Excessive sheet thinning and uneven wall thickness distribution of the final product is one of the main disadvantages of single-point incremental forming SPIF. This characteristic of the SPIF process can be improved by extending the mentioned process to a hybrid two-step process consisting of a sequential implementation of bulging and SPIF. An in-depth influencial parameter analysis of SPIF process and the additional bulging using the random forest method resulted in highlighting most influential parameters. In addition, using the artificial neural network method and genetic algorithm, it was possible to define a process window of technological conditions, geometric sizes of tools and trajectories of tool movement, in which a more uniform distribution of the wall thickness of the product is achieved in the sequence of bulging and SPIF process compared to SPIF. To perform SPIF on steels that are more difficult to form, including dual-phase (DP) steels, one of the main objectives of the doctoral thesis was to develop a hybrid machine based on a hydraulic press. As the hydraulic press ram only moves in the vertical direction, the two additional axes of movement required to perform SPIF were achieved by installing linear guides and drives on the press table. In addition, the hybrid two-step forming was carried out without reclamping the workpiece between the two forming steps, which resulted in higher productivity and greater forming accuracy, as both the human influence and the influence of reclamping were eliminated.
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