抄録
In this study, influence of coating material on the curl diameter of chip in tapping of AISI 304 were investigated. In turning where chip is not ejected thorough flute, friction characteristic of AlCrN coating was better than TiN. However in tapping, both of the average torque and thrust using AlCrN was the largest. The curl of chip of tapping using AlCrN was larger than that of TiN and CrN. The chip curl diameter was larger than the diameter of an inscribed circle at cross section of the flute. Therefore ejection resistance of chip might cause an increase of torque in tapping. Tendency of curl of chip in turning was similar with that of tapping. In tapping, chip clogging lead to breakage. Hence, it is important to investigate the chip curl tendency in advance.
