Akademik Məlumat İdarəetmə Sistemi
Metallofizika i Noveishie Tekhnologii, vol.23, no.9998, pp.111-123, 2001 (SCI-Expanded, Scopus)
New multicomponent alloys of the 'AB' and Be-'AB'-Y type general series with the constituent alloy components varied as 'A' = (Ti, Zr, Nb, Hf) and 'B' = (Ni, Cu, Co, Pd, Ag, Al), which are essentially the potential shape memory alloys, have been developed in initially amorphous state by means of the rapid solidification techniques in CECM/CNRS, Vitry and IMPh, N.A.S.U., Kyyiv. Initially bulk amorphous state is needed as the precursor for production of nanostructured materials of the complicated shape and dimension like wires, tubes or sheets. The main objects of this study are mainly TiNi-based shape memory alloys including, first of all, TiNiCu-, TiNiZr- and TiNiHf-based alloy systems which were already found amorphous in the melt-spun condition. We start with well-known ternary Ti32Hf18Ni50, Ti32Zr18Ni50 and Ti50Ni25Cu25 alloy compositions which undergo the reversible martensite transformation with the Af temperature equal to ∼+ 250°C, ∼+150°C and ∼+90°C, respectively. The material structure was controlled by the XRD and TEM/SAD techniques, while the thermodynamic properties were studied by means of DSC measurements. The thermodynamic parameters like the glass transition temperature TG, the crystallization temperature TX (and derivative the glass formation ability ΔT≡[TX - TG] and TG/TM ratio) and crystallization heat ΔHX have been studied versus composition variation.