Фазовая диаграмма системы Rb-Ti

К оглавлению: Другие диаграммы (Others phase diargams)

Rb-Ti (Rubidium-Titanium) C.W. Bale As part of a project to determine the corrosive effects of Rb on commercial refractory and nonrefractory metals, [62You] measured the equilibrium concentrations of Mo-0.5 wt.% Ti alloys in liquid Rb at 760, 927, and 1093 C. The results were very scattered. The maximum solubility was reported as approximately 0.0007 at.% Ti at 1093 C and the minimum solubility was approximately 0.0002 at.% Ti at 929 C (and not at 760 C). [62You] also reported oxygen impurity levels of 18 to 64 wt. ppm oxygen at 760 C, 18 to 65 wt. ppm oxygen at 927 C, and 4 to 6 wt. ppm oxygen at 1093 C. It is quite possible the oxygen impurity enhanced the corrosion of Ti (at 760 C, for example) because rubidium titanates should be extremely stable [82Koh]. There are no other published data for this system. By analogy with the other alkali metal-group IVa systems, it is speculated that the system is almost completely immiscible in both the solid and liquid states. If the solubilities are very limited, it follows from thermodynamic calculations that the univariant temperatures in the phase diagram are virtually coincidental with the transition temperatures of the pure components. From vapor pressure calculations, at 2000 C the composition of the gas phase at 1 atm is estimated to be approximately 0.038 at.% Ti in equilibrium with almost pure liquid Ti. 62You: P.F. Young and R.V. Arabian, USAEC Contract AT (04-3)-368; AGN-8063 ( 1962). 82Koh: R.Kohli, Material Behavior and Physical Chemistry in Liquid Metal Systems, Plenum Press, New York, 345-350 (1982). Published in Bull. Alloy Phase Diagrams, 10(2), Apr 1989, and Phase Diagrams of Binary Titanium Alloys, 1987. Complete evaluation contains 1 figure, 1 table, and 3 references. 1