Experiment on carbon fiber–reinforced plastic cutting by abrasive waterjet with specific emphasis on surface morphology

Abstract

In the machining of carbon fiber–reinforced plastic by abrasive waterjet, the surface morphology of the cutting front directly reflects the processing quality. So in this study, the changes in the topography and surface roughness of the cutting front as a result of variations in five operational parameters, namely, the traverse speed, abrasive mass flow rate, waterjet pressure, standoff distance, and sample thickness, were experimentally studied with the aid of μscan laser confocal microscopy. It was found that periodic stripes and grooves appeared in the traverse direction from observations of three-dimensional surface morphology. And the analysis of the surface roughness revealed that there were three distinct cutting regions along the penetration direction, namely, an initial damage region at the jet entry, a smooth cutting region in the intervening cutting area, and a rough cutting region near the jet exit. According to the three distinct regions in the penetration direction, a three-zone cutting front model was proposed. A high-quality machined surface could be obtained by extending the smooth cutting zone through the appropriate choice of process parameters. Therefore, the influences of the above five parameters on the length of the smooth cutting zone were also investigated, and recommendations are proposed for process control.