Statistical analysis of acoustic emission signals generated during turning of a metal matrix composite

Abstract

Acoustic emission technique (AET) has been used to monitor the progress of tool wear during turning of silicon carbide (20 wt.%) dispersed Al alloy metal matrix composite. Acoustic emission (AE) signals generated beyond a specific cutting distance increase abruptly. Statistical analysis based on assumed β distribution of AE energy showed that skewness and kurtosis vary with cutting time. Comparison of these results with bparameter of amplitude distribution of AE hits presented in an earlier investigation has shown that while b-parameter is useful for monitoring tool wear up to 0.4 mm, skewness and kurtosis can better monitor the wear beyond that. Uncertainty measurement of AE energy for different cutting distances was determined as per ISO GUM. The combined uncertainty for the measurement of AE energy lies in the range of 0.38 to 1.69, with higher values for the cutting distance between 213.8 mm and 454.5 mm. Different parameters such as skewness and kurtosis of the statistical distribution, b-parameter of amplitude distribution and uncertainties can be used in a complimentary manner for comprehensive evaluation of tool wear.