摘要
Phase transformations and precipitation mechanisms in Ti<sub>50sub>Ni<sub>25sub>Cu<sub>25sub> material, starting from an amorphous planar-cast ribbon, were studied by in-situ transmission electron microscopy (TEM). On heating, the cubic B2 austenite crystallisation occurs around 470°C after which the orthorhombic B19 martensite is formed on cooling. Annealings up to 700°C yield the identification of Cu<sub>3sub>Ti<sub>2sub> and Ti<sub>2sub>Ni precipitates. These precipitations drastically alter the matrix composition, resulting in the formation upon cooling of the monoclinic B19′ martensite with different types of long-period stacking sequences. Also the B19′ martensite is still recognised in the latter samples.