Cutting temperatures and their effects on the machining behaviour in drilling reinforced plastic composites

Construction parts consisting of modern composite materials made of fiber reinforced polymers still need to be machined, whereby special attention has to be paid to the machining quality. The machining quality implies dimensional accuracy as well as a defect-free peripheral zone. Machining defects often occur as a consequence of excessive mechanical loads, which are often caused by wrong process conditions. Besides mechanical loads, the thermal influence on the composite material, which is induced by the cutting process itself, has to be considered as crucial. According to the thermo physical material properties of fiber reinforced polymers the boundary conditions differ from the machining of metals. Especially in drilling operations the heat removal is difficult, when dry machining is employed. Here, temperature measurements in drilling polymer composites are introduced and moreover the machining defects, which occurs according to the process temperatures, are presented.