A deburring strategy in drilled hole of CFRP composites using EDM process

Carbon fiber reinforced plastic (CFRP) composites are highly promising materials for applications in the aeronautic and aerospace industry due to their superior strength-to weight and stiffness-to-weight ratios. Drilling of CFRPs composites is an important machining operation in the aerospace industry. However, during drilling of CFRPs, the formation of burrs are always severe shortcomings. In most machining processes, burrs are an undesired by-product cause many problems in assembly, inspection, process automation and precision component operation. To address this problem, this study introduced electrical discharge machining (EDM) as a deburring method for removal of burrs which are generated during drilling of CFRP composites. Four types of cylindrical tool namely copper, steel, brass and aluminium were used as the electrode for deburring. Deburring was carried out at various capacitance and time with different electrode materials. Experimental results demonstrated that the generated burrs of the drilled hole were successfully removed by the proposed deburring method. The copper electrode proved the better performance than others electrode in terms of deburring time and material removal rate. On the other hand aluminium electrode obtained lowest performance. The suggested deburring technique is effective for removal of the drilling burrs in conductive materials regardless of their hardness, because of the EDM deburring uses electrical discharge and its thermal energy without mechanical contact between the tool and workpiece.