Salts magnesium alloys

Magnesium. This molten salt electrolysis process is the current principal method of magnesium production. The graphite anodes can be either round or rectangular in nature (see Magnesiumand magnesium alloys). 

In considering the corrosion of magnesium and its alloys it is important to examine the methods available for assessing corrosion tendencies and particularly those known as accelerated tests. Tests carried out by immersion in salt water or by spraying specimens regularly with sea-water are worthless as a means of determining the resistance of magnesium alloys under any other than the particular test conditions. Extrapolation to less corrosive conditions is not valid and even the assessment of the value of protective measures by such means is hardly possible. The reason is to be found in the fact that corrosion behaviour is directly related to the formation of insoluble... 

By the use of many commercial abrasive processes, the corrosion resistance of magnesium alloys can be reduced to such an extent that samples of metal that may lie quiescent in salt water for many hours will, after shot blasting, evolve hydrogen vigorously, and the corrosion rate, as measured by loss of weight, will be found to have increased many hundred-fold. The effect in normal atmospheres is naturally much less, yet the activation of the surface is an added hazard and is the opposite of passivation which is essential if later-applied paint finishes are to have proper durability. 

Post-Treatments. Although many post-treatments have been used over plated metals, chromate conversion coatings remain as the most popular. Chromates are used to improve corrosion resistance, provide good paint and adhesive base properties, or to produce brighter or colored finishes. Formulations are usually proprietary, and variations are marketed for use on zinc, zinc alloys, cadmium, copper and copper alloys, and silver (157). Chromates are also used on aluminum and magnesium alloys (158,159). More recently, chromate passivation has been used to extend salt spray resistance of autocatalytic nickel plated parts. 

Filiform corrosion of AZ 91 magnesium alloy has been studied in detail and the mechanism different from the conventional mechanism has been postulated. In this case dissolved oxygen is not necessary and the filiform propagation is fueled by hydrogen evolution at the filament head and is controlled by mass transfer due to the salt film on the tip of the filament.32,33... 

Uranium, plutonium, and the remaining FP-3 elements are separated from the FP-4 elements and the donor alloy by a second salt transport process using a MgCl2-MgF2 salt. The Cu-Mg reduction alloy is the donor alloy. A zinc-magnesium alloy is the acceptor alloy. 

As a consequence of experimental runs and changes in process salt mixtures, a variety of waste salts and alloys have been produced, and much of this material is in storage. These waste products contain varying quantities of magnesium, sodium, potassium, calcium, and aluminum as well as plutonium and americiurn. 

Use Neodymium salts, electronics, alloys, colored glass, (especially in astronomical lenses and lasers), to increase heat resistance of magnesium, metallurgical research, yttrium-garnet laser dope, gas scavenger in iron and steel manufacture. 

NITRIC ACID, BARIUM SALT (10022-31-8) A strong oxidizer. Incompatible with reducing agents, combustibles, strong acids, other oxidizers. Mixtures with sulfur, finely divided metals (especially aluminum and magnesium alloys) can form shock- and friction-sensitive compounds. Contact with ammonium nitrate may cause spontaneous fire or explosions. 

Salt re-melting Re-melting of Mg scrap under a salt cover. Is applicable to the processing of all scrap classes except used fluxes and sludge (not treated). If only class 1 - 2 scrap is used, HP (high purity) magnesium alloys may be produced. 

C.5.1 Magnesium and Magnesium Alloys 150 g chromium tiioxide (CrOj) 10 g silver chromate (Ag2Cr04) Reagent water to make 1000 mL 1 min Boiling The silver salt is present to precipitate chloride. 

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