Interface engineering in alumina/glass composites. Final report, 1 Mar 89-29 Feb 92

Technical Report · Sat Feb 29 04:00:00 EST 1992

OSTI ID:5264879

Chawla, K K

The work done in the past three years has demonstrated the feasibility of developing alumina fiber based glass matrix composites for structural applications by applying an interface engineering approach. Composites consisting of a glass matrix containing coated and uncoated continuous alumina type fibers, were produced by slurry impregnation method. A tin dioxide coating was used for the PRD-166 (alumina + zirconia) fiber, while a boron nitride coating was used for the Nextel 480 (alumina + silica + boria) fiber. Coatings were applied by chemical vapor deposition (CVD). Important parameters in the coating process, in order to obtain a uniform coating on the fiber surface, are the deposition temperature and time. Tin dioxide coating forms an effective barrier between alumina and glass, and thereby prevents strong chemical bonding between the components of this composite system. Improvements in mechanical properties can be achieved by incorporation of such fibers into a brittle matrix. The primary mode of toughening in coated PRD-166/glass composites is crack deflection and fiber bridging while in coated Nextel/glass and Saphikon/glass composites, fiber pullout also occurs. A strong potential exists for enhancing toughness even further provided the surface roughness of the interfaces can be controlled. Preliminary tests carried out on smooth single crystal alumina fiber reinforced glass matrix composites have indicated that extensive fiber matrix debonding and pullout can result with SnO2 coating.

• Research Organization: New Mexico Inst. of Mining and Technology, Socorro, NM (United States). Dept. of Metallurgical and Materials Engineering
• OSTI ID: 5264879
• Report Number(s): AD-A-248587/8/XAB; CNN: N00014-89-J-1459
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601* -- Other Materials-- Preparation & Manufacture
360603 -- Materials-- Properties
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BRITTLENESS
CARBIDES
CARBON COMPOUNDS
CHALCOGENIDES
COATINGS
COMPOSITE MATERIALS
FABRICATION
FIBERS
GLASS
INTERFACES
MATERIALS
MATRIX MATERIALS
MECHANICAL PROPERTIES
METALLURGY
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
REINFORCED MATERIALS
SILICON CARBIDES
SILICON COMPOUNDS
STRESSES
THERMAL STRESSES