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The Effects of Cold Temperatures on Copper Sheets

A reddish-orange metal in its natural state, copper is a member of the periodic table's transitional metals, known for a variety of different properties. Copper is often manufactured into sheets for use in many types of applications, including crafts and roofing, as well as electrical and electronic applications. Copper sheeting's use depends on its thickness, which ranges from .001, to .0216-inches thick. According to Basic Copper, thick copper sheeting is commonly used for roofing, and is often called "roofing copper," or "roofing Flashing." Like any metal, temperature affects copper, but not normally in a detrimental fashion, as with some metals.

Copper Properties
- Copper, the 29th element of the periodic table, was first mined by the ancients as early as 10,000 years ago, with a copper pendant discovered in northern Iraq dating from 8700 B.C., according to Advameg. Although rarely found in pure form, copper is normally part of various ores when in its natural state. Copper is widely used in electrical and plumbing applications because of its conductive and heat transferring capabilities.
Copper Processing
- Copper's manufacturing process consists of five steps: mining, concentrating, smelting, refining and casting. Copper is often mined in large open pits, using blasting and drilling techniques to expose the ore containing copper. Concentrating is the method of separating the waste product from the ore, while smelting and refining removes iron and sulfur, isolating the pure copper. Casting is when copper is melted and cast into a variety of forms, including ingots and rods. Sheeting occurs when casted copper is rolled flat into sheets of various thicknesses.
Effect of Heat on Copper
- According to Bob Wilson and Burr Zimmerman of the Argonne National Laboratory, when copper is heated until glowing red, then cooled, a process known as annealing, it becomes softer and more malleable, due to the growing of metal crystals into each other. Also, heating copper with a butane torch causes it to expand slightly and reduces its thermal conductivity.
Effect of Cold on Copper
- According to the application data sheet, "Mechanical Properties of Copper and Copper Alloys at Low Temperatures," "Copper alloys become stronger and more ductile as temperature goes down. They also retain excellent impact resistance to 20 K. These general characteristics have been revealed in tests on 15 copper alloys, including brasses, bronzes and commercially pure coppers." Likewise, since copper heated with a butane torch causes slight expansion and loss of thermal conductivity, copper contracts and its thermal conductivity improves slightly in cold temperatures. The overall effect of cold temperatures on copper sheets depends on the alloy and amount of copper contained within.

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