Feed Cutting Force Analysis Using Discrete Wavelet Transform in Drilling of Aluminium Matrix Composite

This paper presents an analysis of the cutting forces during the drilling of a ceramic fibre-reinforced aluminium matrix composite. The machining was carried out under dry drilling conditions and with minimum lubrication of the cutting zone. The mean values of the feed force and the ratio of this mean to the force amplitude were calculated. This result is the load stability coefficient was thus obtained. The measured force waveforms were decomposed using a discrete wavelet transform in Matlab. An approximation, which is a filtered force waveform, and a detail, i.e. the noise of the measurement, were obtained. The numerical value of noise and interference was calculated from the ratio of load stability after filtration to load stability before filtration. It was found that the use of oil mist lubrication slightly reduces the average value of the feed force during drilling of the tested composite. The interference affecting the force measurement when drilling with MQL is higher, while the type of Daubechies wavelet compactness does not affect the filtration power.