Description
Efforts to reduce CO2-emissions of cars and aircrafts by lightweighting require materials with high strength-to-weight ratio. However, these materials are often inherently hard to form due to limited ductility and necessitate high forming forces at room temperature. A possible approach to reduce the forming force and improve the formability is the use of electric current pulses during forming, leveraging the electroplastic effect (EPE). The EPE in metals is known to reduce yield stress and springback, and to allow significantly higher degrees of deformation before fracture [1]. Overall energy input is significantly reduced. However, Joule heating occurs, the magnitude of which depends on the electric energy input. It is difficult to distinguish between the EPE and softening due to Joule heating. Besides mandating special tooling and lubricants, excessive heating can deteriorate the microstructure of materials, for example by coarsening of hardening precipitates in Al alloys. If Joule heating can be reduced to a minimum, temperature-sensitive materials can be deformed.To study the influence of electric pulse length, height, and frequency on the formability of various light metal alloys and steels, we equipped a semi-industrial-scale hydraulic press with an electric system, while controlling for temperature to decouple the EPE from Joule heating. First experimental results show a reduction of flow stress in compression tests for samples pulsed with current. Subsequently, tensile testing and deep-drawing experiments (electrically assisted manufacturing) are planned. TEM will be used to elucidate the mechanisms underlying the EPE in Al, Mg, and Ti alloys as well as steels.
| Period | 21 Jul 2022 |
|---|---|
| Event title | Junior-Euromat |
| Event type | Conference |
| Location | Coimbra, PortugalShow on map |
| Degree of Recognition | International |
Research Field
- Advanced Forming Processes and Components