Titanium alloys electrical resistivities

Titanium alloyed with niobium exhibits superconductivity, and a lack of electrical resistance below 10 K. Composition ranges from 25 to 50 wt % Ti. These alloys are P-phase alloys having superconducting transitional temperatures at ca 10 K. Thek use is of interest for power generation, propulsion devices, fusion research, and electronic devices (52). 

Contact with steel, though less harmful, may accelerate attack on aluminium, but in some natural waters and other special cases aluminium can be protected at the expense of ferrous materials. Stainless steels may increase attack on aluminium, notably in sea-water or marine atmospheres, but the high electrical resistance of the two surface oxide films minimises bimetallic effects in less aggressive environments. Titanium appears to behave in a similar manner to steel. Aluminium-zinc alloys are used as sacrificial anodes for steel structures, usually with trace additions of tin, indium or mercury to enhance dissolution characteristics and render the operating potential more electronegative. 

Fig. 3.3 Temperature dependences of the electrical resistivities, p, of unalloyed titanium and four Ti-AI alloys showing the tendency for ppIdT to shift from strongly positive to weakly negative with increasing aluminum content [Moo73].

Col74] Collings, E.W., Anomalous Electrical Resistivity, bcc Phase Stabihty, and Superconductivity in Titanium-Vanadium Alloys, Phys. Rev., Vol 9,1974, p. 3989-3999... 

Ike88 Ikeda, M., Komatsu, S.-Y, Sugimoto, T., and Kamei, K, Negative Temperature Dependence of Electrical Resistivity in Ti-Mo Binary Alloys, Proc. Sixth World Conf on Titanium, I (Cannes, Prance, 6-9 Jime 1988), Les Editions de Physique, 1988, p. 313-318... 

Note Thermal conductivity and electrical resistivity were determined using the Kohlrausch apparatus. Thermal conductivity values accurate within 5% are obtained by the Kohlrausch mediod. Source R. Taylor and H. Groot, Thermal Conductivity of Titanium and Titanium Alloys, Thermophysical Properties Research Laboratories, Purdue University, 1986... 

Uses. In spite of unique properties, there are few commercial appUcations for monolithic shapes of borides. They are used for resistance-heated boats (with boron nitride), for aluminum evaporation, and for sliding electrical contacts. There are a number of potential uses ia the control and handling of molten metals and slags where corrosion and erosion resistance are important. Titanium diboride and zirconium diboride are potential cathodes for the aluminum Hall cells (see Aluminum and aluminum alloys). Lanthanum hexaboride and cerium hexaboride are particularly useful as cathodes ia electronic devices because of their high thermal emissivities, low work functions, and resistance to poisoning. 

Ruthenium alloyed to platinum, palladium, titanium and molybdenum have many apphcations. It is an effective hardening element for platinum and palladium. Such alloys have high resistance to corrosion and oxidation and are used to make electrical contacts for resistance to severe wear. Ruthenium-palladium alloys are used in jewelry, decorations, and dental work. Addition of 0.1% ruthenium markedly improves corrosion resistance of titanium. Ruthenium alloys make tips for fountain pen nibs, instrument pivots, and electrical goods. Ruthenium catalysts are used in selective hydrogenation of carbonyl groups to convert aldehydes and ketones to alcohols. 

Use Hardener for platinum and palladinum in jewelry, electrical contact alloys, catalyst, medical instruments, corrosion-resistant alloys, electrodeposited coatings, nitrogen-fixing agent (experimental), solar cells (experimental) the oxide is used to coat titanium anodes in electrolytic production of chloride the dioxide serves as an oxidizer in photolysis of hydrogen sulfide. 

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