Abstract
Now the users of composite materials have faced a difficulty to machine them, because knowledges and experiences acquired for conventional materials can not be applied to such new materials, of which machinability is completely different from that of conventional materials. This seems to necessitate fundamental investigation into the cutting mechanism of FRP. In this study, firstly, the chip formation in orthogonal cutting of GFRP of simple continuous fibres has been observed for varied fibre angles. Secondly, the cutting force and the roughness of machined surface are measured in reference to the fibre angles, and the cutting temperature is experimentally obtained by a special device. The cutting force becomes minimum approximately at 30 degree fibre angle and it increases steeply with the increase of fibre angle. The roughness of machined surface exhibits a similar trend to that of cutting force. The cutting temperature in machining GFRP is comparatively higher than that in machining ordinary metals, and it increases more steeply with the increase of cutting speed compared with the case of metal cutting. In addition to it, a mathematical model to estimate the cutting force, which is a function of fibre angle, has been proposed.
