Anodes, aluminum nickel

Some firearms are plated with anodized aluminum, nickel, or chromium which gives durability and good looks, and some are made from stainless steel which is much less prone to rust than conventional steel. Electroless nickel coating is an alloy coating of 88% to 96% nickel and 4% to 12% phosphorus, which is produced by chemical (not electrical) reduction of nickel on to the metal surface. 

Nickel acetate tetrahydrate [6018-89-9] Ni(C2H202) 4H2O, is a green powder which has an acetic acid odor, density 1.74 g/cm. When heated, it loses its water of crystallization and then decomposes to form nickel oxide. Nickel acetate is used as a catalyst intermediate, as an intermediate in the formation of other nickel compounds, as a dye mordant, as a sealer for anodized aluminum, and in nickel electroplating (59). 

Nickel acetate is used as a catalyst. It also is used as a dye mordant in textiles. Other applications are in electroplating nickel and as a sealer for anodizing aluminum. 

Metal Coatings. Tellurium chlorides, as well as tellurium dioxide in hydrochloric acid solution, impart permanent and attractive black antique finish to silverware, aluminum, and brass. Anodized aluminum is colored dark gold by tellurium electro deposition. A solution containing sodium tellurate and copper ions forms a black or blue-black coating on ferrous and nonferrous metals and alloys. Addition of sodium tellurite improves the corrosion resistance of electroplated nickel. Tellurium diethyldithiocarbamate is an additive in bright copper electroplating (see Electroplating). 

In any event, practical solutions to the problem were found. The simplest solution is to coat the surfaces of polymeric composites and other sensitive surfaces with thin films of materials that resist corrosion. Among the coatings that appear to provide protection are anodized aluminum and thin layers of sputtered nickel. 

Nickel compounds are of great importance industrially and a review is available on the use of nickel in heterogeneous catalysis, electroplating, batteries, pigments, ceramics and hydrogen storage.76 This concerns simple aqua complexes of nickel(II) with anions such as carbonate, halide, hydroxide, nitrate and sulfate. Nickel acetate and formate find similar use, and the acetate is employed in the sealing of anodized aluminum.77 [Ni(NH3)6]Cl2 has been shown to be potentially applicable in heat pumps.78... 

The previous paragraph assumes that the ethanol will be dry (containing no water) and contain only very small amounts of contaminants such as chloride and sulfate ions that would greatly increase the corrosivity of ethanol. Ethanol produced for fuel purposes in the past has contained up to 5 volume percent water and ion concentrations that made it much more corrosive than pure ethanol [3.7]. For an ethanol fuel with these corrosion characteristics, it was found that aluminum and steel could be coated with cadmium, hard chromium, nickel, or anodized aluminum to make them compatible. Coatings such as zinc, lead, and phosphate were found to be inadequate to prevent corrosion [3.7]. 

The efficient preparation of trimethyl(trinuoroinethyl)silane via the eleetroredaction of bromo-trifluoroniethane in dimethylformamide in the presence of chlorotrimethylsilane using a sacrificial aluminum anode and nickel foam cathode (area 20 cm ) containing tetrabutylam-... 

A passive metal is one that is active in the Emf Series, but that corrodes nevertheless at a very low rate. Passivity is the property underlying the useful natural corrosion resistance of many structural metals, including aluminum, nickel, and the stainless steels. Some metals and alloys can be made passive by exposure to passivating environments (e.g., iron in chromate or nitrite solutions) or by anodic polarization at sufficiently high current densities (e.g., iron in H2SO4). 

The anodes consist mainly of a mixture of the Raney nickel catalyst, copper powder, and PTFE powder on a copper grid as described by Riihling [50]. The Raney nickel catalyst is composed of highly porous metal particles and is formed from an aluminum-nickel alloy by dissolving the aluminum. The advantages of using the Raney material are described above. 

The relatively low abrasion and wear resistance of aluminum can be compensated by an appropriate surface treatment so that sufficient life times can be achieved. Hard anodizing, chemical nickel plating, chrome plating, and special chemical coatings, which facilitate demolding, have proven their worth. 

They have good corrosion resistance. Therefore, one can do without expensive surface treatments. However, it is possihie to chrome plate, nickel plate, or hard anodize aluminum plates after machining (electrical discharge machining [EDM]). 

Further improvements in anode performance have been achieved through the inclusion of certain metal salts in the electrolyte, and more recently by dkect incorporation into the anode (92,96,97). Good anode performance has been shown to depend on the formation of carbon—fluorine intercalation compounds at the electrode surface (98). These intercalation compounds resist further oxidation by fluorine to form (CF ), have good electrical conductivity, and are wet by the electrolyte. The presence of certain metals enhance the formation of the intercalation compounds. Lithium, aluminum, or nickel fluoride appear to be the best salts for this purpose (92,98). 

The cathodic protection of plain carbon and low-alloy steels can be achieved with galvanic anodes of zinc, aluminum or magnesium. For materials with relatively more positive protection potentials (e.g., stainless steels, copper, nickel or tin alloys), galvanic anodes of iron or of activated lead can be used. 

Electrorefining has been used for the purification of many common as well as reactive metals. It has been seen that the emf or the potential required for such a process is usually small because the energy needed for the reduction of the ionic species at the cathode is almost equal to that released by the oxidation of the crude metal at the anode. Some metals, such as copper, nickel, lead, silver, gold, etc., are refined by using aqueous electrolytes whereas molten salt electrolytes are necessary for the refining of reactive metals such as aluminum,... 

Other materials such as gold (< = 4.9 eV), aluminum (< = 4.2 eV), indium-doped zinc oxide, magnesium indium oxide, nickel tungsten oxide, or other transparent conductive oxide materials, have been studied as anodes in OLEDs. Furthermore, the WF of ITO can be varied by surface treatments such as application of a very thin layer of Au, Pt, Pd, or C, acid or base treatments, self-assembly of active surface molecules, or plasma treatment. 

A very early use of anodic alumina as a template involved colonization of the alumina by depositing nanometals in the pores [39]. Somewhat later, Kawai and Ueda templated cobalt and nickel in alumina by electrodeposition [40]. Other metals were deposited by Andersson et al. [41] and Patel et al. [42]. The use of anodic alumina as a template increased after Furneaux et al. developed a convenient voltage-reduction method for detaching the porous anodized alumina from the underlying aluminum [38]. 

Molten Carbonate Fuel Cell The electrolyte in the MCFC is a mixture of lithium/potassium or lithium/sodium carbonates, retained in a ceramic matrix of lithium aluminate. The carbonate salts melt at about 773 K (932°F), allowing the cell to be operated in the 873 to 973 K (1112 to 1292°F) range. Platinum is no longer needed as an electrocatalyst because the reactions are fast at these temperatures. The anode in MCFCs is porous nickel metal with a few percent of chromium or aluminum to improve the mechanical properties. The cathode material is hthium-doped nickel oxide. 

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