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Posted to alt.machines.cnc,rec.crafts.metalworking
Unknown
 
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Default OK what is the diferance between carbide and powdered metal ?

On Tue, 24 Jan 2006 01:10:19 GMT, BottleBob
wrote:

,;Unknown wrote:
,;
,;
,; Tungsten carbide is a compound but the finished
,; product you refer to as "tungsten carbide _tooling" is better called
,; cemented tungsten carbide. The cobalt is not in solution but is found
,; at the interface as a glue (cement).
,;
,; In practice the cemented carbide tools frequently are a mixture of
,; carbides cemented with cobalt metal.
,;
,;Unknown:
,;
,; Ahh but the question IS; can tungsten carbide tooling (since it is an
,;intimate "mixture" of tungsten, carbon, and cobalt), be correctly
,;referred to as metallic or a metal since the finished product has
,;metallic properties?


First it is not a mixture of tungsten, carbon, and cobalt. It is a
mixture of tungsten carbide and cobalt metal.

If you tell me it has metallic properties I would agree. If you tell
me it is a metal then I would say you are wrong.

Let me give you another example of a product we made. This was a
mixture of glass, silver metal, and epoxy. The product was silver
coated tiny glass spheres "cemented" together with epoxy. The finished
material was used as a conductor in those ancient multi-flash units
that mounted on film cameras. There were eight flash bulbs per unit.
The epoxy cemented the spheres tight enough so the material conducted
electricity. There was damned little silver in this material but those
silver coated glass spheres traced on the ciruitboard conducted
electricity and the trace looked shinny metallic. This material
certainly has metallic properties so by your reasoning you would try
to convince me that this material was a metal. Unsuccessfully I might
add.

Well perhaps not and perhaps now you will see that just because it
looks like a metal and has some metallic properites it is not
necessarilly a metal.

It is different than "if it looks like a duck and quacks like a duck
it is a duck.

I am a chemist and spent an entire career working in a metallurgy
department in a large industrial research labatory so my view of these
things probably is different than most in this newsgroup. For my usage
as a chemist when you add additional elements in any significant
amount it no longer is a metal.

Just because the sales and marketing people use terms such as
"hardmetal" or "heavymetal" it doesn't fit my definition of a metal.
Now if it fits yours I don't have a problem with that but I will tell
you that you are going to be on a slippery slope fitting your
definition to a lot of commercial products.