Effect of crystallization of grain boundary phase on the high temperature strength of silicon nitride ceramics. Final report, April 1, 1980-March 31, 1984. [Sialon-YAG; Sialon-cordierite]

Technical Report · Sun Jan 01 00:00:00 EST 1984

OSTI ID:6916733

Tien, T Y

Grain growth kinetics of SIALON grains during hot pressing were studied. Microchemical analysis work has also been carried out. The decrease of K/sub IC/ value with and increasing amount of YAG in the annealed specimens in the system SIALON-YAG can be attributed to the higher thermal expansion coefficient of the YAG than that of the SIALON crystals. The YAG crystals at the grain boundaries which crystallized at high temperatures during annealing contracted more than the SIALON grains during cooling and tension were generated at the interfaces. Cordierite has a lower thermal expansion coefficient than that of the SIALON crystals. The system SIALON-cordierite was then studied. It was found that the toughness of the ceramics in the system SIALON-cordierite increased upon annealing treatments. Bulk glasses in the system SIALON-cordierite were also prepared. The glass formation and crystallization behavior in this system were studied. The results of the above studies are reported in the following sections: the microchemical analysis of the grain and grain boundary phases in the system SIALON-YAG; grain growth kinetics of ..beta.. grains in the system SIALON-YAG; high temperature mechanical property measurements; the system SIALON-cordierite; and glass formation in the system SIALON-cordierite.

• Research Organization: Michigan Univ., Ann Arbor (USA). Dept. of Materials and Metallurgical Engineering
• DOE Contract Number: AC02-80ER10619
• OSTI ID: 6916733
• Report Number(s): DOE/ER/10619-T1; ON: DE84011786
• Resource Relation: Other Information: Portions are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINATES
MICROSTRUCTURE
ALUMINIUM OXIDES
GARNETS
GLASS
SILICATE MINERALS
SILICON NITRIDES
YTTRIUM COMPOUNDS
ELECTRON MICROSCOPY
GRAIN GROWTH
GRAIN SIZE
KINETICS
PHASE STUDIES
ALUMINIUM COMPOUNDS
CHALCOGENIDES
CRYSTAL STRUCTURE
MICROSCOPY
MINERALS
NITRIDES
NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PNICTIDES
SILICATES
SILICON COMPOUNDS
SIZE
TRANSITION ELEMENT COMPOUNDS
360202* - Ceramics
Cermets
& Refractories- Structure & Phase Studies