Investigation and target-oriented improvement of the corrosion behavior of Fe-Mn-Al-Ni-Cr shape memory alloys

• Applicant: Professor Dr.-Ing. Thomas Niendorf
• Subject Area: Metallurgical, Thermal and Thermomechanical Treatment of Materials ; Mechanical Properties of Metallic Materials and their Microstructural Origins
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 447247560

In the first funding period of the project „Investigation and improvement of the corrosion behavior of Fe-Mn-Al-Ni(-Cr) shape memory alloys” (SMAs), the effects of different chromium contents on the microstructure development as well as the corrosive and the mechanical properties were comprehensively analyzed. It was found that the corrosion properties of iron-based SMAs are detrimentally affected by the characteristic martensitic phase transformation. In the second funding period, the corrosion system is now to be adapted to such an extent that the limitations resulting from the phase transformation can be overcome. Two different approaches will be pursued. Based on the results of the first project period, new alloy variants will be investigated that form a stable and repassivating oxide layer that counteracts the negative influence of the phase transformation. The properties will be tested on a new in situ corrosion test stand, which will be installed in a tensile testing machine. At the same time, the possibilities and limitations of active corrosion protection methods will be evaluated focusing on a non-passivating alloy, which was already extensively investigated in the first funding period with respect to the superposition of corrosive conditions and mechanical stress.

• DFG Programme: Research Grants