conductivity of copper
One of the most important properties of lead-free copper is that it has excellent electrical conductivity, with a conductivity of 58m/(Ω.mm square). This property makes copper widely used in the electronics, electrical, telecommunications and electronics industries. This high electrical conductivity of copper is related to its atomic structure: when multiple individual copper atoms are combined into a copper block, their valence electrons are no longer confined to the copper atoms, so they can move freely in all solid copper. , its conductivity is second only to that of silver. The international standard for the conductivity of copper is that the conductivity of a copper with a length of 1m and a weight of 1g at 20°C is recognized as 100%. The current copper smelting technology has been able to produce the same grade of copper with a conductivity 4% to 5% higher than this international standard.
Thermal conductivity of copper
Another important effect of free electrons in solid copper is that it has extremely high thermal conductivity. Its thermal conductivity is 386W/(m.k), which is second only to silver. In addition, copper is more abundant and cheaper than gold and silver, so it is made into various products such as wires and cables, connector terminals, bus bars, lead frames, etc., which are widely used in the electrical and electronic, telecommunication and electronic industries. Copper is also a key material for various heat exchange equipment such as heat exchangers, condensers, and radiators. It is widely used in power station auxiliary machines, air conditioners, refrigeration, automobile water tanks, solar collector grids, seawater desalination and medicine, chemical industry. , metallurgy and other heat exchange occasions.
Corrosion resistance of copper
Copper has good corrosion resistance, better than ordinary steel, and better than aluminum in alkaline atmosphere. The potential sequence of copper is +0.34V, which is higher than that of hydrogen, so it is a metal with a relatively positive potential. The corrosion rate of copper in fresh water is also very low (about 0.05mm/a). And when copper pipes are used to transport tap water, the walls of the pipes do not deposit minerals, which is far beyond the reach of iron water pipes. Because of this feature, copper water pipes, faucets and related equipment are widely used in advanced bathroom water supply devices. Copper is extremely resistant to atmospheric corrosion, and it can form a protective film mainly composed of basic copper sulfate on the surface, namely patina, and its chemical composition is CuS04*Cu(OH)2 and CuSO4*3Cu(OH)2. Therefore, copper is used for building roof panels, rainwater pipes, upper and lower pipes, and pipe fittings; chemical and pharmaceutical containers, reactors, pulp filters; ship equipment, propellers, life and fire pipe networks; punched coins (corrosion resistance) ), decoration, medals, trophies, sculptures and handicrafts (corrosion resistance and elegant color), etc.
Post time: Jul-04-2022