The use of solid-state reactions with volume loss to engineer stress and porosity into the fiber-matrix interface of a ceramic composite

Journal Article · Fri Sep 01 04:00:00 EDT 1995 · Acta Metallurgica et Materialia

DOI:https://doi.org/10.1016/0956-7151(95)00033-R· OSTI ID:105981

Hay, R S ^[1]

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1. Wright Lab., Wright-Patterson AFB, Dayton, OH (United States). Materials Directorate

The effect of the 11 vol% losing during reaction of yttrium-aluminas garnet (YAG) and zirconia was observed in zirconia coated single-crystal alumina fiber-YAG matrix composites. The reaction caused plastic deformation in the alumina fibers, and possibly a minor amount of porosity at fiber-matrix interfaces that was usually indistinguishable from matrix porosity. The results were analyzed by models for diffusive cavitation modified to use reaction self-stress. Crack-healing, tensile stress states along the reaction front that approach plane stress, and the small volume of self-stressed material make crack-like pores unlikely at the high temperatures required for reaction. Smaller matrix grains might promote formation of smaller cavities but are also incompatible with high temperature. Both modeling and experiment suggest that sufficient porosity for crack deflection and fiber pullout cannot form unless processing methods that form dense composites at lower temperatures are used.

• OSTI ID: 105981
• Journal Information: Acta Metallurgica et Materialia, Journal Name: Acta Metallurgica et Materialia Journal Issue: 9 Vol. 43; ISSN 0956-7151; ISSN AMATEB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
ALUMINIUM OXIDES
CHEMICAL REACTIONS
COMPOSITE MATERIALS
CRACKS
CRYSTAL STRUCTURE
INTERFACES
MATHEMATICAL MODELS
MONOCRYSTALS
PLASTICITY
POROSITY
RESIDUAL STRESSES
YTTRIUM OXIDES
ZIRCONIUM OXIDES