Influence mechanism of tool cutting geometry on chip formation in experimentally simulating wood sanding

The material removal in wood sanding is associated with the chip formation and flow, which is directly influenced by grits cutting geometries. Hence, typical single grits with conical, triangular pyramid (3 M) and pentagonal pyramid (5 M) cutting geometries were selected to experimentally simulate wood sanding on sugar maple wood (Acer saccharum). The results of dynamic chip formation showed that only 3 M geometry produced discernable continuous chips. Combined with the scratch morphology and the cutting force ratio, more cutting actions occurred for 3 M geometry, while the conical and 5 M geometry induced material compression and better surface quality. According to the established force model and the result of specific energy, the work done by tangential cutting force F_t to compress and densify wood material by the conical and 5 M geometry was similar and even larger than the work done by F_t to make debris caused by the 3 M geometry. Besides, less oscillation of F_t suggested that the 5 M geometry performed more stable negative-rake cutting. It can be concluded that the grit cutting geometry has a notable effect on the chip formation, surface quality and energy dissipation.