Re: [Phys-l] Help needed: Thermal conductivities of alloys?

[Bernard Cleyet <bernardcleyet@redshift.com>]

Very good.

Before being reminded of the W-F law, I was going to suggest the the 
weighted average is probably not valid.  This is because the alloys' 
atoms usually have different sizes, so alloying produces defects that 
impede diffusion, i.e. the conductivity may be poorer than either pure 
metal.  They also impede grain movement, which is usually the reason for 
alloying! 

bc, who was concerned w/ the W-F law when he worked for a company 
researching thermocouples.  [Excuse; ca. 1959]



John Denker wrote:

> On 10/24/2006 03:43 PM, Savinainen Antti wrote:
>  
>
> > ... thermal conductivities (k) for the alloys 
> >    
>
> You can get this from the observed electrical resistivity via
> the Wiedemann-Franz Law.
>
> The physics is simple:
> -- electrons are responsible for carrying the electricity.
> -- electrons are the dominant contribution to carrying the heat.
>
>  http://hyperphysics.phy-astr.gsu.edu/Hbase/thermo/thercond.html
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