Mullite phase equilibria in the system: CaO--Al/sub 2/O/sub 3/--SiO/sub 2/

Technical Report · Fri Oct 01 04:00:00 EDT 1976

DOI:https://doi.org/10.2172/7313811· OSTI ID:7313811

Draper, V F

Sapphire-liquid diffusion couples annealed in sealed molybdenum crucibles in the temperature range of 1602/sup 0/C to 1787/sup 0/C were analyzed by electron beam microprobe. Interfacial compositions across the phase boundaries were used to determine the stable composition range of the mullite phase field and the location of the mullite-corundum boundary. Experiments utilizing quenching methods were also conducted to establish the extent that the metastable nature of the Al/sub 2/O/sub 3/-SiO/sub 2/ system extended into the ternary CaO-Al/sub 2/O/sub 3/-SiO/sub 2/ system and to determine any solid solubility of CaO in mullite. Further evidence was obtained to confirm the recognized value of approximately 82.5 wt percent Al/sub 2/O/sub 3/ as the upper solubility limit for metastable disordered mullite in the binary Al/sub 2/O/sub 3/-SiO/sub 2/ system.

• Research Organization: California Univ., Berkeley (USA). Lawrence Berkeley Lab.
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 7313811
• Report Number(s): LBL-5706
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CALCIUM COMPOUNDS
CALCIUM OXIDES
CHALCOGENIDES
DIAGRAMS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MINERALS
MULLITE
OXIDES
OXYGEN COMPOUNDS
PHASE DIAGRAMS
PHASE TRANSFORMATIONS
SILICON COMPOUNDS
SILICON OXIDES
VERY HIGH TEMPERATURE