High Temperature Colloidal Processing for Glass-Metal FGM's
| Autor: | L. Esposito, E. Saiz, A. P. Tomsia, R. M. Cannon |
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| Jazyk: | angličtina |
| Rok vydání: | 1998 |
| Zdroj: | International Materials Symposium on ceramic microstructures '96, pp. 503–512, Berkeley, California, June 24-27, 1996 info:cnr-pdr/source/autori:L. Esposito, E. Saiz, A. P. Tomsia and R. M. Cannon/congresso_nome:International Materials Symposium on ceramic microstructures '96/congresso_luogo:Berkeley, California/congresso_data:June 24-27, 1996/anno:1998/pagina_da:503/pagina_a:512/intervallo_pagine:503–512 |
| Popis: | The paper proposes a basis for understanding the microstructural evolution of functionally graded materials (FGM's) which can provide guidance for tailoring various fabrication processes. Fabrication methods that have been used often rely on a liquid phase being present. However, preliminary experiments and analysis reveal that these specific methods can be considered as subsets of a more general situation that depends upon the colloidal behavior of a solid phase in a liquid. Once this is realized, numerous hybrid methods can be conceived to better fabricate materials including graded ones. The critical behavior that will occur depends upon the extent to which the liquid wets the solid surfaces as well as the solid-solid interfaces, i.e., grain boundaries. The applicable fabrication methods plus the resulting degrees of interconnectivity of the two phases will, thus, depend on specific combinations of these controlling parameters. The present paper describes a framework in which criteria for forming FGM's are given based upon these considerations: 1) wetting of the solid by the liquid; 2) penetration of grain boundaries of the solid by the liquid; and 3) flocculation or not of the solid particles in the liquid. These issues must be augmented by: 4) dominant sintering mechanism and sintering rate of a network of solid particles immersed in liquid; and 5) materials compatibility. Various classes of behavior are illustrated based upon interactions of high temperature glasses (mainly within the system Al2O3-Y2O3-SiO2) and metals or ceramics. |
| Databáze: | OpenAIRE |
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