Materials high-temperature metals

Splash condenser dross residue. The treatment of steel production pollution control sludge generates a zinc-laden residue, called dross. This material, generated from a splash condenser in a high-temperature metal recovery process, is known as a splash condenser dross residue. Because this material contains 50 to 60% zinc, it is often reclaimed, reused, or processed as a valuable recyclable material. Facilities commonly handle this material as a valuable commodity by managing it in a way that is protective of human health and the environment, so U.S. EPA excluded this residue from the definition of solid waste. 

Containerless processing is also of interest in physical metallurgy, as it provides opportunities to study thermophysical properties of high temperature metals and alloys, avoid sample contamination due to contact with container walls, and observe the solidification of materials that have been rapidly cooled from the melt. 

For both nuclear and solar systems, appropriate material selection will be essential. A qualification programme for high temperature metallic materials must demonstrate their good long-term performance. In the nuclear case, candidate materials will be exposed to helium of 1 000°C with impurities such as CO, C02, H2, H20, CH4 and to neutron irradiation. The experience gained so far has disclosed that the technical solution of material problems requires further efforts in the future. 

To emphasize the importance of structural studies at LT or HP, let us take the example of TTF-TCNQ. This prototype charge density wave (CDW) system undergoes at ambient pressure a succession of three structural and electronic phase transitions, from a high-temperature metallic phase down to a low-temperature insulator phase. There has been a considerable debate about the mechanism of these transitions, and many distortional modes have been proposed to account for the physical properties of this material (e.g., rigid molecule displacement as translations [73,74] or librations [75,76] or even internal deformations of the molecules [77,78]. Indeed, an experi-... 

Hildebrand, D. L. and Cublclotl, D. D. eds. Proc. of the Symp. on "High Temperature Metal Halide Chemistry" (The Electrochemical Soc. Inc. Proc. 78-1, Princeton, NJ, 1978). Hastle, J. W. ed. Proc. of the 10th Materials Research Symp. on "Characterization of High Temperature Vapors and Gases" (National Bureau of Standards Special Publication 561, Washington, D.C., 1979). 

The plasma-spraying technology has been best evaluated and most widely utilized for oxide materials but may also serve for application of high - temperature metals, carbides, borides, nitrides, silicides, etc. Of the non-metallic materials employed in plasma spraying at present, leading position has been gained by AI2O3 possibly modified by further oxides. 

To illustrate the effect on Prox performance by changing the substrate from a monolith to an SCT, Figure 7.10 shows the conversion versus selectivity for the exact same Pt/y-Al203 formulation. The SCT reactor was a woven mesh type where a number of interlaced wires are woven together to form a screen. The wire diameters were 0.003 in. and made of Inconel. The monolithic reactor was constructed of 400 cells in. 2 with a foil thickness of 0.003 in. and 0.3-in. thick. The material was made from Hastelloy-X, which is a high-temperature metal alloy. The catalyst formulation was identical on both reactors with a nominal loading per piece of 0.5244 g or 178.1 mg/in. 3. 

Use Additive to tungsten- and molybdenum-based alloys, electronic filaments, electrical contact material, high-temperature thermocouples, igniters for flash bulbs, refractory metal components of missiles, catalyst, plating of metals by electrolysis and vapor-phase deposition. 

INMETCO s High Temperature Metals Recovery process reclaims the nickel, chromium, iron, molybdenum and cobalt fi om the secondary wastes indicated above and produces a remelt alloy in cast pig form, weighing 25-30 pounds. The remelt alloy is shipped to most of the stainless steel manufacturers in the United States, as well as certain other international companies, for use as raw material feedstock in the production of more stainless steel. As an ISO 9002 certified facility, INMETCO, a fully permitted facility, is the only High Temperature Metals Recovery facility in North America dedicated to the recovery of nickel, chromium, iron and molybdenum from both hazardous and non-hazardous wastes. 

The external case of the rocket motor supports the mechanically and thermally induced stresses, which are due to internal gas pressure, vibration, acceleration, thrust vector control, and differential thermal expansion of component materials. To accommodate these factors, the structural material should have high strength, adequate modulus, and resistance to buckling. Either a continuous glass filament wound epoxy plastic or a high temperature metal (steel, titanium, or aluminum) case serves as the exterior structural member. 

J. K. Tien, and M. W. Kopp, Interfacial reactions in high temperature metallic and intermetallic composites a status review, in Metal and Ceramic Matrix, R.B. Bhagat, A.H. Clauer, P. Kumar and A.M. Ritter, eds.. The Minerals, Metals and Materials Society, Warrendale, PA, 443456 (1990). 

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