Heating alloys

DOT UN 2975 af Th aw 232.00 PROP Silvery-white, air-stable, soft, ductile metal. Attacked vigorously by aq HCl, slowly by H2O, rapidly by steam. Reacts with H2 (3°), N2 (6°), halogens, sulfur, carbon, phosphorus on heating. Alloys with many metals. Props of metal considerably affected by presence of small amount of Th02. D 11.72, mp 1750 30°. A radioactive material. 

In poor yield by heating alloys of arsenic and sodium with alkyl iodides ... 

The Curie point pyrolysers have several advantages when compared to other systems. The TRT is usually short and the heating rate is reproducible. The Teq temperature is accurately reproducible for the same alloy. The contact between the sample and the heated alloy is good, which assures that the heat transfer to the sample is rapid and uniform. On the other hand, the set temperatures can only be discrete and are limited to the values offered by different alloys. Even though the direct contact of the sample with the ferromagnetic alloy offers the advantage of a good heat transfer, it can be a... 

Yttrium is also a deoxidizer of vanadium, and its addition improves the ductility of nodular cast iron. Yttrium oxides increase the resistance of ceramic materials to heating due to an increase in melting temperature. Yttrium hydrate is used as temperature stabilizer both to increase the stability of heating alloys and to moderate neutrons in nuclear reactors (Luckey and Venugopal 1978 Greinacher 1981 Jezowska-Trzebia-towska et al. 1990). 

By heating alloys of sodium and phosphorus with alkyl halides ... 

The input to muffles or radiant tubes is limited by the strength, durability, and conductivity of their wall materials. The great temperature difference across a muffle or tube wall not only reduces its useful life but also causes the products of combustion to exit at a very high temperature, raising the fuel bill. For both reasons, muffle and tube walls are made as thin as practical, using a material that has both high thermal conductivity and resistance to heat. Alloy steels and silicon carbide are the most suitable materials for muffles and radiant tubes. Silicon carbide radiant tubes can withstand higher temperatures and are more resistant to oxidation than nickel-chrome alloy steel tubes, but the latter are less brittle and cheaper. 

Si] Adiabatic calorimetry wit liquid hehum bath Low-T specific heat. Alloys with 3 at.% Si. 

This service test method covers the determination of the resistance to oxidation of nickel-chromium-iron electrical heating alloys at elevated temperatures under intermittent heating using a constant temperature cycle test. This test is used for internal comparative purposes only. 

Birtill JJ, Ridley P, Liddle S, Nunney TS, Raval R. Degradation of methanol and methylamines to carbon over heated alloy surfaces. Ind Eng Chem Res 2001 40 553-7. 

Figure A2.5.21. The heat eapaeity of an order-disorder alloy like p-brass ealeulated from various analytie treatments. Bragg-Williams (mean-field or zeroth approximation) Bethe-1 (first approximation also Guggenheim) Bethe-2 (seeond approximation) Kirkwood. Eaeh approximation makes the heat eapaeity sharper and higher, but still finite. Reprodueed from [6] Nix F C and Shoekley W 1938 Rev. Mod. Phy.s. 10 14, figure 13. Copyright (1938) by the Ameriean Physieal Soeiety.

Fluorine cannot be prepared directly by chemical methods. It is prepared in the laboratory and on an industrial scale by electrolysis. Two methods are employed (a) using fused potassium hydrogen-fluoride, KHFj, ill a cell heated electrically to 520-570 K or (b) using fused electrolyte, of composition KF HF = 1 2, in a cell at 340-370 K which can be electrically or steam heated. Moissan, who first isolated fluorine in 1886, used a method very similar to (b) and it is this process which is commonly used in the laboratory and on an industrial scale today. There have been many cell designs but the cell is usually made from steel, or a copper-nickel alloy ( Monel metal). Steel or copper cathodes and specially made amorphous carbon anodes (to minimise attack by fluorine) are used. Hydrogen is formed at the cathode and fluorine at the anode, and the hydrogen fluoride content of the fused electrolyte is maintained by passing in... 

Cobalt is a bluish silvery metal, exhibits ferromagnetism, and can exist in more than one crystal form it is used in alloys for special purposes. Chemically it is somewhat similar to iron when heated in air it gives the oxides C03O4 and CoO, but it is less readily attacked by dilute acids. With halogens, the cobalt(II) halides are formed, except that with fluorine the (III) fluoride, C0F3, is obtained. 

Nickel is a moderately lustrous, silvery metal, and is extensively used in alloys (for example coinage, stainless steel) and for plating where a durable resistant surface is required. It is also used as an industrial catalyst, for example in the hydrogenation of unsaturated organic compounds. It is attacked by dilute aqueous acids but not by alkalis it combines readily with many non-metals on heating. 

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