Surface topography in ball end milling process: Description of a 3D surface roughness parameter

In the field of free-form machining, CAM software offers various modes of tool-path generation, depending on the geometry of the surface to be machined. Manufactured surface quality results from the choice of machining strategy and machining parameters. The objective of this paper is to provide a 3D surface roughness parameter that formalizes the relative influence of both machining parameters and surface requirements. This roughness parameter is deduced from simulations of the 3D surface topography obtained after three-axis machining using a ball-end cutter tool. Following a state-of-the-art assessment of surface roughness characterization, this paper will present the model generating these simulations before proceeding with an experimental verification campaign of the pattern left on the machined surface. An analysis of the patterns obtained for various sets of machining parameters serves to highlight those that influence 3D surface topography. The 3D surface roughness parameter is therefore defined according to both an influential machining strategy parameter and the surface description. An illustration will be proposed in the article's final section of an industrial case for which the 3D parameter has been used to determine the machining parameters that lead to the expected level of surface roughness.