Research on the variable parameters of each pass in multipass single-point incremental forming

In a study of multipass incremental forming, the same parameters are mostly used for all passes, and the parameters are unchanged in each pass. There are few reports on the use of different parameters in each forming pass. In this study, a cone-shaped part with a forming angle of 70° is selected as the research object, and the different changes of the forming parameters, such as multipass angle interval, tool radius, and axial feed, in each pass are investigated. First, a multipass incremental forming model is developed to analyze the influence of the forming parameters in each pass on the stress, strain, and section thickness of the part. Second, an orthogonal test is designed to analyze the primary and secondary orders of the three sets of parameters and the optimal level combination. Finally, a numerical control experiment is carried out to verify the validity of the model and the accuracy of the simulation results. The sink defects are reduced by adjusting the forming depth of the path. The results show that the primary and secondary orders of the three sets of forming parameters are the tool radius, axial feed, and pass angle interval. The optimal horizontal combination is that the tool radius is constant at 4 mm; the axial feed values are 0.5, 1.0, and 1.5 mm; and the pass angles are 50°, 60°, and 70°. The forming quality and efficiency are improved by selecting the appropriate forming parameters.