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Re: [Phys-L] aluminum resistivity

On 07/21/2014 09:22 AM, Folkerts, Timothy J wrote:
The wires are almost certainly an alloy, so the resistivity will
probably be noticeably larger than pure Al. Apparently "1350-h19" is
a common alloy for wires,


Note that's still 99.5% Al.

and you can find a resistivity of 28.2 uOhm-cm


That's about 6% more than the accepted value for ultra-pure Al.

That alloy is carefully designed to make a tradeoff between
mechanical strength and conductivity. This stands in contrast
to alloys designed for mechanical strength alone, which have
really terrible conductivity.

Although the conductivity of the commonly used conducting
alloy (1350) is only around 62% of annealed copper, it is
only one third the weight and can therefore conduct twice
as much electricity when compared with copper of the same
That's a quote from


Note that for some applications, it pays to use cable with
high-strength strands in the middle and high-conductivity
strands on the outside:


We can do some fun physics with this:

Note that the resistivity of pure Al is due to scattering
by thermal phonons.

The resistivity of the alloy includes the aforementioned
thermal phonon scattering, plus a smallish amount of
impurity scattering.

The phonon contribution is linear in temperature at high
enough (non-cryogenic) temperatures. So from winter to
summer you can see a 10% variation in this contribution.

So ... the temperature correction term is on the same order
of magnitude as the alloy correction term.