Comparative analysis of the machining temperatures of an end mill and a novel tool in the orbital drilling of CFRP composites

The defects and rejections caused by the combined action of thrust force and cutting heat impede the wide application of carbon fiber-reinforced plastic (CFRP). To study the cutting temperature of two kinds of tools in the orbital drilling of CFRPs, a cutting force model and a heat transfer model were proposed in this research. The three-dimensional heat transfer equation in polar coordinates was established to predict the temperature inside the workpiece and was solved with the finite difference approach. The cutting edge on the bottom of the tool is the main cause of the thrust force, and due to the accumulation of cutting heat, the processing temperature at the exit is higher. The results show that the predictions of the model coincide with the experimental data and that the model can predict the temperature field inside the workpiece in the process of orbital drilling. The novel orbital drilling and reaming tool can effectively reduce the processing temperature of orbital drilling.