Tribological studies of polyester reinforced with CSM 450-R-glass fiber sliding against smooth stainless steel counterface

Experimental investigations have been undertaken on chopped strand mat (CSM) 450-R-glass fiber reinforced polyester (CGRP) composite to study its tribological performance. Friction and wear tests were carried out using pin-on-disc configuration under dry sliding contact conditions. In the present work, tribological characteristics of CGRP composite were measured in three principal sliding directions relative to the chopped glass mat orientation in the composites. These are parallel direction (P), anti-parallel direction (AP), and normal direction (N). The effect of various experimental test parameters such as applied loads, sliding distances, and sliding speeds was studied. Scanning electron microscopy (SEM) is performed on worn surfaces to categorize the wear failure mechanisms. Friction and wear results are presented as a function of normal loads, sliding velocities, and sliding distances for P-, AP-, and N-orientations. The results of friction and wear, in general, are strongly influenced by all the test parameters. The highest wear rate is observed when sliding took place in N direction at all speeds tested (1.7, 2.8, and 3.9 m/s), about two orders of magnitude of AP and P directions. On the other hand, the lowest wear rate is exhibited when sliding took place in AP direction at higher speed level (2.8 and 3.9 m/s). At lower speed, (1.1, 1.7, and 2.2 m/s) P-orientation gave lower wear rate. The normal orientation shows 25-55% higher friction coefficients than those obtained for other orientations, i.e. P and AP. Although the sliding took place against smooth stainless steel counterface, the SEM microphotographs showed various mechanisms of abrasive wear nature, i.e. fiber fracture, fragmentation, and peeling off, and microcrack initiation in the matrix and debris formation.