Nickel alloy powders

Wax, Hydrocarbon (For Ordnance Use) Zinc Dust (For Use in Pyrotechnics) Zinc Oxide, Technical Zirconium (Granular and Powdered) Zirconium-Nickel Alloy, Powdered... 

Zhelibo EP, Kravets NN (1997) Theory, preparation technology, and properties of powders and fibers. Influence of the electrolysis temperature on the formation, composition, and magnetic properties of highly dispersed Iron and Iron-Nickel alloy powders. Powd Metall Metal Ceram 36 264-268... 

In atomization, a stream of molten metal is stmck with air or water jets. The particles formed are collected, sieved, and aimealed. This is the most common commercial method in use for all powders. Reduction of iron oxides or other compounds in soHd or gaseous media gives sponge iron or hydrogen-reduced mill scale. Decomposition of Hquid or gaseous metal carbonyls (qv) (iron or nickel) yields a fine powder (see Nickel and nickel alloys). Electrolytic deposition from molten salts or solutions either gives powder direcdy, or an adherent mass that has to be mechanically comminuted. 

Nickel [7440-02-0] Ni, recognized as an element as early as 1754 (1), was not isolated until 1820 (2). It was mined from arsenic sulfide mineral deposits (3) and first used in an alloy called German Silver (4). Soon after, nickel was used as an anode in solutions of nickel sulfate [7786-81 A] NiSO, and nickel chloride [7718-54-9] NiCl, to electroplate jewelry. Nickel carbonyl [13463-39-3] Ni(C02)4, was discovered in 1890 (see Carbonyls). This material, distilled as a hquid, decomposes into carbon monoxide and pure nickel powder, a method used in nickel refining (5) (see Nickel and nickel alloys). 

Nickel sulfide, NiS, can be prepared by the fusion of nickel powder with molten sulfur or by precipitation usiag hydrogen sulfide treatment of a buffered solution of a nickel(II) salt. The behavior of nickel sulfides ia the pure state and ia mixtures with other sulfides is of iaterest ia the recovery of nickel from ores, ia the high temperature sulfide corrosion of nickel alloys, and ia the behavior of nickel-containing catalysts. 

Metallic cobalt, metallic nickel and an alloy powder containing 66-67% nickel, 13-16% chromium and 7% iron... 

The product is hydrogenated in 4,000 cc of ethanol at room temperature and under normal atmospheric pressure with a catalyst prepared In the usual manner from 400 g of Raney nickel alloy. The calculated amount of hydrogen is taken up in approximately 75 hours. After filtration and evaporation to a small volume, the residue Is distributed between 1,000 cc of chloroform and water each. The chloroform solution is then dried over sodium sulfate and evaporated to a small volume. Precipitation of the hydrogenation product with petroleum ether yields an amorphous white powder which Is filtered by suction, washed with petroleum ether and dried at 50°C In a high vacuum. 1. athyl-2-podophyllinic acid hydrazide is obtained in a practically quantitative yield. 

The desire to replace cadmium is generally attributed to its toxicity, both in terms of process pollution and product corrosion, and several alternatives are feasible thicker zinc, tin-zinc alloy or tin-nickel alloy depending upon the precise application " . The demise of decorative nickel-chrome systems in the automotive industries of the world is partly due to cost and partly to market image, and not to technical performance where major improvements took place in the period 1960-1975 through the establishment of duplex nickel under-layers and micro discontinuous chromium top-layers. In the 1980s the trend has been towards black finishes produced generally by powder-applied epoxy polymers. 

Copper and nickel alloys Dip for 1-3 min in 1 1 HCl or 1 10 HjSOj at room temperature. Scrub lightly with bristle brush under running water, using fine scouring powder if needed. 

Significant improvement of tantalum powder properties was achieved by the application of molten alkali halides as solvents for potassium heptafluorotantalate, K2TaF7. Variation of the initial concentration of K2TaF7 in the melt, stirring and rate of sodium loading enable a well-controllable production of tantalum powder with a wide variety of specific charges. Heller and Martin [590] proposed the use of a reactor equipped with a stirrer in 1960. Fig. 142 shows a typical scheme of the reactor [24, 576]. All metal parts of the reactor are made of nickel or nickel alloy. 

This process uses a moving laser beam, directed by a computer, to prepare the model. The model is made up of layers having thicknesses about 0.005-0.020 in. (0.012-0.50 mm) that are polymerized into a solid product. Advanced techniques also provides fast manufacturing of precision molds (152). An example is the MIT three-dimensional printing (3DP) in which a 3-D metal mold (die, etc.) is created layer by layer using powdered metal (300- or 400-series stainless steel, tool steel, bronze, nickel alloys, titanium, etc.). Each layer is inkjet-printed with a plastic binder. The print head generates and deposits micron-sized droplets of a proprietary water-based plastic that binds the powder together. 

