Synchronously enhanced mechanical and damping properties of Fe-18Ga alloy by mechanical treatment

Abstract

High-damping Fe-18Ga alloy (HDA Fe-18Ga) with enhanced mechanical properties was developed by the treatment successively consisting of hot rolling, water quenching, and tempering. Microstructure characterizations were performed by means of EBSD, SEM, XRD, TEM, and Bitter method. Combining these results with macro-mechanical and damping tests, we systematically studied the effects of deformation and annealing temperature on the mechanical and damping properties of HDA Fe-18Ga, and the relationship between texture and damping was established. It was found with increasing the total deformation, the mechanical strength of the alloy increases, while the plasticity increases firstly and then decreases. This is mainly due to the fact that grain refinement and cracks reduction optimize the strength and ductility of HDA Fe-18Ga during the hot rolling process. As the total deformation reaches a certain level of ∼53%, it lead to dislocation pinning and work hardening resulting in the phenomenon of increased strength and decreased plasticity. When HDA Fe-18Ga plates annealed at 600 °C, the mechanical strength and plasticity were further improved owing to the precipitation of the nano-scale D03 phase. Meanwhile, during the tempering process, the dagger shaped domains decrease, and the 90° maze domains appear, resulting in an increase in the damping capacity of HDA Fe-18Ga.