Abstract
In milling of flexible workpieces, like thin-wall blades, cutting force induced deformation and vibration are great adverse issues which are almost inevitable. Semifinish-finish (SF) hybrid milling is a promising strategy to obtain a high-accuracy and quality surface, which separates the object blade into several layers in the radial direction of the blisk, and then for each layer, from blade tip to root, using SF hybrid milling as a cycle to finish the current layer, and then move to the next layer. However, two extra contradictions are intruduced in process planning: (1) Considering the number of layers: To decrease the machining deformation error, we should increase the number of layers, which however increases the time consumption because of frequent tool path switching between semifinishing and finishing; (2) As to the allowance of semifinishing: To decrease the machining deformation error, we should increase the allowance in semifinishing to enhance stiffness, which however increases tool wear sicne more matearial needs to be removed by the tool. To balance the contradictions, this paper constructs a framework for parameters planning for SF hybrid milling, in which the allowance, number of layers as well as the length of each layer are optimized so that we are able to control the deformation error while maintaining high cutting efficiency. The method is verified by simulation and validation experiments. Compared with traditional non-layering and uniform layering machining, the maximum deformation error by optimized layering machining is reduced by 76.4% and 48.6%, respectively.