Effect of Sc on damping properties, compressive and tensile strength of Fe-Cr-Al alloy

In this study, Fe-21Cr-4Al-based alloys were prepared by Sc addition, and their damping and mechanical properties were analyzed. The microstructure and phase composition were analyzed by XRD, SEM and TEM. The results show that the compressive strength of the alloy increases by 37.4 % under the joint action of the second phase and solute atoms. However, decreased plasticity in alloys reduces the critical crack expansion force, resulting in lower tensile strength. The phase structure and microstructure indicate that the phase composition of the alloy is α-Fe, ScAlO3, Sc2O3 and Sc. Dislocations and Sc-rich phases form inside the alloy and Sc enables the damping of alloys to maintain high values of damping properties even over broad ranges of strain amplitude. Moreover, the damping of alloys rapidly becomes larger under combined ferromagnetic and dislocation damping, reaching a peak damping value of 0.093.