Modeling and experimental analysis of the mechanism of micro-burr formation in micro-end-milling process

The micro-burr formation mechanism in the micro-end-milling of microstructure grooves made of Al2024-T6 aluminum alloy using tungsten-carbide tool was investigated in this paper. The three-dimensional finite element model of the micro-end-milling of microstructure grooves was developed to dynamically simulate the micro-burr formation process. The mechanism of micro-burr formation was analyzed with variant ratios of feed to tool edge radius and the effect of cutting parameters and various tool edge radii on the micro-burr formation dynamically simulated. Simulation results show that the dimensions of micro-burrs increase with the rise of feed per tooth, cutting depth and tool edge radius, and the tool edge radius and the maximum effective strain are the main factors affecting the dimensions of burrs. The maximum effective strain in micro-end-milling process is much higher than that in the conventional milling process, showing the distinct size effect. Effect of cutting parameters and tool edge radius on the micro-burr formation was obtained through micro-end-milling experiment of microstructure grooves, which verifies the finite element model. The curves showing the relationship between the tool edge radius and the dimensions of top-burrs (burr height and burr thickness) were obtained in numerical simulation and experiment respectively, with the maximum error within 9.8%. The experimental results also show that the model is suitable for studying the mechanism of micro-burr formation and predicting the dimensions of micro-burrs.