Study of Nb-Zr-Ti Phase Diagram (Studies of Hard Superconductor, II)

Abstract

Although the critical temperature and the critical field of hard superconductors are determined basically by the intrinsic properties of material, the critical current depends on the internal structure of material such as the magnitude of the localized internal stress due to the dislocation, precipitation, composition fluctuation, etc. Accordingly, a study of superconducting properties of Nb-Zr-Ti ternary alloys requires a phase diagram. In this report, a Nb-Zr-Ti ternary phase diagram at the temperatures of 570°{$~$} 1100°C, at which the eutectoid transformation and the two-phase decomposition occurred, was examined by means of microscopical and X-ray analysis. The isothermal sections at 1100°, 900°, 800°, 700 and 570°C are shown Figs. L 4, 5, 6 and 7.