The proper selection of polymeric fibers reinforcing epoxy based on the tribological properties isexperimentally investigated in the present work. The effect of reinforcing epoxy matrix by continuous polyamide (PA), Kevlar and polyester (PET) fibers on the friction and wear at dry sliding against steel surface is tested.
It was observed that PA reinforcing epoxy matrix displayed the highest friction coefficient and the lowest wear. The favorite behavior of polyamide can be explained on the basis of the triboelectrification of the tested composites during friction with steel surface. It was found that ESC generated from the friction of PET and steel was higher than that generated from steel and epoxy. The nature of PA fibers influenced the sign of ESC built up on steel counterface, where the resultant ESC showed lower values than that observed for PET fibers.
In the presence of Kevlar as reinforcement, ESC showed higher values than that observed for PET due to the rank of the two sliding materials in the triboelectric series.The attractive force between steel and Kevlar is much higher than that expected for steel and epoxy, where the intensity of ESC controls the strength of the attractive force. Adhesion of Kevlar into steel surface was stronger than the adhesion of epoxy into steel. Consequently, friction force increased with increasing adhesion between the two contact surfaces. As the surface area covered by Kevlar increased, friction increased more than that displayed by the surface area covered by epoxy. Proper selection of fibers in epoxy matrix based on their triboelectrification can control polymer transfer into steel surface and influence both friction and wear.