"RicodJour" wrote in
ups.com:

On Nov 24, 4:04 pm, "claude" wrote:
Is there someone out there who can clarify a mystery for me. I have
just bought all sorts of titanium drill bits and have other tools
that they say contain titanium. I don't get it, working on a titanium
aircraft part with a normal chrome molly tool will destroy that
titanium part. So how can they alloy or coat a drill bit that won't
react to itself or to the part you are working on at the molecular
level? The only explanation I can think of right now is that the
titanium they mention is bull and is just a fancy colored coating.

The tools work well enough but I am a very curious individual.

It is not a titanium coating. It is a titanium _oxide_ coating.


WRONG;it's titanium NITRIDE.
Almost as hard as diamond,excellent wear resistance.

titanium oxide is a pigment used in white paint.


Oxides are frequently far harder than the principal element. Aluminum
oxide, one of the softer metals, is used as an abrasive and is very
hard.

R



Strange,because aluminum oxide forms on any piece of bare aluminum exposed
to oxygen or ordinary air. And carbon steel drill bits drill it easily.
Of course,it IS harder than WOOD,so it's used for cheaper sandpaper.
It's not very hard compared to other abrasives.

--
Jim Yanik
jyanik
at
kua.net