Numerical Simulation of Chip Ploughing Volume and Forces in 5-axis CNC Micro-milling Using Flat-end Mills

摘要

It is a challenging task to avoid ploughing effects in micro-milling. When one tooth of the cutting tool crosses the minimum chip thickness boundary, the tool would enter into the ploughing zone with no chip formation. Therefore, it is significant to predict the ploughing volume and forces in micro-milling. In this work, the ploughing mechanism for micro-milling is proposed by considering the minimum chip thickness effects. A 3D chip geometry is developed to calculate chip thickness, ploughing volume and ploughing forces in micro 5-axis flat-end milling with a flat-end mill. The local parallel sliced tool based method is then applied to get cutter-workpiece engagement domain where the cutting flutes entry and exit the workpiece, minimum chip thickness and depth of cut are required to predict ploughing forces. Local parallel sliced method divides the cutting tool into several slices that are perpendicular to the tool axis along the local coordinate system. On each layer, the removal chip area is dividing into ploughing zone and shearing zone by the minimum chip thickness. Ploughing zone is the area as chip thickness is less than the minimum chip thickness. In the shearing zone, chip thickness is larger than the minimum chip thickness. The total chip ploughing volume is obtained by adding all ploughing area along axial direction.