Tool Condition Monitoring in Microturning of Aluminium Alloy using Multiple Sensors

In the present work, an attempt has been made to monitor the tool condition status during microturning of aluminium alloy (AA 6061) using multiple sensors such as cutting force dynamometer, acoustic emission (AE) and accelerometer. The tool wear (nose wear) is correlated with surface roughness (R-a), chip width, thrust force (F-x), tangential force (F-y), feed force (F-z), AERMS and vibration signals. It is observed that R-a, chip width and cutting forces are increased with increase in the tool wear. Among the cutting forces, the tangential force (F-y) is found to be more sensitive to the tool wear status compared to that of the thrust force (F-x) and feed force (F-z). From the signal analysis, it is observed that during machining with good tool condition, the dominant frequency of the AERMS and vibration signals are found to be 81 kHz-110 kHz and 2.07 kHz-3.84 kHz respectively, whereas with the worn out tool the dominant frequencies are shifted to higher levels. Chip morphological studies indicated that favourable type of chips are formed upto 40 th minute and unfavourable chips are observed from 41 st minute to 60 th minute.