Effects of Al addition on damping and mechanical properties of Fe–Ga alloy sheet

Extremely low room temperature (RT) ductility and severe discontinuous yielding behavior is a key issue preventing the practical application of Fe–Ga based alloys as structural-functional integration materials in critical fields. Here, we report a combination of Al addition and mechanical treatment that results in RT ductility enhancement of Fe–Ga alloys without discontinuous yielding behavior, while retaining high damping capacities. It was found that the RT ductility of Fe-Ga-Al alloy sheets has a significant increase with increasing Al content and the discontinuous yielding behavior almost disappears, and the enhanced ductility is suggested to originate from the interaction of dislocations and the secondary phase. For Fe82Ga16Al2alloy sheet, the maximal damping value can reach up to ∼0.041, and then damping capacity gradually decreases with increasing Al content but still remains at a high level. The mechanism of damping reduction is suggested to be caused by the limitation of domain wall motion caused by the additional domains generated inside the main domains. This study provides a reference for optimizing the RT ductility of Fe–Ga based alloys while taking into account the functional properties, and is beneficial for promoting the engineering applications of Fe–Ga based alloys as structural-functional integration components.