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Chapter 18. Copper. Copper Manufacturing • Copper Alloys • Copper Fabrication • Copper Alloy Properties. Copper is extracted chiefly from sulfide ores and processed into specific finished forms.
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Chapter 18 Copper Copper Manufacturing • Copper Alloys • Copper Fabrication • Copper Alloy Properties
Copper is extracted chiefly from sulfide ores and processed into specific finished forms.
To a large extent, the foundry properties of copper alloys depend on whether they are low-shrinkage or high-shrinkage alloys.
Annealing heat treatments are used to homogenize, soften, or stress relieve copper alloys.
Copper alloys are designated in the Unified Numbering System (UNS) for metals and alloys.
Temper designations indicate mechanical working and heat treatment conditions of copper alloys.
Each system exhibits different properties that are characteristic of that system.
The microstructure of tough pitch copper heated in hydrogen for 2 min. at 850°C (1560°F) shows black voids, which correspond to porosity created by pockets of water vapor (steam).
Aging develops (CuCo)Be berylideinclusions in the copper-rich matrix of beryllium coppers.
Low-beryllium coppers and high-beryllium coppers are the two groups of beryllium coppers.
The selected aging temperature for beryllium coppers depends on the desired properties and the amount of prior cold work.
The microstructure of leaded beta brass shows a dispersion of lead particles.
The copper end of the copper-tin phase diagram shows a wide temperature range between the liquidusand the solidus, making these alloys highly susceptible to coring.
The copper end of the copper-aluminum phase diagram indicates that alloys up to approximately 8% Al are single phase.
The microstructure of cast duplex aluminum bronzes may be altered by the rate of cooling.
The microstructure of nickel-aluminum bronzes shows kappa phase and iron rounds.
The copper-silicon phase diagram indicates that alloys with up to 5% Si are single phase because the eutectoid reaction is very sluggish.
The copper-nickel phase diagram indicates that copper and nickel are soluble in one another at all compositions and form a single-phase microstructure.
Grain size is the major property that determines drawability and stretching formability of coppers and single-phase copper alloys.
Welding filler metals used for welding copper and copper alloys may be covered electrodes or bare wire.
Silver alloy and copper-phosphorus filler metals are commonly used to braze copper alloys.
Cast copper alloys may be divided into three groups according to ease of machining.