Reducing roughness of freeform surface through tool orientation optimization in multi-axis polishing of blisk

In the field of multi-axis polishing of blisk, path planning is one of the core contents. It not only determines the polishing efficiency but also affects the polishing accuracy. However, as one of the most important roles, the influences of tool orientation on freeform surface roughness have not been paid enough attention. To address that, a method to reduce the roughness through tool orientation optimization is proposed in this paper. Firstly, the model of polishing freeform surface with abrasive cloth wheel is established to describe the influence of tool orientation on the uniformity of material removal. It is described with the distribution of compression deviation along the contact curve and the trajectory of grain. Based on that, the model of tool orientation optimization is established and solved with the PSO (particle swarm optimization) method. Where, both the deviations of maximum compression and ideal angle are taken as evaluation indicators. At last, the effectiveness of the proposed method is verified with a plane and an open blisk respectively. Besides, the results also show that both the deviation of compression and the angle between tool orientation and feed direction can affect the roughness of polished surface. And the latter is more significant.