The Potential of Using Betelnut Fibres for Tribo-Polyester Composites Considering Three Different Orientations

This paper presents an attempt to use betelnut fibres as reinforcement for tribo-polyester composites in bearing applications. The composite was fabricated using the hand lay-up technique, and contains 15 layers of randomly distributed chopped fibres and 17 layers of polyester. The adhesive wear and frictional behavior of the composites were studied against a polished stainless steel counterface using block-on-disc (BOD) machine at different applied loads (5–30N) and sliding distance (0–7km). In addition to that, the orientation of the fibre layers with respect to the sliding direction of the counterface was considered, i.e. parallel (P-O), anti-parallel (AP-O) and normal (N-O). Studies on worn surfaces, using a scanning electron microscope (SEM), and roughness profiles of the composite and counterface assisted to explain the results. As a result of this work, it was found that applied load has less effect on the specific wear rate and friction coefficient of the composite especially in P-O and AP-O. Meanwhile, in both orientations (P-O and AP-O), the steady state of specific wear rate was reached after 5 km sliding distance. On the other hand, the composite behaved differently in N-O, where the wear and friction increased when the load and sliding distance increased. This was due to the poor support of the fibres in that orientation, where delamination, pull out and breakage in the fibres were observed. In P-O and AP-O, the wear mechanism was predominated by plastic deformation and micro-cracks.