Project Title:

A Transformation Zr02 Whisker Reinforced Alumina Composite

04.01-3257A
A Transformation Zr02 Whisker Reinforced Alumina Composite
Materials & Electrochemical Research Corporation
4600 N. Via Madre
Tucson
AZ
85749
Withers
J. C.
24872
50,000
LeRC

Abstract:

There is a great demand in space, defense and commercial applications for an oxidation
resistant, lightweight, high modulus and high strength ceramic composite with exceptionally
high static and dynamic toughness.  Phase transformation toughening such as with
Zr02 and absorption for microcracking at boundary surfaces such as at whisker-matrix
interface are known toughening-strengthening mechanisms.  The full potential or these
toughening mechanisms have not been achieved by the traditional route of combining
powders and consolidating.  Combining sol gel technology with the addition of whiskers
can result in a fine grained alumina matrix composite with whiskers and fine grained
Zr02 at the alumina grain boundaries to produce a composite with substantially improved
toughness and strength, and oxidation resistance to about 1500oC.  This project utilizes
unique sol gel technology and a statistical designed experimental regime to produce
an alumina matrix composite strengthened and toughened with Zr02 and whiskers which
will have diverse uses in space and defense mission applications and commercially
in cutting tools and heat engines.