Alloys Tantalum

Nitrogen and carbon are the most potent solutes to obtain high strength in refractory metals (55). Particulady effective ate carbides and carbonitrides of hafnium in tungsten, niobium, and tantalum alloys, and carbides of titanium and zirconium in molybdenum alloys. 

Priceman, C. and Soma, L., Development of Fused Slurry Silicide Coatings for the Elevated Temperature Oxidation Protection of Niobium and Tantalum Alloys, Report AFML-TR-68-210, Sylvania Electric Products Inc., Dec. (1968)... 

Babitzke, H. R., Siemens, R. E., Asai, G. and Kato, H., Development of Columbium and Tantalum Alloys for Elevated-Temperature Service, Bureau of Mines Report of Investigations 6SSS, US Department of the Interior, (1964)... 

Tantalum and tantalum alloys react with hydrogen, nitrogen and oxygen at temperatures above 300°C. Hydrogen is dissolved in the metallic matrix above 350°C and evolved at higher temperatures of about 800°C . The dissolved hydrogen embrittles the tantalum and its alloys. This effect can be used to prepare tantalum powder. 

Other Tantalum alloys It has been observed that the presence of a small amount of iron or nickel, for example, in a tantalum weld makes that site subject to about the same acid attack as would be experienced by iron or nickel alone. Galvanic action, as well as simple chemical attack, is undoubtedly involved. 

Schmidt, F.F. and Ogden, H.R., The Engineering Properties of Tantalum and Tantalum Alloys, DMIC Report No. 189, DMIC Batelle Memorial Institute, Sept. 13th (1963)... 

As a result of their hardness, noncorrosiveness, and ductility, tantalum alloys are used to fabricate parts for nuclear reactors, missiles, and airplanes, and in industries where metal with these qualities is required. 

Gold alloys resemble copper alloys. Gold-copper-tantalum alloys have also been made.7... 

Iron undergoes cementation when heated in finely divided iron-tantalum alloy containing about 80 per cent, of tantalum the interior consists of a solid solution, which is bounded by a brilliant external layer the thickness of which increases with rise of temperature and with increase in the duration of heating. Copper and brass have been similarly treated.1... 

Magnesium.—A magnesium-tantalum alloy which contains about 3>5 per cent, of magnesium has been obtained by reducing tantalum pentoxide with magnesium powder in a stream of hydrogen.2... 

Platinum alloys containing from 0 5 to 20 per cent, of tantalum are hard, withstand heat, as well as the action of adds and fused potassium hydrogen sulphate, and are more resistant to the action of aqua-regia than platinum.8 They possess the mechanical properties off platinum-iridium alloys and are less expensive the relative quantities, of tantalum and iridium required to produce the same hardness and mechanical resistance are stated to be 1 5. Platinum-tantalum alloys, hence have been recommended for various purposes in place of platinum or platinum-iridium. Tantalum can also be coated with platinum, andl can then be utilised in high-temperature work. ... 

Fig. 5.12. Relationship between hardness H of solid solution crystals and composition of aluminium-niobium and aluminium-tantalum alloys after melting at different temperature, and limited solubility curves for tantalum in aluminium.

Fig. 1. High-heat-transfer bayonet-style exchangers employing tantalum alloy tubes. Each exchanger uses 104 tubes. (Fansteel)...

The Wacker PdCl2-CuCl2 catalyst is a highly corrosive one, and its use requires special vessels and apparatus, such as titanium or tantalum alloys. Heteropolyacids have been used as alternative noncorrosive reoxidants of palladium for a variety of organic transformations,410 for example in reaction (155).411... 

A magnetic cell separator was constructed on a Si wafer to separate cells that were labeled with paramagnetic beads (FeO nanocrystals 50 nm) from unlabeled ones. The magnetic force was generated from thin magnetized wires (10 pm wide, 0.2 pm thick) formed by depositing a cobalt-chrome-tantalum alloy in pre-etched 0.2-pm-deep trenches. These wires were parallel and were oriented at 45° to the hydrodynamic flow direction of cells [278]. 

Tantalum alloys are used in artificial knees as well as hips and other joints. IMAGE COPYRIGHT 2009, VADIM KOZLOVSKY. USED UNDER LICENSE FROM SHUTTERSTOCK.COM. 

Tantalum is also used in many different alloys. An alloy is made by melting and mixing two or more metals. The mixture has properties different from those of the individual metals. Tantalum alloys are used in laboratory equipment, weights for very precise balances, fountain and ballpoint pen points, and tools that have to operate at high speeds and temperatures. 

Another application for tantalum alloys is in medical and dental applications. The metal has no effect on body tissues. It is used in artificial hips, knees, and other joints. Pins, screws, staples, and other devices used to holds bones together are also made of tantalum alloys. 

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