Concepedia

Processing and Performance of an All‐Oxide Ceramic Composite

Carlos G. Levi, James Y. Yang, B.J. Dalgleish, Frank W. Zok, A.G. Evans

Journal of the American Ceramic Society · 1998 · 250 citations · 34 references

TL;DR

Oxide‑based continuous fiber ceramic composites are sought for high‑temperature use because of their oxidative stability, and an optimal matrix combining toughness and strength can be achieved by incorporating finely distributed porosity. The study discusses microstructural and processing issues that influence these mechanical behaviors. The authors investigated vacuum infiltration of aqueous mullite‑alumina slurries into woven alumina fiber preforms to realize the proposed matrix design. The resulting composites exhibit stress‑strain behavior comparable to other CFCCs, particularly carbon‑matrix variants, and show promising notch resistance and creep performance.

Abstract

Continuous fiber ceramic composites (CFCCs) based on oxides are of interest for high‐temperature applications owing to their inherent oxidative stability. An enabling element is a matrix with an optimum combination of toughness and strength, which may be achieved by incorporating a controlled amount of fine, well‐distributed porosity. Implementation of this concept by vacuum infiltration of aqueous mullite‐alumina slurries into two‐dimensional woven preforms of alumina fibers has been investigated. Evaluation of these materials shows stress‐strain characteristics similar to other CFCCs, especially carbon‐matrix composites. Moreover, promising notch and creep properties have been found. Microstructural and processing issues relevant to the attainment of these behaviors are discussed.