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Re: Conductivity of metals was: Re: propeller gap help (fwd)



---------- Forwarded message ----------
Date: Thu, 26 Jul 2007 14:29:10 -0700
From: huil888 <huil888@xxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Conductivity of metals was: Re: propeller gap help (fwd)

Jason -

Something just doesn't look right with this conductivity value (113% of
IACS).  All the other sources I have been able to find show TiB2 to have a
resistivity of ~10-30 micro-Ohm-cm, whereas silver and annealed copper have
resistivity values of ~1.6 and 1.72 micro-Ohm-cm.

A spark-gap electrode material with better conductivity than copper or
silver, plus great high-temperature mechanical properties, just sounds too
good to be true .....

Regards,
Scott Hanson
----- Original Message ----- 
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Wednesday, July 25, 2007 6:14 AM
Subject: Re: Conductivity of metals was: Re: propeller gap help (fwd)


>
> ---------- Forwarded message ----------
> Date: Tue, 24 Jul 2007 21:28:16 -0400
> From: Jason Johnson <jasonmsusolar@xxxxxxxxx>
> To: Tesla list <tesla@xxxxxxxxxx>
> Subject: Re: Conductivity of metals was: Re: propeller gap help (fwd)
>
> Bert,
>
> This site is much cooler than I initially realized - thanks for pointing
> out
> the neat calculators and formula pages etc.
>
> As a side note, the table concerning conductivity of misc. materials makes
> me want to build a spark gap utilizing titanium diboribe electrodes. TiB2
> has a conductivity better than silver (113% IACS), and also has a high
> melting temperature of 2970 C. Its thermal conductivity is a bit low
> compared to copper, but another source (
> http://www.azom.com/Details.asp?ArticleID=492) says that TiB2 is resistant
> to oxidation up to 1000 C. Its also quite strong with good wear
> resistance,
> so it might make some decent electrodes, or perhaps electrode faces (they
> do
> use it for electrodes in electrolytic production of aluminum, so that is
> promising).
>
> BTW, www.azom.com is another handy site I like, it is also where I found
> thermal conductivity of TiB2.
>
> .Jason
>
> On 7/24/07, Tesla list <tesla@xxxxxxxxxx> wrote:
>>
>>
>> ---------- Forwarded message ----------
>> Date: Tue, 24 Jul 2007 10:43:49 -0500
>> From: Bert Hickman <bert.hickman@xxxxxxxxxx>
>> To: Tesla list <tesla@xxxxxxxxxx>
>> Subject: Re: Conductivity of metals was: Re: propeller gap help (fwd)
>>
>> Tesla list wrote:
>> > ---------- Forwarded message ----------
>> > Date: Tue, 24 Jul 2007 09:37:01 -0400
>> > From: Jason Johnson <jasonmsusolar@xxxxxxxxx>
>> > To: Tesla list <tesla@xxxxxxxxxx>
>> > Subject: Conductivity of metals was: Re: propeller gap help (fwd)
>> >
>> > David,
>> >
>> > I should have posted this link also, the first one I posted was just a
>> misc.
>> > materials table.
>> >
>> >
>> http://www.ndt-ed.org/GeneralResources/MaterialProperties/ET/et_matlprop_index.htm
>> >
>> > Jason
>> >
>>
>> Jason,
>>
>> THANKS - That page was the gateway to a gold mine of information on
>> elements and alloys... information that can otherwise be difficult to
>> find, especially all in one place!
>>
>> The parent NDT site also a variety of other resources and course
>> materials, including Eddy Current/skin depth formulas, a Java Script
>> skin depth penetration calculator, and an interesting discussion about
>> electrical resistivity and industrial versus physical units:
>> http://www.ndt-ed.org/GeneralResources/Formula/ECFormula/ECFormula.htm
>> http://www.ndt-ed.org/GeneralResources/Calculator/applet7/applet7.htm
>>
>> http://www.ndt-ed.org/EducationResources/CommunityCollege/Materials/Physical_Chemical/Electrical.htm
>>
>> Nice find!
>>
>> Bert
>> --
>> ***************************************************
>> We specialize in UNIQUE items! Coins shrunk by huge
>> magnetic fields, Lichtenberg Figures (our "Captured
>> Lightning") and out of print technical Books. Visit
>> Stoneridge Engineering at http://www.teslamania.com
>> ***************************************************
>>
>>
>>
>>
>
>
>