Melting technique

FEP plastics Copolymers of tetrafluoro-ethene and hexafluoropropene. Inert and corrosion resistant as Teflon but can be processed by melt techniques. 

Eigure 11 illustrates the superior conductivity of P/M silver—nickel or silver—cadmium oxide contacts when compared with contacts made by standard melting techniques and formed from soHd-solution alloys. 

Consolidation. ConsoHdation by the consumable-electrode electric-arc melting technique is ideally suited for vanadium and is used extensively... 

Semiconductor and Solar Cells. High purity (up to 99.9%) antimony has a limited but important appHcation in the manufacture of semiconductor devices (see Semiconductors). It may be obtained by reduction of a chemically purified antimony compound with a high purity gaseous or soHd reductant, or by thermal decomposition of stibine. The reduced metal may be further purified by pyrometaHurgical and zone melting techniques. 

Coumaria has also beea purified by vacuum azeotropic distillatioa with polyhydroxy alcohols such as triethyleae glycol (65). Puriftcatioa by zoae melting techniques has been described ia several pubHcatioas (66—68). 

In addition to the above, purification of /V-methylacetamide can be achieved by fractional freezing, including zone melting, repeated many times, or by chemical treatment with vacuum distn under reduced pressures. For details of zone melting techniques, see Knecht in Recommended Methods for Purification of Solvents and Tests for Impurities, Coetzee Ed. Pergamon Press 1982. 

Elements dissolved in boron influence its crystal structure. Dissolved impurities also influenee the physical and chemical properties of boron, especially the electrical properties, because boron is a semiconductor. Preparation of solid solutions in jS-rh boron requires a careful choice of crucible material. To avoid contamination, boron nitride or a cold, coinage-metal crucible should be used or the levitation or floating-zone melting techniques applied. 

Architectural coatings, 18 55-56 economic aspects of, 18 73-74 Architectural fabrics, 13 394 Architectural paints, 18 72 Archives, preservation of, 11 414 Arch Raschig process flow sheet, 13 578 Arc melting techniques, 25 522-523 ARCO process, 23 342 Arc-resistance furnace, 12 304 Arc resistance testing, 19 587 Arctic polar stratospheric clouds, effect on ozone depletion, 17 789-790 Arc vaporization, 24 738 Arc welding, copper wrought alloys,... 

Consumable-electrode melting, 12 302 Consumable-electrode electric-arc melting technique, 25 522... 

This is all prolog material to the implications of a recent and preliminary experiment recently conducted at Purdue. Using a vacuum e-beam melting technique a solid Al-Ga-In-Sn alloy with a composition of 95 vt% A1 and 5 wt% Ga-In-Sn (95-51 was fabricated. This turns out to be a major breakthrough technologically and economically. 

Binh, V. T., and Garcia, N. (1992). On the electron and metallic ion emission from nanotips fabricated by field-surface-melting technique experiments on W and Au tips. Ultramicroscopy, 42-44, 80-90. 

Cubic Zirconia. As of this writing, cubic zirconia [1314-23-4], Zr02, is the best diamond imitation available (Table 3). It is marketed under such names as CZ, Cerene, Cubic zirconium, Diamonair II, Diamonique III, Fianite, etc, and grown by the skull melting technique (2,5,13). Pure Zr02 is... 

As shown by Fig. 22.16, the concentrations of solute atoms are significantly reduced in the material that is solidified early in the solidification process when k < 1. One-dimensional plane-front solidification can therefore be used as a method of purification. However, purification is carried more effectively out by modifying the process and adopting a zone-melting technique. 

All fluoroplastics except polyietrafluiiruetliylune can be processed using melt techniques commonly applicable to thermoplastics. Processing temperatures are somewhat higher than normally used with other thermoplastics and corrosion-resistant equipment is required to resist the corrosive effects of the molten polymer,... 

The conventional industrial method for the synthesis of a-silicon carbide is to heat silica (sand) with coke in an electric furnace at 2,000-2,500 °C. However, because of the high melting point of the product, it is difficult to fabricate by sintering or melt techniques. Thus, the discovery of a lower temperature fabrication and synthesis route to silicon carbide by Yajima and coworkers in 197526,27 proved to be an important technological breakthrough. This is a preceramic polymer pyrolysis route that has been developed commercially for the production of ceramic fibers. 

Another novel technique of making oxide fibres is called the inviscid melt technique [24], In principle, any material in a molten state can be drawn into a fibre shape. Organic polymeric fibres such as nylon, aramid, etc., as well as a variety of glasses can be routinely converted into fibrous form by passing a molten material, having an appropriate viscosity, through an orifice. The inviscid (meaning low viscosity) melt technique uses this principle to make oxide fibres. 

Dichromium pentafluoride is an idealized formula, since the compound is reported (55) to have a composition in the range CrF2.40-2.45-However, the structure derived using X-ray data, from a single crystal grown by high-temperature melt techniques, is based on the stoichiometric formula, with some vacant anion sites (53). The compound is monoclinic, a = 7.773(5), b = 7.540(5), c = 7.440(5) A, j3 = 124.25(1)°, space group C2/c. 

Figure 1. Uniform, unoriented, quenched HMS specimen made by the capillary vacuum melt technique...

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