Study on Fractal Characterization Laws of Cutting Force in CNC Turning Aeronautic Aluminium Alloy 7075-T651

Based on the experiment of turning aluminium alloy (7075-T651), the relations between the fractal dimensions of cutting forces with machining parameters are studied. Cutting speed, feed speed and cutting depth are considered as the process parameters. The cutting force in turning aluminium alloy operation are measured and the fractal dimension are calculated using the algorithm of correlation dimension. From main effect plots the fractal dimensions of three directions of cutting forces are reduced with the increase of cutting speed, increased with the increase of cutting depth and insignificant with the increase of feed speed. The mathematic models of fractal dimension of cutting force are developed using response surface methodology (RSM). The results of the ANOVA show that cutting speed and cutting depth have remarkable influence to fractal dimension Dx, Dy and Dz.