Nickel sulfate can be produced from either pure or impure sources. The pure source involves the reaction of pure nickel or nickel oxide powder (combined or separately) with sulfuric acid to produce nickel sulfate that is filtered and crystallized to produce a solid product. The impure raw material may be spent industrial liquor that contains a high percentage of nickel sulfate. The impurities in the liquor are precipitated by sequential treatment with oxidizers lime and sulfides can later be filtered out. The treated liquor, which is a pure solution of nickel sulfate, can be packaged in a drum or further crystallized and dried to produce solid nickel sulfate. Nickel sulfate is used mainly in the metal plating industries. Other uses include dyeing and printing of fabrics and production of patina, an alloy of zinc and brass. 

Hydrogen absorption/desorption characteristics of magnesium-nickel alloy containing 23 atomic% Ni. (Reproduced with permission from Schwarz, R.B., Storage of hydrogen in powders with nanosized crystalline domains, Mater. Res. Bull., 24, 40, 1999, available at http //www.wtec.org/loyola/nano/US.Review/04 06.htm, May 2007.)... 

This is an on-going project aimed at examining the T/D characteristics of metals and alloys in a marine medium in seven- and twenty eight-day tests. The data obtained to date on seven-day tests of cuprous oxide (Cu20) and nickel metal powder (Ni) provides useful comparisons with those reported earlier for the freshwater OECD 203-based media at pH 6 and 8 (Skeaff Hardy 2005) and insight into the behaviour of metal-bearing substances used in commerce under marine conditions of the T/DP. The data supports an approach directed to the eventual adaptation, validation and application of the OECD T/DP to marine systems for the purposes of marine hazard classification of metals, metal compounds and alloys. 

Co-reduction of mixed oxides. A two-stage preparation of an alloy through the synthesis of a suitable precursor may be exemplified by the chemical route used by Jena et al. (2004) in the preparation of a copper-nickel alloy. The alloy was prepared from an aqueous solution of the nitrates of copper and nickel dissolved in a minimum amount of water and allowed to dehydrate and decompose to their oxides at a temperature around 350°C for an hour. Samples of the mixed oxide powders thus formed were subjected to reduction by pure hydrogen. The reduced powder (apparently containing partially alloyed metals) was sintered at 1000°C. The effect of temperature (250-450°C) on the reduction of the co-formed oxides was studied. 

Mkaline Fuel Cell The electrolyte for NASA s space shnttle orbiter fuel cell is 35 percent potassinm hydroxide. The cell operates between 353 and 363 K (176 and I94°F) at 0.4 MPa (59 psia) on hydrogen and oxygen. The electrodes contain platinnm-palladinm and platinum-gold alloy powder catalysts bonded with polytetraflnoro-ethylene (PTFE) latex and snpported on gold-plated nickel screens for cnrrent collection and gas distribution. A variety of materials, inclnding asbestos and potassinm titanate, are used to form a micro-porous separator that retains the electrolyte between the electrodes. The cell structural materials, bipolar plates, and external housing are nsnally nickel-plated to resist corrosion. The complete orbiter fuel cell power plant is shown in Fig. 24-48. 

D. J. Zouder et al, "Development of Zirconium-Nickel Alloy Delay Powder for M204A1 Hand Grenade Fuzes , PATR 2228 (Jan 1956)... 

Method No 308. Delay Powder, Non-Gaseous (Zirconium-Nickel Alloy Type) Type I (delay 2-sec) - Ba chromate 60.0, 70/30 Zr-Ni alloy 26.0 8t K perchlorate 14.0% ... 

Powder Formation. Metallic powders can be formed by any number of techniques, including the reduction of corresponding oxides and salts, the thermal dissociation of metal compounds, electrolysis, atomization, gas-phase synthesis or decomposition, or mechanical attrition. The atomization method is the one most commonly used, because it can produce powders from alloys as well as from pure metals. In the atomization process, a molten metal is forced through an orifice and the stream is broken up with a jet of water or gas. The molten metal forms droplets to minimize the surface area, which solidify very rapidly. Currently, iron-nickel-molybdenum alloys, stainless steels, tool steels, nickel alloys, titanium alloys, and aluminum alloys, as well as many pure metals, are manufactured by atomization processes. 

The fuels are finely powdered metals (2.0-10.0 g) among which titanium, zirconium, manganese, tungsten, molybdenum and antimony are very common. Sometimes, non-metal powders such as boron and silicon (for fast burning delays), binary alloy powders such as ferrosilicon, zirconium-nickel, aluminum-palladium and metal compounds such as antimony sulfide, calcium silicide etc. are also used. 

To promote the activity and selectivity of Raney nickel catalysts, alloying of the starting Ni-Al alloy with metal was often used. For instance, Montgomery (ref. 4) prepared catalysts by activating ternary alloy powders of Al (58 wt %)-Ni (37-42 wt %) - M (0.5 wt %) where M = Co, Cr, Cu, Fe and Mo. All promoted catalysts tested were more active than the reference catalyst, in hydrogenation of butyronitrile. Molybdenum was the most effective promoter. With Cr or Ti, hydrogenation of isophtalonitrile on Raney nickel occurred at lower optimum temperature than with non activated nickel (ref. 5). It was shown that addition of Ti or Co to Raney nickel suppressed the formation of secondary amine (ref. 6). 

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