Influence of fiber orientation on abrasive wear of unidirectionally reinforced carbon fiber-polyetherimide composites

A composite with continuous carbon fibers (CF) (80% by vol.) and high performance thermoplastic polyetherimide (PEI) matrix was developed and evaluated for various mechanical properties as a function of fiber orientation angle (0 degrees, 30 degrees, 45 degrees, 60 degrees and 90 degrees). It was observed that Young's modulus, Poisson's ratio, toughness and % strain decreased with the increase of fiber orientation angle with respect to loading direction. In-plane shear modulus was highest for fibers with 45 degrees. Overall, unidirectional (UD) CF reinforcement enhanced all strength properties of PEI significantly. Composites with fibers in 0 degrees (parallel to loading direction) proved best in almost all the properties. Tribological evaluation in abrasive wear mode under different loads and fiber orientations indicated that coefficient of friction (mu) and specific wear rate (K(0)) decreased with load, in general. Comparatively low specific wear rate (K(0)), (in the order of 0.71 x 10(-9) m(3)/Nm) was observed for 0 degrees fiber orientation, while fibers in 90 degrees showed almost three times higher wear rate. Overall fiber reinforcement in 0 degrees orientations proved beneficial from both strength and tribological performance point of view. SEM proved useful to correlate wear rate with surface topography. (C) 2009 Elsevier Ltd. All rights reserved.