Effect of electron irradiation defects on the martensitic transformation characteristics and microstructure of Ni45Co5Mn37In13 alloys

Ni-Co-Mn-In based alloys with magnetically driven shape memory effect have shown its huge potential for applying as the intelligent driver in the spacecrafts. However, the numerous cosmic radiations, especially the electron irradiation with large penetration depth, could seriously harm its' serving stability. Herein, the Ni45Co5Mn37In13 alloys are exposed to the high energy electron irradiation with different fluence to study the phase transition behavior and microstructure evolution in the irradiation process. As a result, we reveal that the electron irradiation could induce dense crystal defects which not only reduce the transition temperature and thus retain the residual austenite in the martensitic matrix, but also destroy the continuity of martensitic laths and the atom arrangement in the twin boundaries. This work has important theoretical significance for understanding the electron irradiation's effect on the martensitic transformation and microstructure of Ni-Co-Mn-In alloys, and is conducive to expand martensitic transformation theory.