Basic research on cold and warm forging of microparts

The application of metal forming to the manufacturing of microparts is still not widespread. The reason is that the know-how of conventional technologies cannot be simply transferred to the microscale. This is due to so-called size effects, which in cold forging can be observed in terms of effects on material flow, on tribological behavior, and on working accuracy. Scaled experiments reveal that there is a transition from homogeneous to inhomogeneous continuum which can be characterized by the ratio between grain size and part size. For a given ratio, the transition can be shifted by processing at elevated temperatures yielding a more homogeneous deformation, thus improving the accuracy and reproducibility of the microforming process.