UHTC: Convection Patterns in Liquid Oxide Films on ZrB2-SiC Composites Oxidized at High Temperature |
|
Collaborators: CNR-ISTEC Italy
|
|
Materials:
Ceramics
Application: Structural Technique: Characterization |
|
Recently, convection patterns in liquid oxide films formed during oxidation of ZrB2-SiC composites at temperature between 1400-1600oC has been discovered by Karlsdottir and Halloran. During the high temperature oxidation of ZrB2-SiC composites, liquid boron oxide is formed at the ZrB2-ZrO2 interface and transported through the overlying layer of silicate liquid by convection, forming distinct convection cells arranged like the petals of a flower. The convection cells are localized by a viscous fingering phenomenon, as the fluid borate liquid rises through the viscous silicate layer. The up-welling borate liquid contains dissolved zirconium dioxide, which deposits in center of the flower-like structure as the boron oxide evaporates. The driving force for borate flow is the volume increase upon oxidation of ZrB2. Convective transport of borate liquids suggests a novel mechanism for the high temperature oxidation of these materials. |
Skip to content.
Skip to navigation
Materials Science and Engineering, University of Michigan
Sections
- UHTC: Convection Patterns in Liquid Oxide Films on ZrB2-SiC Composites Oxidized at High Temperature
| P.I.: | John Halloran |
|---|---|
| Sponsor: | ONR |