Фазовая диаграмма системы Tc-V

К оглавлению: Другие диаграммы (Others phase diargams)

Tc-V (Technetium-Vanadium) J.F. Smith Tc is one of the elements with negligible natural abundance. Thus, the supply of Tc is limited to that which has been formed in nuclear reactors. The Tc from this source tends to have a variable and rather high interstitial impurity control in the form of 0.5 to 5 wt.% oxygen [67Koc]. As a result of the limited supply of Tc, studies relating to Tc alloy systems are limited in number. With regard to the Tc-V system, only [68Koc] have proposed a phase diagram. [69Koc] studied the superconductivity of a 30 at.% V alloy that was first equilibrated at 1500 C and then annealed for various periods at temperatures below the decomposition temperature of the d phase. Their results showed that two superconducting transitions could be observed, one associated with a matrix phase and the other with a precipitate phase. These transitions diverged with lengthened annealing time, with one increasing and the other decreasing. It appears that the diffusion kinetics of the solute partition between the matrix and precipitate phases were responsible for the apparent anomalies and that it would take prolonged annealing at temperatures immediately below the eutectoid decomposition of the d phase to actually achieve the equilibrium which [69Koc] did not attain with a few hours' anneal. 62Ost: D.O. van Ostenburg, D.J. Lam, H.D. Drapp, and D.E. MacLeod, Phys. Rev., 128, 1550-1554 (1962). 67Koc: C.C. Koch and G.R. Love, J. Less-Common Met., 12, 29-35 (1967). 68Koc: C.C. Koch and G.R. Love, J. Less-Common Met., 15, 43-58 (1968). 69Koc: C.C. Koch and G.R. Love, Trans. Am. Inst. Min. Met. Eng., 245, 1957- 1962 (1969). Published in Phase Diagrams of Binary Vanadium Alloys, 1989. Complete evaluation contains 1 figure, 3 tables, and 7 references.