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smelting

(Encyclopedia)smelting, in metallurgy, any process of melting or fusion, especially to extract a metal from its ore. Smelting processes vary in detail depending on the nature of the ore and the metal involved, but ...

cloisonné

(Encyclopedia)cloisonné kloizənāˈ, –sənāˈ [key], method of enamel decoration of metal surfaces, such as vases and jewel boxes. Metal filaments (which form the cloisons or separating elements) are attached ...

hafnium

(Encyclopedia)hafnium hăfˈnēəm [key], metallic chemical element; symbol Hf; at. no. 72; at. wt. 178.49; m.p. about 2,227℃; b.p. 4,602℃; sp. gr. 13.31 at 20℃; valence +4. Hafnium is a lustrous, ductile, si...

yttrium

(Encyclopedia)yttrium ĭtˈrēəm [key] [for Ytterby, a town in Sweden], metallic chemical element; symbol Y; at. no. 39; at. wt. 88.90585; m.p. about 1,522℃; b.p. 3,338℃; sp. gr. about 4.45; valence +3. Yttriu...

refining

(Encyclopedia)refining, any of various processes for separating impurities from crude or semifinished materials. It includes the finer processes of metallurgy, the fractional distillation of petroleum into its comm...

neodymium

(Encyclopedia)neodymium nēˌōdĭmˈēəm [key], metallic chemical element; symbol Nd; at. no. 60; at. wt. 144.242; m.p. about 1,021℃; b.p. about 3,068℃; sp. gr. 7.004 at 20℃; valence +3. Neodymium is a lust...

cerium

(Encyclopedia)cerium sērˈēəm [key] [from the asteroid Ceres], metallic chemical element; symbol Ce; at. no. 58; at. wt. 140.116; m.p. 799℃; b.p. 3,426℃; sp. gr. 6.77 at 25℃; valence +3 or +4. Cerium is a ...

die-casting

(Encyclopedia)die-casting, process by which molten metal is forced by a plunger or compressed air into a metallic die and the pressure maintained until the metal has solidified. Die castings are accurate, are sharp...

chloride

(Encyclopedia)chloride klōrˈīd, klôrˈ– [key], chemical compound containing chlorine. Most chlorides are salts that are formed either by direct union of chlorine with a metal or by reaction of hydrochloric ac...

ductility

(Encyclopedia)ductility, ability of a metal to plastically deform without breaking or fracturing, with the cohesion between the molecules remaining sufficient to hold them together (see adhesion and cohesion). Duct...