Experimental investigation of heat-assisted CFRTP drilling with an industrial robot

Abstract

Recently, there has been a particularly significant increase in interest in carbon fiber reinforced thermoplastic (CFRTP), given their potential as an alternative to conventional thermosetting CFRP in the aerospace and automotive industries. Robotic-based machining is emerging as an attractive alternative to on-site production of large and complex parts used. The machining temperature significantly impacts the drilling performance of CFRTP, making it imperative to carefully monitor and analyze this parameter due to their temperaturedependent properties. By applying heat to the workpiece, the cutting force can be significantly reduced during the drilling process. This addresses the drawbacks of robotic machining, which has low structural stiffness and can improve machinability. Therefore, to investigate the effects, this paper proposed heat-assisted CFRTP drilling process in a robotic machining system. The machining temperature of the exit hole was investigated under various machining conditions, and the internal structure of the drilled hole was subsequently analyzed. The results show that heat-assisted machining can improve the machining performances and circularity of the hole by up to maximum 6.1 % in the robotic drilling process. Furthermore, it was confirmed that fibers aligned within the drilled hole wall in high temperature machining, reinforcing the machined surface of the hole, and the maximum tensile stress increased by up to 13.06 % before and after heating.