HYDRODYNAMIC MACHINING OF FIBER-REINFORCED COMPOSITES

This paper presents the results of an experimental investigation aimed at studying the applicability of waterjet machining to reinforced pla stics. Representative samples of plastics over a wide range of matrice s and fibers of various thicknesses were chosen. The machined samples were studied under a scanning electron microscope (SEM) for surface ch aracteristics. Some samples were measured for roughness using a stylus profilometer and later non-contact laser holography for confirmation. The SEM study revealed that under conditions of excessive cutting spe ed, high stand-off distance, low water pressure, small nozzle diameter , which are considered nonoptimum, the surfaces displayed signs of fib er debonding, pull-out, matrix chipping, and delamination. Roughness r eadings revealed that surface quality improves with larger-diameter no zzles and at low machining speeds.