An innovative process combination of additive manufacturing and sheet bulk metal forming for manufacturing a functional hybrid part

The combination of additive manufacturing (AM) and forming offers new opportunities in part and process chain design. To show the potential of this process combination, a gear component with discrete tooth geometry is manufactured by powder bed fusion of metal using a laser beam (PBF-LB/M) and forming. Such gear components are manufactured conventionally in a process chain of several sheet bulk metal forming operations like orbital forming, deep drawing and upsetting. Orbital forming is used to manufacture a tailored blank to increase form filling in the subsequent forming operations. However, challenges are form filling and control of material flow. These severely affect whether the target geometry can be realized. To overcome these limitations, in this work PBF-LB/M is used to manufacture the tooth geometry close to the target on a flat sheet. Subsequently, the three-dimensional part geometry is realized by forming. The advantage is that the orbital forming step is not necessary. With that, the tooth geometry does not depend on material flow. A further benefit is geometric flexibility of additive manufacturing processes. Hence, diversity of variations can be increased over a wide range without additional cost intensive forming tools for each single part geometry. Besides, the potentials and challenges of the approach are discussed. The investigations include characterization of formability of sheet metal and AM material, metallographic analysis and hardness measurement. A process chain for manufacturing hybrid parts is presented and the final part geometry is evaluated by topography measurement. The major finding is that the tooth geometry manufactured by additive manufacturing and forming is closer to the target than for the conventional process chain. Additionally, a comparison of technological and economic advantages is drawn. Finally, an extension of the approach is presented by hybrid parts with additively manufactured structures on both sides of the sheet metal.

Automated summary

The paper introduces the combination of additive manufacturing and forming technologies, demonstrating the potential of this process combination. By using PBF-LB/M for tooth geometry manufacturing and forming, closer results to the target were achieved, saving manufacturing costs and improving production efficiency.