Monitoring the tool wear, surface roughness and chip formation occurrences using multiple sensors in turning

• Tool condition has been monitored using acoustic emission and vibration sensors.
• Flank wear and surface roughness have been measured from raw signal fluctuation.
• Chip formation types have been investigated from the variation of signal pattern.
• Effect of change the cutting condition has been observed from the trend of signal.

Tool wear, chip formation and surface roughness of workpiece under different cutting conditions have been investigated in machining using acoustic emission (AE) and vibration signature in turning. The investigation has shown that the AE and vibration components can effectively respond to the different occurrences in turning including tool wear and surface roughness. The AE has shown a very significant response to the tool wear progression whereas the resultant vibration (V) represented the surface roughness in turning. The vibration components Vx, Vy and Vz described the chip formation type and are found to have the most significant response to the change of feed, depth of cut and cutting speed respectively. The amplitude of vibration components, Vx, Vy and Vz increased with the increase of feed rate, depth of cut and cutting speed respectively. Even though the frequency of different signal components fluctuated at the different stages of tool wear and at different cutting conditions, the frequency of vibration components was always within a band of 98–40 kHz, and the AE has varied between 51 kHz and 620 kHz.