Promising ferromagnetic Ni–Co–Al shape memory alloy system

Abstract

A system of ferromagnetic β phase Ni–Co–Al alloys with an ordered B2 structure that exhibits the shape memory effect has been developed. The alloys of this system within the composition range Ni (30–45 at. %) Co–(27–32 at. %) Al, undergo a paramagnetic/ferromagnetic transition as well as a thermoelastic martensitic transformation from the β to the β′(L10) phase. The Curie and the martensitic start temperatures in the β phase can be controlled independently to fall within the range of 120–420 K. The specimens from some of the alloys undergoing martensitic transformation from ferromagnetic β phase to ferromagnetic β′ phase are accompanied by the shape memory effect. These ferromagnetic shape memory alloys hold great promise as new smart materials.

Welding and Joining of NiTi Shape Memory Alloys: A Review

“…Gale et al [102] investigated martensitic NiTi and NiAl furnace brazed using Cu as a filler material. Likewise to NiTi, NiAl alloys also exhibit shape memory effect [103]. Although no significant microstructural changes were detected in the NiAl substrate, Ti migration from NiTi lowered the transformation temperatures of the NiTi substrate and thus, austenite was present at room temperature.…”

Martensitic transitions and the nature of ferromagnetism in the austenitic and martensitic states ofNi−Mn−Snalloys

“…Therefore, in the past few years, there has been more research invested in the search for materials exhibiting the MSM effect and having more favorable mechanical properties at the same time. Over the past few years, other MSM alloys, such as Fe-Pt, 8 Fe-Pd, 9 CoNi-Al, 10 Co-Ni-Ga, 11 Fe-Ni-Ga, 12 and Ni-Mn-Al, [13][14][15][16] have been encountered.…”

Magnetically Anisotropic Ni₂MnGa Thin Films: Coating Glass and Si Micro-Cantilevers Substrates

“…Such materials include NiMnGa [2] and other alloys [3][4][5][6][7][8] and are produced by a large variety of techniques, such as arc melting [9], melt-spinning [10,11], sputtering [12][13][14] and Pulsed Laser Deposition (PLD) [15][16][17].…”