Study of ferromagnetic Co–Ni–Al alloys with thermoelastic L10 martensite

Alloys of the 37–39 at.% Co–32–34 at.% Ni–28–30 at.% Al system, which were prepared by quick spinning-melt quenching and had a microcrystalline structure, were studied using electron microscopy, resistometry and magnetometry. It was shown that the temperature interval of the β(B2) → L10 martensitic transformation depended on the composition and the structural size of the alloys. When 1 at.% Co and 1 at.% Al were replaced by Ni, the temperature interval of the B2 ↔ L10 martensitic transformation increased by 30–60 and 100–110 K, respectively. The martensitic transformation hysteresis width was about 100 K.