Dry sliding friction and wear behavior of ramie fiber reinforced epoxy composites

Abstract

The tribo-potential of ramie (Boehmerianivea) fiber reinforced epoxy polymer has not been explored so far. The present work focuses on developing a new tribo-material for brake pad applications by reinforcing epoxy polymer with an Indian variety of ramie fiber (R-1411; Hazarika). As ramie fiber contains gum, degumming, and bleaching processes are, therefore, carried out to remove gum and to improve characteristics of the fiber. Afterward, SEM, XRD, and TGA analysis are carried out to understand surface characteristics, crystallinity changes, and thermal stability for fiber. Composites are developed using different weight fractions of ramie fiber (0%, 10%, 20%, 30% and, 40%) using hand lay-up technique. Reinforcement of ramie fiber is done in woven fabric (bidirectional mat) form. Investigation of frictional and wear behavior of developed composites are evaluated under five different loads at a sliding speed of 1 m s−1 and sliding distance of 1000 m. Moreover, in order to investigate the effect of speed on friction and wear behaviour, testing at 1.5 m s−1 and 2 m s−1 has also been performed. The experimental findings show that reinforcement of ramie fiber into epoxy matrix significantly improves the wear resistance of neat epoxy. Wear resistance at low loads (10 N) improved by 75% and at higher loads (30 N) improved by 66.67%. The COF increased with an increase in fiber loading. The increase in applied load led to increase in wear loss while, in case of COF it increases up to 25 N load and after that it starts decreasing. The increase in sliding speed led to decrease in COF, however, the wear loss increases for neat polymer and decreases for reinforced composites. To evaluate the wear mechanism of fabricated composites, worn surface morphology study is carried out using scanning electron microscopy (SEM).