Project Title:

Innovative Oxidation Protection Systems for Carbon-Carbon Composites

92-1-04.07-1980                                                   NAS01-19920
Innovative Oxidation Protection Systems for
     Carbon-Carbon Composites 
Materials & Electrochemical Research
7960 South Kolb Road
Tucson, AZ  85706
R.O. Loutfy                                          (602-574-1980)

Abstract:

     This project addresses the need for adequate oxidation
protection systems for carbon-carbon (C-C) composites that enable
operation for more than 1000 hours at temperatures up to 1650øC
for the aerospace and turbine engine industries. Superior
oxidation resistance C-C composites may be achieved through
production of Si and Si3N4 surface layers. Current processing
techniques result in thermal expansion mismatch difficulties which
cause microcracking and the subsequent oxidation of the C-C
composite. This problem is generally viewed as the limiting factor
in the use of C-C composites for high temperature, structural
applications in an oxidizing environment. The project's approach
involves the use of an innovative processing technique that will
minimize thermal expansion mismatch difficulties by optimizing the
surface layers while retaining the excellent properties of the C-C
composites. Samples will be fully characterized in terms of
microstructural characteristics, mechanical properties, and
oxidation resistance by both isothermal and cycling tests.

Potential Commercial Application:

Potential Commercial Applications:  Potential applications include
components for airframe applications (e.g., nose caps, thermal
protection systems), friction applications (e.g., aircraft brake
discs), propulsion applications (e.g., rocket nozzle throats) and
military applications (e.g., nose tips). Other potential
applications include medical prostheses, chemical heat exchangers,
and turbine engine rotors.

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