1.1. Experimental set-up in a CNC lathe showing an AE sensor mounted on the tool holder (taken from Hu et al., 2008) 7
1.2. AE-FFT intensity (high and low frequencies) with cutting time for insert F 9
1.3. AE-FFT at different time periods for insert F during the failure pass: (a) first, (b) second, (c) third and (d) last 25 per cent cutting time of the entire machining pass 10
1.4. AE-FFT amplitude comparisons in the four sub-periods during the coating failure pass of insert F 11
1.5. Illustration of the short-time Fourier transform (STFT) method (from Lu et al., 2010) 12
1.6. Raw AE signal for insert A at: (a) initial cutting pass and (b) tool failure pass 13
1.7. AE-RMS amplitude during initial cutting ...