The Acoustic Emission(AE) signal is monitored in milling operation in order to investigate the relation between progressive tool wear and AE signals. A signal processing technique so called time domain averaging(TDA) is used for the elimination of the influences of the noise imbedded in the periodic signals.
The relation between progressive tool wear and AE signals is investigated by varying the cutting speed, feed, depth of cut and number of insert.
From the measured data, it is observed that the averaged level of AE signal increases at first with an increase of flank wear to a certain critical value ($\bar{F}=0.25~0.3mm$), and then stays almost constant or fluctuates with further increase of the flank wear.
