CORRELATING TOOL LIFE, TOOL WEAR AND SURFACE-ROUGHNESS BY MONITORING ACOUSTIC-EMISSION IN FINISH TURNING

Experiments have been conducted in an attempt to monitor the changing of workpiece surface roughness caused by the increase of tool wear, through the variation of acoustic emission in finish turning, under different cutting conditions. The signal-processing analysis was done on the raw signal, on the AE(rms) signal filtered using a high bandpass and on the AE(rms) signal filtered using a smaller bandpass. The relationship among several parameters of acoustic emission such as zero crossing rate, mean AE(rms) and standard deviation of AE(rms) was established. The material machined was 1045 steel. The cutting force was also monitored. The results show that acoustic emission can be a good way to monitor on-line the growth of surface roughness in finish turning and therefore can be useful for establishing the end of tool life in these operations. Based on the results obtained pointing out the best acoustic emission parameters to monitor surface roughness, a set-up is proposed to reach to this goal.