Characterisation of surface micro-topography by power spectral density in high speed precision planar milling of SiCp/Al composite

This paper presents an experimental study in high speed precision planar milling of SiCp/Al composites. Machining tests were carried out on a high speed milling machine (ops 650) by using chemical vapour deposition (CVD) diamond-coated tools. The surface micro-topography was tested by the OLS3000 confocal laser scanning microscope. The Gaussian filtering method and the least square fitting method were used to treat the measured results. Two methods are compared according to the effect on keeping important original character of the machined surface, as original character of the machined surface such as surface defects affect the surface micro-topography seriously. The treated surface data was analysed using the method of power spectral density. The three-dimensional root-mean-square deviation of the surface S_q was also calculated. The results showed that the least square fitting method is suitable due to its good accordance to the original characters of the surface. Cutting speed is found to be the main factor affecting the value of power spectral density and three-dimensional roughness parameter, while both feed rate and depth of cut have little effect on them.