On Tue, 20 Sep 2005 20:34:40 -0700, wrote:

I want to minimize the toxicity.
(I realize that copper itself can be toxic)

I'm looking for easy to machine copper.

I'm told that machining pure copper is a bear.

I need the melting point and thermal conductivity of copper.

I'm going to machine away l away 95% of the 4" bar.

Any suggestions?

(I'm the same as the origional poster, just differn home/work account)




On 21 Sep 2005 02:38:19 GMT, (DoN. Nichols)
wrote:

According to machineman :
wrote:

Where can I purchase some 3 to 4" tellerium copper rounds?
(Or any easily machined copper)
I'm looking for some rounds 16 to 18" long.
I expect they will be expensive

[ ... ]

http://www.anchorbronze.com/c14500.htm

Also -- consider the toxicity of it. It is not known to be as
bad as beryllium, but it does have some known effects. From the web
site: http://www.corrosionsource.com/handbook/periodic/52.htm

================================================== ====================
Tellurium and its compounds are probably toxic and should be
handled with care. Workmen exposed to as little as 0.01 mg/m^3
of air, or less, develop "tellurium breath," which has a
garlic-like odor.
================================================== ====================

Also -- FWIW, the entry concludes with the following:

================================================== ====================
Costs:

Tellurium costs about $100/lb, with a purity of about 99.5%.
================================================== ====================

I found this (and lots of other hits -- around 18,000) by
running a Google search on "tellurium breath", which I remembered as an
effect of the stuff. Some of the others suggest that once acquired, it
lasts for months.

Enjoy,
DoN.
Have you checked the thermal conductivity of tellurium/copper alloy? I
don't know what it is but do know that several copper alloys lose lots
of thermal conductivity compared to pure copper. Pure copper is tough
to machine, but if you only need one just use pure copper. If you need
several maybe casting them work.
ERS