Research of KFRP tool heating drilling based on the cutting-edge force-heat concentration effect and novel tool structure design

Kevlar fiber reinforced plastic (KFRP) is widely used in military industry and aircraft field. Traditional mechanical drilling often leads to defects such as delamination and fiber drawing. The processing technology significantly influences the defects in hole drilling. In this paper, given the high thermal sensitivity of KFRP, a rotary cutting process with induction heating of the tool is proposed, and a corresponding tool structure is designed. Upon application of heat to the tool, the highest temperature of the tool tip is transferred instantaneously to the workpiece material in the cutting area. As the temperature of the material rises, its mechanical properties decline. There is a significant force-heat concentration effect in the advance of the tool. The application of force and heat results in a reduction of thermal damage in the cutting zone, accompanied by a notable decrease in the formation of fiber drawing and delamination. The best surface quality of the hole is achieved when the feed speed V_f = 210 mm/min, the heating temperature T_i = 250 °C.