Evaluation of glass fiber reinforced polyester composite for multi-pass abrasive wear applications

Multi-pass two-body abrasive (m-2BA) wear behaviour of chopped strand mat (CSM) 450-R-glass fiber reinforced polyester (CGRP) composite material was investigated. In the present study, pin-on-ring configuration with SiC abrasive paper was used under dry contact condition. The effects of three grades of SiC abrasive paper (1500, 1000, and 400) and the orientations (antiparallel, AP; parallel, P; normal, N) of the CSM on the m-2BA wear behaviour were investigated. The m-2BA wear rates of the CGRP composite were measured as a function of different applied normal loads (5-25 N corresponding to 0.037-0.19 MPa) at rotational speed of 100 and 50 rpm for different CSM orientations and different grit sizes of abrasive grains. Experimental results showed that m-2BA wear rate of the CGRP composite increases substantially with increasing the size of the abrasive grits and rotational speed, whereas it tends to decrease with increasing the applied normal load. A 20-70% decrease in the wear rate at higher load was evident for all orientations tested under sliding wear conditions. SEM morphologies of the worn surfaces and abrasive papers revealed that the changes in the abrasiveness counterface conditions after few runs, due to clogging of the depression and/or film transfer of polymer, highly determine the m-2BA wear behaviour. Furthermore, during tests, abrasive grains in the SiC paper were remained rigidly attached to the paper. Accordingly, no changes in the wear mechanism due to fracture, pull out, or attrition of abrasive grains was observed and only two-body abrasion process was dominated. AP-orientation exhibited the lowest wear rate (best abrasive performance) compared to P- and N-orientation. Fibers in AP-orientation enhanced by filling the fiber-matrix gabs with fine debris and this in turn increases the rigidity of the CSM against the side forces leading to less fiber damage. Wear mechanisms were categorized after microscopic observation of the abraded surfaces into five main types, i.e. micro-cutting, micro-ploughing, micro-fracture and micro-cracking in the resin, and micro-fatigue. (c) 2006 Elsevier B.V. All rights reserved.