Melting and Crystallization of Silicate Systems Relevant to Thermal Barrier Coating Damage

Abstract

The melting and crystallization behaviors of model calcium–magnesium–alumino‐silicate (CMAS) compositions relevant to the degradation of thermal barrier coatings (TBCs) were investigated. A primary goal was to establish a baseline for studies on CMAS reactions with TBC materials, reported separately, and their potential to mitigate degradation. Ternary calcium alumino‐silicate (CAS) compositions investigated melt below their equilibrium solidus owing to their metastable phase constitution. Additions of MgO or FeOx have significant effects on the melting behavior, depending on the C:A:S proportions. Amorphization on cooling is commonplace, with MgO, AlO1.5, and especially FeOx promoting crystallization. The behaviors of amorphous and crystalline versions of the same CMAS are different and depend on heating/cooling rates, with attendant implications for their interaction with TBCs.

Document Details

Document Type
Pub Defense Publication
Publication Date
Jan 28, 2015
Source ID
10.1111/jace.13478

Entities

People

  • Carlos G. Levi
  • Charlotte Ensslen
  • Elisa M. Zaleski

Organizations

  • Office of Naval Research
  • University of California, Santa Barbara
  • University of Stuttgart

Tags

Fields of Study

  • Materials science

Readers

  • Combustion science or combustion engineering.
  • Materials Science and Engineering.
  • Ocean-Atmosphere Mesoscale Modeling, Data Assimilation, and Flux Boundary Layers