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hardening

(Encyclopedia)hardening, in metallurgy, treatment of metals to increase their resistance to penetration. A metal is harder when it has small grains, which result when the metal is cooled rapidly. Sometimes small ar...

sintering

(Encyclopedia)sintering, process of forming objects from a metal powder by heating the powder at a temperature below its melting point. In the production of small metal objects it is often not practical to cast the...

electrophorus

(Encyclopedia)electrophorus, device used to generate static electric charges. It has two parts: a nonconducting plate (e.g., of hard rubber) that is negatively charged and a metal plate with an insulated handle. A ...

carbide

(Encyclopedia)carbide, any one of a group of compounds that contain carbon and one other element that is either a metal, boron, or silicon. Generally, a carbide is prepared by heating a metal, metal oxide, or metal...

organometallic chemistry

(Encyclopedia)organometallic chemistry, the reactions and use of a class of compounds (R-M) that contain a covalent bond between carbon and metal. They are prepared either by direct reaction of the metal with an or...

gadolinium

(Encyclopedia)gadolinium gădəlĭnˈēəm [key], metallic chemical element; symbol Gd; at. no. 64; at. wt. 157.25; m.p. 1,312℃; b.p. 3,233℃; sp. gr. 7.898 at 25℃; valence +3. Gadolinium is a malleable, ducti...

plating

(Encyclopedia)plating, application of a plate, or coat, of metal to a surface for decoration, reflection of light, protection against corrosion, or increased wearing quality. The practice is of ancient origin: gild...

Beaver Dam

(Encyclopedia)Beaver Dam, city (2020 pop. 16,708), Dodge co., SE Wis., on Beaver Dam Lake, in a productive farm and dairy area; inc. 1856. Industries included food pr...

forging

(Encyclopedia)forging, shaping metal by heating it and then hammering or rolling it. Forging is the method by which metal was first worked when it came into use about 4000 b.c. in Egypt and Asia. Modern forging is ...

zirconium

(Encyclopedia)zirconium zərkōˈnēəm [key], metallic chemical element; symbol Zr; at. no. 40; at. wt. 91.224; m.p. about 1,852℃; b.p. 4,377℃; sp. gr. 6.5 at 20℃; valence +2, +3, or +4. Zirconium is a very ...