Mechanical stabilization of martensite in Cu–Ni–Al single crystal and unconventional way to detect it

0495569 - FZÚ 2019 RIV CH eng J - Journal Article
Heczko, Oleg - Vronka, Marek - Veřtát, Petr - Rameš, Michal - Onderková, Kristýna - Kopecký, Vít - Krátká, P. - Ge, Y.
Mechanical stabilization of martensite in Cu–Ni–Al single crystal and unconventional way to detect it.
Shape Memory and Superelasticity. Roč. 4, č. 1 (2018), s. 77-84. ISSN 2199-384X. E-ISSN 2199-3858
R&D Projects: GA ČR GB14-36566G; GA ČR GA17-00062S; GA MŠMT LM2015087
Institutional support: RVO:68378271
Keywords : structure * martensite microstructure * mechanical stabilization * transformation detection by magnetic measurement
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)

The microstructures and transformation behaviour of self-accommodated and mechanically stabilized martensite of Cu69.4Ni3.4Al27.2 (at.%) single crystal were investigated by optical microscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and magnetometry. XRD and TEM analyses showed the presence of both 2H and 18R phases in self-accommodated martensite. The mechanical compression of martensite (& 100 MPa) increased markedly the transformation temperature to austenite, i.e. resulting in significant mechanical stabilization of martensite. The 18R phase disappeared after the compression. This reveals the important role of 18R phase in transformation behaviour of Cu–Ni–Al alloy. Furthermore, we demonstrate that thermo-magnetic measurement is suitable method to analyse the martensitic transformation even for diamagnetic material.
Permanent Link: http://hdl.handle.net/11104/0289788