The influence of processing parameters on surface characteristics in micro-milling thin-walled slot on Elgiloy

High-leveled surface integrity which is significantly affected by processing parameters is required for machining military and aviation component. This paper firstly introduces the material (rolled Elgiloy), structure (with thin-walled slot), and machining method (micro-milling) of this component. To present surface structural traits, three-dimensional (3D) fractal dimension Ds based on variance method is proved to be a good index, compared with surface roughness. The micro-milled surface quality and structural characteristics are found to be different in various areas. The feed per tooth is revealed as the key factor that affects surface quality and complexity. Based on two-dimensional (2D) fractal method, trend of surfaces structural traits are evidently observed and found closely related to this processing method. These milled surfaces are then evaluated to be of good isotropy, considering the variance of slop and curvature of profiles. And surface anisotropy is found more sensitive to milling depth. With wavelet transform and 2D fractal method, key spatial frequency bands that affect anisotropy and complexity of the surface are revealed, respectively. The present analysis reveals the relationships between various areas of surfaces, anisotropy, and processing parameters in depth and helps to choose reasonable milling parameters for improving surface quality and complexity.