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

为了使这些形状记忆合金有资格用于新材料密集型应用（例如桥梁和摩天大楼的阻尼元件），铁基形状记忆合金（SMA）腐蚀行为的基础知识至关重要。特别是Fe-Mn-Al-Ni合金，作为最有前途的铁基合金体系之一，在初步的试验中显示出很高的腐蚀敏感性。为了弥补目前研究的不足，本项目将对Fe-Mn-Al-Ni合金的基本腐蚀机理进行研究。此外，铬替代铁和铝将改善腐蚀行为。因此，应该获得合金系统的钝化，这必须保证在表面层被马氏体转变损坏的情况下再钝化。此外，在碱性和酸性溶液中的腐蚀实验将进行资格SMA在土木工程中的各种应用。

A fundamental knowledge of the corrosion behavior of iron-based shape memory alloys (SMAs) is crucial in order to qualify these SMAs for new material intensive applications such as damping elements for bridges and skyscrapers. Especially Fe-Mn-Al-Ni, as one of the most promising iron-based alloy systems, shows a high susceptibility to corrosive attack in preliminary tests. In order to tackle current research gaps, the fundamental corrosion mechanisms of Fe-Mn-Al-Ni will be investigated in this project. Moreover, the corrosion behavior will be improved by the substitution of chromium for iron and aluminum. Thereby a passivation of the alloy system should be obtained, which has to guarantee repassivation in case the surface layer gets damaged by the martensitic transformation. Furthermore, corrosion experiments in alkaline and acid solutions will be carried out to qualify the SMA for diverse applications in civil engineering.