Cobalt corrosion-resistant alloy

Various newer and more corrosion-resistant alloys are now available for use, including low nickel alloys, such as Inconel 800 (35% Ni, 20% Cr, 45% Fe). Low nickel alloys, in particular those with with less than 0.03% cobalt, are required to limit the development of a cobalt-induced, outer-core radiation field within the SG. 

Cobalt aluminum blue, transparent, 19 412 CobaltCII) aminobenzoate, uses, 7 239t CobaltCII) ammonium sulfate, uses, 7 239t CobaltCII) arsenate, uses, 7 241t Cobalt-base corrosion-resistant alloys,... 

Cobalt (4 X 10 % of the earth s crust) occurs principally as smaltite, C0AS2, and cobaltite, CoAsS. The metal is used in corrosion-resistant alloys and magnets. Smelting involves oxidation of the ore to C03O4, iron and arsenic being removed as slag, followed by alumino-thermic reduction of the cobalt oxide ... 

Ultimet [Haynes Int L] Cobalt-ba alloy corrosion resistant alloy for nozzles, punq> and valve parts, agitators, ixdts, fan blades, screw conveyors, filters, and rolls. 

The original conductor materials were stainless steel or platinum. These materials were later replaced with more corrosion-resistant alloys with improved fatigue resistance such as MP35N (SPS Technologies Cleveland OH), an alloy of nickel, chromium, cobalt, and molybdenum. In order to further reduce the resistance to current flow, specialized conductors were designed, including DBS (drawn brazed strand) and DFT (drawn filled tube)... 

The Fe, Co, and Ni deposits are extremely fine grained at high current density and pH. Electroless nickel, cobalt, and nickel—cobalt alloy plating from fluoroborate-containing baths yields a deposit of superior corrosion resistance, low stress, and excellent hardenabiUty (114). Lead is plated alone or ia combination with tin, iadium, and antimony (115). Sound iasulators are made as lead—plastic laminates by electrolyticaHy coating Pb from a fluoroborate bath to 0.5 mm on a copper-coated nylon or polypropylene film (116) (see Insulation, acoustic). Steel plates can be simultaneously electrocoated with lead and poly(tetrafluoroethylene) (117). Solder is plated ia solutioas containing Pb(Bp4)2 and Sn(Bp4)2 thus the lustrous solder-plated object is coated with a Pb—Sn alloy (118). 

Titanium alloy systems have been extensively studied. A single company evaluated over 3000 compositions in eight years (Rem-Cm sponsored work at BatteUe Memorial Institute). AHoy development has been aimed at elevated-temperature aerospace appHcations, strength for stmctural appHcations, biocompatibiHty, and corrosion resistance. The original effort has been in aerospace appHcations to replace nickel- and cobalt-base alloys in the 250—600°C range. The useful strength and corrosion-resistance temperature limit is ca 550°C. 

Nonferrous alloys account for only about 2 wt % of the total chromium used ia the United States. Nonetheless, some of these appHcations are unique and constitute a vital role for chromium. Eor example, ia high temperature materials, chromium ia amounts of 15—30 wt % confers corrosion and oxidation resistance on the nickel-base and cobalt-base superaHoys used ia jet engines the familiar electrical resistance heating elements are made of Ni-Cr alloy and a variety of Ee-Ni and Ni-based alloys used ia a diverse array of appHcations, especially for nuclear reactors, depend on chromium for oxidation and corrosion resistance. Evaporated, amorphous, thin-film resistors based on Ni-Cr with A1 additions have the advantageous property of a near-2ero temperature coefficient of resistance (58). 

Cobalt—Chromium Alloys. Co—Cr and Ni—Cr alloys are used predominately for the casting of removable partial dentures fixed partial dentures (bridges), crowns, and inlays are also cast. Because of high hardness, corrosion resistance, and wear resistance cobalt-chromium alloys are used for bite adjustments and as serrated inserts in plastic teeth used in fliU dentures. These alloys are well tolerated by the body and also are used for dental implants and orthopedic implant alloys. 

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