in contact with two differently oriented crystals. Results show preferential growth along the [11̄20] direction of the (11̄20) surface in comparison to growth along the surface normal on the (0001) surface for certain calcium alumino-silicate compositions in the alumina system. However, in the silicon nitride system, preferential growth occurred along the surface normal on the (0001) surface in comparison to that in the (10̄10) surface. Such preferential growth in each system is consistent with experimentally observed anisotropic grain growth in each of the different systems. Platelets form in the alumina system because of faster outward growth of the prism orientations than the basal orientation, while the more rapid growth along the basal surface normal in the nitride system causes anisotropic growth to manifest itself as whisker growth. In the alumina system, the simulations show the mechanism by which Ca ions in the IGF inhibit growth on the basal surface and the Ca/Al ratio in the IGF plays an important role in the change from isotropic to anisotropic grain growth. At compositions with high or low Ca/Al ratios, growth along each surface normal is equivalent, indicating isotropic grain growth. The simulations provide an atomistic view of attachment onto crystal surfaces, affecting grain growth in alumina.
AB - Molecular dynamics simulations were performed to study the effect of the composition of the intergranular film (IGF) on grain growth in α-Al 2O 3 and β-Si 3N 4 In each case, the IGF is formed while in contact with two differently oriented crystals. Results show preferential growth along the [11̄20] direction of the (11̄20) surface in comparison to growth along the surface normal on the (0001) surface for certain calcium alumino-silicate compositions in the alumina system. However, in the silicon nitride system, preferential growth occurred along the surface normal on the (0001) surface in comparison to that in the (10̄10) surface. Such preferential growth in each system is consistent with experimentally observed anisotropic grain growth in each of the different systems. Platelets form in the alumina system because of faster outward growth of the prism orientations than the basal orientation, while the more rapid growth along the basal surface normal in the nitride system causes anisotropic growth to manifest itself as whisker growth. In the alumina system, the simulations show the mechanism by which Ca ions in the IGF inhibit growth on the basal surface and the Ca/Al ratio in the IGF plays an important role in the change from isotropic to anisotropic grain growth. At compositions with high or low Ca/Al ratios, growth along each surface normal is equivalent, indicating isotropic grain growth. The simulations provide an atomistic view of attachment onto crystal surfaces, affecting grain growth in alumina.
UR - http://www.scopus.com/inward/record.url?scp=33746083603&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33746083603&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:33746083603
SN - 0470083883
SN - 9780470083888
VL - 191
T3 - Ceramic Transactions
SP - 19
EP - 30
BT - Ceramic Transactions
ER -