A chatter mark is formed on machined surfaces when regenerative chatter vibration occurs during end milling. We proposed a method for inverse analysis of chatter vibration information (frequency and phase shift of the regenerative effect) based on two-dimensional discrete Fourier transform of the chatter mark. Here, the proposed method was used to analyze chatter vibration at a higher frequency than in previous research, which occurred at various spindle cutting speeds. The results obtained by the proposed method were compared with those based on tool vibration measured by acceleration sensors. The results confirmed that the proposed method can accurately analyze the vibration information for high-frequency chatter vibration and can clearly capture the variation in vibration information according to the stability lobe diagram.

This study was performed to clarify the effects of the coating film properties on tapping tool adhesion and tapping torque, and the relations between mechanical properties of coating films and results of tapping tests. A series of hole tapping tests in SUS304 stainless steel were performed using non-coated, TiN-coated, DLC-coated, and TiN/DLC-coated taps. The adhesion area on the flank face and the tapping torque were smaller when tapping with coated than with non-coated taps. Spot-like adhesion occurred on the entire flank face of TiN-coated taps. On the other hand, adhesion occurred only near the cutting edge on the flank face of DLC-coated taps and TiN/DLC-coated taps. TiN/DLC coated taps had the smaller adhesion area on the flank face. The adhesion area on the flank face decreased with decreasing ratio of the friction coefficient obtained from friction tests to the peeling critical load obtained from scratch tests of the coating film.