[volt-nuts] Low thermal EMF solder

[Bruce Griffiths]

Bruce Griffiths wrote:
> Mark Sims wrote:
>> I am in the process of making some low thermal EMF cadmium-tin 
>> solder.   This material has not been manufactured in a very long time 
>> and is pretty much unobtainable these days (despite it being listed 
>> as the product of several companies in India).  It gives the safety 
>> geeks apoplectic fits at the mere mention of the first syllable of 
>> "cadmium"...
>>
>> I have seen references to 60:40 solder and 70:30 Cd:Sn solder.   At 
>> one time I saw a table that showed the characteristics of a few type 
>> of Cd:Sn solders,  but have been unable to locate it.  Does anybody 
>> have any references to the properties of Cd:Sn solders?
> The cadmium tin eutectic has low thermal emf and a 30:70 Cd:Sn 
> composition.
> For some micophtographs of the structure of the solid eutectic:
> http://www.aimehq.org/search/docs/Volume%20071/071-48.pdf
>
> Bruce
>
For a plot of the melting point vs composition see:
http://resources.metapress.com/pdf-preview.axd?code=hu72j65756220274&size=largest 
<http://resources.metapress.com/pdf-preview.axd?code=hu72j65756220274&size=largest>

Which establishes that the eutectic has an approximate composition of 
30:70 Cd:Sn.

For the full article on the Cadmium tin system:
http://www.springerlink.com/content/hu72j65756220274/

Bruce