A novel thermo-mechanical processing route exploiting abnormal grain growth in Heusler-type Co–Ni–Ga shape memory alloys
C. Lauhoff, T. Pham, A. Paulsen, P. Krooß, J. Frenzel, G. Eggeler, T. Niendorf.
Metallurgical and Materials Transactions A, Springer Science and Business Media LLC,, 53, 4139–4142, (2022)
Heusler-type Co–Ni–Ga shape memory alloys attracted significant scientific attention owing to excellent superelasticity in single-crystalline state. However, due to pronounced anisotropy, polycrystalline Co–Ni–Ga suffers from transformation-induced constraints at grain boundaries and, thus, premature failure upon thermo-mechanical loading. The present study reports on a novel thermo-mechanical processing route. Hot rolling followed by solution-annealing promotes abnormal grain growth, eventually leading to high-performance single-crystalline structures. The procedure proposed offers great potential for a direct microstructure design.