Local atomic and crystal structure of rapidly quenched TiNiCu shape memory alloys with high copper content

Abstract This study aims to reveal features of the local crystal structure and environment in the quasi-binary TiNi–TiCu alloys containing 25 – 40 at.% Cu, by X-ray diffraction and EXAFS spectroscopy. The alloys were produced in an amorphous state by the melt-spinning technique and then crystallised by isothermal and electropulsing treatment. It was shown that Ni local structure is more disordered in comparison with Cu local environment, which is closer to the conventional crystallographic structure. An increase in the Cu content resulted in the magnification of the disordering in the nearest local environment, around both the Ni and Cu atoms, consisting of Ti atoms. No noticeable effect of the annealing rate on the local structure was found.