Anisotropic Dissolution of α-Alumina (0001) and (1120) Surfaces into Adjoining Silicates

Glenn K. Lockwood, Shenghong Zhang, Steve Garofalini

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

The dissolutions of the (0001) and (1120) orientations of α-Al 2O3 into calcium silicate, aluminosilicate, and calcium aluminosilicate melts were modeled using molecular dynamics simulations. In all cases, it was found that the (1120) surface of the crystal destabilizes and melts at a lower temperature than does the (0001) surface. This anisotropy in dissolution counters the anisotropy in grain growth, in which the outward growth of the (1120) surface occurs more rapidly than that on the (0001) surface, causing platelets. However, anisotropic dissolution occurred only at a certain temperature range, above which dissolution behavior was isotropic. The presence of calcium in the contacting silicate melt plays an important role in this anisotropic dissolution, similar to its role in anisotropic grain growth observed previously. However, anisotropic dissolution also occurs in the silicate melts not containing calcium, indicating the importance of the different surface energies. In combination with previous simulations of anisotropic grain growth in alumina, these simulations reveal a complex kinetic competition between preferential adsorption and growth versus preferential dissolution of the (1120) orientation in comparison with the (0001) orientation as a function of temperature and local composition. This, in turn, indicates potential processing variations in which to design morphology in alumina.

Original languageEnglish
Pages (from-to)3536-3541
Number of pages6
JournalJournal of the American Ceramic Society
Volume91
Issue number11
DOIs
Publication statusPublished - Nov 2008

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Silicates
Aluminum Oxide
Dissolution
Alumina
Grain growth
Calcium
Aluminosilicates
Anisotropy
Calcium silicate
Platelets
Interfacial energy
Temperature
Molecular dynamics
Adsorption
Crystals
Kinetics
Computer simulation
Processing
Chemical analysis

ASJC Scopus subject areas

  • Ceramics and Composites
  • Materials Chemistry

Cite this

Anisotropic Dissolution of α-Alumina (0001) and (1120) Surfaces into Adjoining Silicates. / Lockwood, Glenn K.; Zhang, Shenghong; Garofalini, Steve.

In: Journal of the American Ceramic Society, Vol. 91, No. 11, 11.2008, p. 3536-3541.

Research output: Contribution to journalArticle

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