On Mon, 23 Jan 2006 17:29:27 GMT, "Lloyd E. Sponenburgh"
wrote:

,;
,;"Cliff" wrote in message
...
,;However, tungsten carbide _tooling_ is an alloy or solution of the
,;compound
,;and metal (usually cobalt).
,;
,; Usually the Cobalt is a binder for the sintering IIRC.
,;
,;I'm reasonably sure that it can serve either as a sintering binder OR be
,;used in a true alloy.
,;
,;I'd have to cite source to back up my claim, but we all know how much ire
,;"cutting and pasting" raises around here.

I worked for the largest producers of cemented tungsten carbide for
over thirty years. Believe me when I tell you that the purpose of the
cobalt is to cement the carbide particles together. Cobalt "wets" the
carbide and is reasonably high melting. Both are essential. Is there
some surface penetration? Probably... but it is not an alloy period.

I have been retired for over twenty years but my recollection is that
the cobalt content runs about 10%.