wire and heat

[domnic]

If i heat a wire just below its melting point and let it cool will this affect the wire as a conductor in any way?

 

[stickboy1375]

Bending PVC with a torch and the wire already installed? :grin:

 

[SEO]

What are you heating the insulation or the bare part of the conductor? Either way you have vastly exceeded the conductor rating and heated section should be replaced.

 

[domnic]

Copper

Copper

If You Heat Copper And Let It Cool Will It Change The Specific Resistance?

 

[mdshunk]

If You Heat Copper And Let It Cool Will It Change The Specific Resistance?

Permanently? No. The resistance will vary with temp, however.

 

[gar]

080923-1908 EST

domnic:

Partly it will depend upon any shape change or accumulation of impurities.

If the copper was hard, heated and even melted, and reformed into its original shape and annealed, then there would be a reisitance difference. See the first reference below of a comparison of soft and hard resistivity. The second reference is also of general reference.

http://www.dossert.com/technicalinfo/barecopperwire.htm

http://www.stormcopper.com/design/Copper-Conductor-Physical-Electrical-Properties.htm

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[LarryFine]

If You Heat Copper And Let It Cool Will It Change The Specific Resistance?

It depends on how oy define "heat." Annealing metal causes permanent changes. One effect is loss of springiness and increase brittleness.

That's why current cycling causes back-stabbed terminations to fail. The heat causes spring weakness, which increases heat, etc.

 

[gar]

080923-2110 EST

Larry:

Generally as you harden a material it becomes less ductal. As you mechanically work copper it work hardens. When it gets too hard it becomes brittle. Then it has to be annealed to soften the material. The process of making wire causes it harden and at various stages has to be annealed to allow further drawing. There are apparently continuous annealing wire drawing processes.

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