Molybdenum metallurgy

Incandescent Lamps, Electronic Tubes, and Resistance Elements. Articles fashioned in any form from molybdenum and tungsten usually fall within the bounds of powder metallurgy. These metals normally are first produced as a powder. Both molybdenum and tungsten are used as targets in x-ray tubes, for stmctural shapes such as lead and grid wires in electron tubes, and as resistance elements in furnaces. 

The basic corrosion behaviour of stainless steels is dependent upon the type and quantity of alloying. Chromium is the universally present element but nickel, molybdenum, copper, nitrogen, vanadium, tungsten, titanium and niobium are also used for a variety of reasons. However, all elements can affect metallurgy, and thus mechanical and physical properties, so sometimes desirable corrosion resisting aspects may involve acceptance of less than ideal mechanical properties and vice versa. 

C. K. Gupta, Extractive Metallurgy of Molybdenum, CRC Press, Florida, USA, 1992. 

Molybdenum is malleable and ductile, but because of its relatively high melting point, it is usually formed into shapes by using powder metallurgy and sintering techniques. 

Perello, J.A., Fleming, J.A., O Kane, K.P., Burt, P.D., Clarke, G.A., Himes, M.D., Reeves, A.T. 1995. Porphyry copper-gold-molybdenum deposits in the Island Copper cluster, northern Vancouver Island, British Columbia. In Schroeter, T.G. (ed.). Porphyry Deposits of the Northwestern Cordillera of North America. Canadian Institute of Mining, Metallurgy and Petroleum, Special Volume 46, 214-238. 

In preparing solid platinum from its powder, Wollaston foreshadowed modern methods of powder metallurgy, by which the powders of refractory metals, such as tungsten, molybdenum, tantalum, and columbium, can be fabricated into useful articles (84, 86). 

In metallurgy, niobium is classified as a refractory metal, along with tungsten, tantalum, and molybdenum. A comparison of the four metals is given in the accompanying table. 

The compacted powder mixtures of these materials are usually liquid phase sintered with Ni or Ni-Co binder metal alloys. The microstracture features a core-and-rim stracture of the hard phase with a molybdenum- and carbon-rich (Ti,Mo)C rim and a titanium- and nitrogen-rich Ti(C,N) core. This microstructure can be made visible in the SEM (Figure 16). The metallurgy of the phase reactions is not... 

Powder metallurgy techniques have been used to produce a very wide range of compacts containing molybdenum disulphide in such metals as mixed iron-palladium, iron-platinum , tantalum , iron-tantalum , molybdenum-tantalum , and molybdenum-niobium . The concentration of molybdenum disulphide in these compacts has risen to 90% compared with less than 35% in earlier materials. Composites containing nickel were found to be unsatisfactory because of high friction and wear. 

Prokudina, V.K., Kalikhman, V.L., Golubnichaya, A.A., Borovinskaya, I.P. and Merzhanov, A.G., Synthetic Molybdenum and Tungsten Disulfides, Soviet Powder Metallurgy and Metal Ceramics, 17, 450, (1978). 

Kalamazov, R.V., Ibragimov, A.T., Kal kov, A.A. and Bogomolov, A.M., Reactions of Molybdenum Disulfide with Gases and Water Vapour, Soviet Powder Metallurgy and Metal Ceramics, 22, 27, (1983). 

Koval chenko, M.S. and Yulyugin, V.K., Densification Kinetics of Porous Metai Based on Molybdenum Disulfide in Hot Pressing, Soviet Powder Metallurgy and Metal Ceramics, 19, 324, (1980). 

Sandia National Laboratories Annular Core Research Reactor (ACRR) is a 2 megawatt, pool-type research reactor that is used to produce isotopes for medical applications. The ACRR and Sandia s nearby hot cell facility, along with Los Alamos National Laboratory s (LANL) chemistry and Metallurgy Research Facility, have been chosen for US domestic production of molybdenum-99 and related medical isotopes. 

X-Ray. X-ray analysis data, summarized in Table 1, shows that the deposit contains 20.8 % nickel (Ni) plus vanadium(V), and 8.8 % sulfur (S). Interestingly, the data reveals only 2.5% of each of the primary catalyst components aluminum (Al) and molybdenum (Mo) hence, it is unlikely that carryover of the catalyst contributes significantly to the accumulation of V and Ni. Furthermore, it appears unlikely that major amounts of V and Ni derive from the reactor metallurgy, as the deposit contains only 1.7% iron (Fe). The rejection of "vanadium-and nickel-sulfide"[5] from the catalyst surface may account for the high amounts of V, Ni, and S. 

The method involving the Mo-V-P acid has been used in determinations of phosphorus in biological tissues [127], plant material [128], fruits [129], fish products [130], foodstuffs [131], phosphate minerals [132], cast iron and steel [133,134], niobium, zirconium and its alloys, titanium and tungsten, aluminium, copper, and white metal [135], nickel alloys [134,135], metallurgy products [136], molybdenum concentrates [137], silicon tetrachloride [7], cement [138], and lubricants[139]. The flow injection technique has been applied for determining phosphate in minerals [140] and in plant materials [141]. 

S., A mass-spectrometric investigation of the evaporation of molybdenum and tantalum diselenides, Sov. Powder Metallurgy Met. Ceram., 15, (1976), 866-868. Cited on pages 345, 346, 351, 544. 

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