Micro-milling: Simulation of surface generation and experimental analysis of surface roughness

Micro-milling is a flexible and economical alternative for manufacturing precision miniature components with three-dimensional geometries across a wide range of materials. Meanwhile, in recent years, miniaturized machine tool system has attracted much research. As a result, we built a miniature 3-axis numerical control milling machine tool system with a high speed air turbine spindle and conducted a series of experiments. In this paper, a 2D model of surface generation is proposed based on the minimum cutting thickness. Through simulating the surface topography and computing the arithmetic surface roughness, R_a, the relationship among the surface roughness, the feed per tooth, as well as the cutter geometry is obtained. This model is validated by means of experiments. In order to characterize the surface quality produced by the micro-milling based on the miniaturized machine tool and investigate the factors affecting surface roughness, a surface roughness prediction model, which includes the effects of cutting speed, feed, depth of cut, and the interaction between the two, is established using the experimental design and regression analysis method. Using the model, the influence of the cutting parameters on surface roughness is analyzed and the optimum cutting parameter sets are found.