THE EFFECT OF LAMINATE ORIENTATIONS ON FRICTION AND WEAR MECHANISMS GLASS-REINFORCED POLYESTER COMPOSITE

Friction and wear properties of polyester composite reinforced with la minated glass fibres are experimentally examined in three different or ientations, namely, cross-laminar CL, and inter-laminar (normal, NL an d parallel, PL). The rubbing experiments of the composite specimens ar e carried out against abrasive paper (silicon carbide, P600) under var ious sliding speed and loading conditions. Experimental results show t hat PL orientation gives the highest value of friction coefficients fo llowed by NL and CL. Microscopic investigations of the worn surfaces a re conducted to identify the operating wear mechanism. They reveal tha t the weaving configuration in CL orientation inhibits an easy detachm ent of fibres during the wear process. Therefore, intermediate values of wear resistance between PL and NL orientation are obtained. Further more, entrapped soft components of matrix resin between laminates in C L orientation play an important role in reducing the friction coeffici ent. In NL orientation, the individual fibres within the laminates do not get mutual support as in PL orientation. As a result, fibres suffe r bending at their ends, leading to an easy shear mechanism.