Professor James Economy's Group

Development of Novel Polymer, Ceramic and Metal Matrix Composites

[Carbon/BN Composite] [AlB2 Composite] [Polymer Composites]

Carbon/BN Composite

We have developed a new composite based on carbon fibers in a boron nitride matrix, which shows a 10x improvement in wear for aircraft brakes as compared to the currently used carbon/carbon composites. This work has led to a Phase 2 SBIR awarded to EKOS Material Inc., a company with which Economy has close ties.

AlB2 Reinforced Metal Matrix Composites

Aluminum diboride flakes were first investigated as a composite reinforcement for epoxy matrix composites in the 1960's but had the drawbacks of high cost and a high incidence of defects associated with crystalline impurities.  Recently our group has made advances in the in situ processing of the flakes in aluminum that eliminates the presence of impurities as well as reducing the cost of the composite.  A new, low cost method for producing an Al-B alloy with high aspect ratio flakes has been developed using Al, borax, and boric oxide as starting materials.  Higher concentrations of flakes can be obtained by a filtration process that was developed by modified by earlier workers to produce up to 35 v% AlB2 flakes in Al.

Polymer Matrix Composites

Over the past decade our group has developed a family of cross-linked aromatic co-polyesters with acetoxy and carboxylic acid end groups.  As a part of this work, thick section carbon fiber reinforced composites were fabricated using solid-state bonding that occurs through ester interchange.  These co-polyesters also have excellent adhesive properties and good thermal properties.  The current research is focused on developing new cross-linked aromatic polyesters as matrix materials for carbon fiber reinforced composites.  The goal of the program is to produce polymer matrix composites possessing superior properties at elevated temperatures for use in aerospace applications.