Mechanical Deburring of Drilling-Induced Exit Burrs in Carbon Fibre Reinforced Polymer Composites

Abstract

Carbon fibre reinforced polymer (CFRP) composites have excellent specific mechanical properties, which have contributed to the replacement of metallic structural components in high-tech sectors. However, the anisotropic and inhomogeneous properties of CFRPs render them difficult to cut. Burr is one of the main machining-induced macro-geometrical defects in CFRPs. Even though burr does not weaken the resultant strength of the composites (unlike delamination), its removal is time-consuming and costly. The main aim of the present paper is to investigate the efficiency of the mechanical deburring method. Deburring experiments were carried out on unidirectional CFRP, based on a full factorial experimental design using a special solid carbide cutting tool. The effects of feed and cutting speed were analysed using digital image processing and visual evaluation of high-resolution images. The experimental results show that the examined factors seem to have no significant effect on the results over the applied parameter range, because the exit burrs were successfully removed at each parameter setting. Furthermore, during the deburring process, the formation of a significant amount of chamfers was observed. Since the size of the chamfers depends on the size of delamination-induced material deformation and process control, it should be either compensated for or monitored in the future to develop a more reliable deburring process.