Science · 2010 · 538 citations · 14 references
Natural SciencesMaterials EngineeringMaterials ScienceMechanical Behavior Of MaterialsMetallic MaterialsMetallurgyAlloysDuctilityMetalsPlastic DeformationStrain EngineeringStrengthening MechanismsFerrous AlloysNi-al AlloysSensor TechnologyShape Memory Alloy DampersShape-memory AlloysTensile Strength
Shape‑memory alloys such as Ni‑Ti and Cu‑Zn‑Al exhibit reversible strains of several percent via superelasticity, but only Ni‑Ti alloys are currently practical for applications. The authors report a ferrous polycrystalline alloy that achieves over 13 % superelastic strain and >1 GPa tensile strength—almost double the strain of Ni‑Ti—while also providing high damping and reversible magnetization, making it a promising high‑damping sensor material.
Shape-memory alloys, such as Ni-Ti and Cu-Zn-Al, show a large reversible strain of more than several percent due to superelasticity. In particular, the Ni-Ti-based alloy, which exhibits some ductility and excellent superelastic strain, is the only superelastic material available for practical applications at present. We herein describe a ferrous polycrystalline, high-strength, shape-memory alloy exhibiting a superelastic strain of more than 13%, with a tensile strength above 1 gigapascal, which is almost twice the maximum superelastic strain obtained in the Ni-Ti alloys. Furthermore, this ferrous alloy has a very large damping capacity and exhibits a large reversible change in magnetization during loading and unloading. This ferrous shape-memory alloy has great potential as a high-damping and sensor material.
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