Iron-based Shape-Memory-Alloys (SMAs), especially Fe-Ni-Co-Al-based SMAs, are characterized by outstanding functional properties. These can be exploited in seismic protection structures or other areas because of their low material cost, good cold workability and high strength. Thermomechanical treatments as well as thickness reduction of the material affect the crystallographic texture and grain size evolution of cold rolled Fe-Ni-Co-Al-X (X=NbB, TaB, Ti, TiB) SMAs and their functional properties. With a thickness reduction from 90% and higher, the Fe-Ni-Co-Al-X SMAs show a microstructure with a combined Goss-(110)[001] and Brass-(110)[112] texture after recrystallization heat treatment. The higher the degree of reduction the more Goss-texture is present, which has a huge impact on the mechanical properties.

In this work the thickness reductions of 92% and 94% were considered for the Fe-Ni-Co-Al-Ti-B SMA following cold rolling. The material was first homogenized, then cold rolled to 92% and 94%, followed by 1300°C/30min solution annealing for recrystallization and dissolution of the brittle secondary β-phase. Finally, samples were aged by 600°C/4h to form nanoscale γ'-precipitation particles, which are of paramount importance for the thermoelastic behavior. Different recrystallization heat treatments were conducted in order to assess the evolution of the grain size and the texture. Finally, the mechanical properties of textured samples were investigated with focus on functional fatigue and the 2-way effect.