Influence of alloy elements (Mo, Nb, Ti) on the strength and damping capacity of Fe-Cr based alloy

Effects of Mo-, Ti- and Nb-substitution for Al on the strength and damping capacity of the Fe-13Cr-4.5Al alloy were investigated by analyzing the mutual relationships among microstructures, strength, internal stress and damping capacity of the alloys. The obtained results show that the substitution of 0.5Mo for 0.5Al improves both the strength and damping capacity of the alloy. While the substitution of 0.5Ti or 0.5Nb for 0.5Al simply improves the strength but reduces the damping capacity of the alloy. The effect of the alloy elements on the strength and damping capacity lies in the fact that the substitution of the alloy elements generates both local internal stress and pin dislocations. Lower average internal stress leads to higher damping capacity of the alloy. The substitution of 0.5Mo for 0.5Al decreases the interactions between the dislocations and the solute atoms while increases the elastic distortions of the crystalline lattice, resulting in the enhancement of both strength and damping capacity.