Tribo Performance of T-bfrp Composite Subjected to Dry/Wet Contact Conditions - Natural Polymers, Biopolymers, Biomaterials, and Their Composites, Blends, and IPNs - page 310

Wet Contact Condition
From Figure 9(a), when the composite is subjected to low applied load (70 N) and longer
sliding distance (6.72 km), the fibers were squeezed parallel to the sliding force caus-
ing debonding of fibers. The SEM image also concludes that the fibers were torn apart.
However, the fibers were still in good shape that is no delamination. Consequently at
higher applied loads (200 N) and shorter sliding distance (1.68 km); cf. Figure 9(b); the
wear was initiated by debonding of fibers especially the ones close to the resinous re-
gions associated with torn fibers which eventually formed wear debris during the sliding.
The wear debris could have left very fine grooves on the worn surfaces of the composite
as evidenced in Figure 9(b) marked 'Fg'. When the wear escalates to 6.72 km of sliding
distance; Figure 9(c), the predominant wear mechanism is due to debonding and delami-
nation of fiber mats. The Figures also confirm that there were no signs of fine grooves
evidenced on the worn surfaces as the water had washed away the generated wear debris
during longer sliding distance, that is 6.72 km. This may be the main reason why Ws was
significantly lower at higher applied loads; 200 N which is confirmed by Figure 6(b).
Figure 9. Micrographs of T-BFRP composite under 70 N and 200 N at different sliding distances for
wet contact condition (a) 70 N, 6.72 km; (b) 200 N, 1.68 km; (c) 200 N, 6.72 km
(De: debonding, Dl: delamination, Dt: detachment, Fg: fine grooves, Fd: fine debris, Tf: torn fiber)