Friction Performance and Wear of Nanoparticle Enhanced Copper-Free Para-aramid Fibered Needlepunched Composite Friction Material

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.