Preparation and Characterization of Mullite Fiber Reinforced Alumina Matrix.

Abstract:
In the present study we succeeded in the preparation of short ceramic fiber
reinforced alumina matrix composites which posses properties not tailored
by alumina matrix. The composites were fabricated by mechanical mixing
of 0, 5, 10, 15, and 20 wt% home – made mullite fibers having different
aspect ratios with 95, 90, 85 and 80 wt%alumina matrix powder.
The specimens were sintered at temperatures between 1500°C and 1650°C.
The ceramic matrix composites were characterized b y determining their
physical properties in terms of bulk density and apparent porosity as well
as, their phase composition using X-ray diffraction analysis. SEM
examination and mechanical measurement preformed on only high density
samples from each size fraction and fiber content. It was found that the
properties of the prepared composites depended on the fiber content, the
fiber/matrix interface and the fiber diameter. XRD analysis of the
composites indicates that the fibers did not suffer degradation even when
they were fired at elevated temperatures.
The study showed that it is possible to control the properties of the short
oxide fiber reinforced – alumina matrix composite by controlling the
content and diameter of the oxide fibers. Under such condition s it is easy to
tailor the properties to a specific application.