Effect of heat treatment on the precipitation hardening in FeNiCoAlTaB shape memory alloys

In order to obtain optimal mechanical properties, the effect of heat treatment on the precipitation hardening in multicomponent Fe-based shape memory alloys (containing Ni, Co, Al, Ta, B) was studied. The polycrystalline material was investigated after application of three different processing schemas: slowly cooled, quenched and subsequently annealed with various aging conditions. The study was carried out using synchrotron X-ray diffraction along with mechanical tests, revealing the evolution of strengthening phases. As a result an optimum heat treatment for 10 h at 700°C was established yielding an optimal mechanical response.