Фазовая диаграмма системы Bi-Ti

К оглавлению: Другие диаграммы (Others phase diargams)


Bi-Ti (Bismuth-Titanium) J.L. Murray The equilibrium solid phases of the Ti-Bi system are (1) the bcc (bTi), cph ( aTi), and (Bi) solid solutions; (2) the intermetallic phase Ti3Bi; and (3) the intermetallic phase Ti2Bi, with the composition range 33 to 37 at.% Bi. The Ti-Bi phase diagram has been examined experimentally only for Ti-rich and Bi-rich alloys and is known only approximately. According to [58Aue], the absorption of oxygen by pyrophoric Ti-Bi alloys is so rapid that contamination is unusually difficult to avoid. Moreover, they noted that free Bi was almost always found in their samples, indicating that it is very difficult to achieve equilibrium. For Ti-rich alloys, the only phase diagram study was made by [60Obi], using microscopic examination, X-ray diffraction, and differential thermal analysis. Two reactions were found: L + (bTi) = Ti3Bi at 1340 с 20 C and (bTi) = (aTi) + Ti3Bi at 725 с 20 C. The solubility of Ti in liquid Bi was determined by [65Wee] by chemical analysis of filtered samples of the equilibrated melt. The liquidus between 300 and 700 C was described by log (at. ppm Ti) = 3.4075 - 2230/T, where T is in K. 58Aue: H. Auer-Welsbach, H. Nowotny, and A. Kohl, Monatsh. Chem., 89, 154-159 ( 1958) in German. 60Obi: I. Obinata, Y. Takeuchi, and S. Saikawa, Trans. ASM, 52, 1059-1070 ( 1960). 65Wee: J.R. Weeks, Trans. ASM, 58, 302-322 (1965). Published in Phase Diagrams of Binary Titanium Alloys, 1987, and Bull. Alloy Phase Diagrams, 5(6), Dec 1984. Complete evaluation contains 3 figures, 2 tables, and 8 references. Special Points of the Ti-Bi System