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This paper describes test results from an experimental fibered KEVLAR®, copper-free para-aramid needlefelt composite friction material enhanced with benign metal nanoparticles. Kevlar felt-reinforced polyimide composite, enhanced with nanoparticles, exhibit a higher coefficient of friction than similar friction materials without nanoparticles but retain the low wear rate exhibited by those materials during full scale dynamometer testing, using the J2430 test. The threshold nanoparticle content to produce appreciable friction coefficient gains was determined. At the content levels investigated, the rotor wear was virtually undetectable while low wear rate was comparable with those materials without nanoparticles. Agglomeration and distribution of nanoparticles was investigated as it pertains to friction performance and wear. New environmental regulations limiting copper content in friction materials will restrict the use of popular components found in conventional friction.

The objective of this paper is to announce the results of testing and analysis, including friction characteristics and thermal properties, of a friction material from a novel manufacturing process. A Kevlar felt-reinforced polyimide matrix composite (“Braketex®”), including results with fiber modifications hybridized with glass or carbon nanofibers, is investigated. Dry brake friction testing on a dynamometer simulating various aircraft landing brake energy levels using disc samples having 4.625″ O.D. × 3.625″ I.D. (11.7475cm × 9.2075cm friction area is equal to 41.74 cm2) single friction material surfaces against cast iron and other reactor surfaces was conducted. Thermal conductivity of Braketex was low and reactor plates absorbed most energy, showing insignificant wear below 50% of the energy level simulating a Boeing 747 normal landing. Friction stability was exhibited through approximately 80% of the landing energy.