Hardness of Titanium on the HRc ? ? ? ?

So I know Titanium is light and strong and all that, super, but except for titanium carbie I've not heard anything about hardness or wear resistance principles. I was thinking of getting a titanium crowbar and that got me thinking, also I've heard of titanium bladed knives. So anyway, my question is this, what is Titanium like on the Rockwell C scale, any help would be appreciated and thanks in advance! :-)

Reply to
good2get2know
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It ist not very much wear resistant.

AFAIK, Titanium hardness ist too low for HRC.

Michael Dahms

Reply to
Michael Dahms

For the very common Ti-6Al-4V alloy, expect about 30-36 HRC, depending on microstructure. It is possible to get into the low 40's with work hardened beta alloys like 38-6-4-4. Yet as the knowledgeable Michael Dahms notes, the wear resistance is poor. The edge holding ability is also poor, so I believe that titanium alloys are just wrong for knives. Great corrosion resistance, of course, and it's sufficiently expensive with an impressive reputation for strength to weight ratio so as to make it marketable as exotic.

If you do make Ti alloy knives, look into coatings for the edge. I'd recommend either a PVD coating like TiN or some varient of that type, OR a nitriding process like Nobleizing, which we have done at Flowserve in Tennessee.

Reply to
gearloose

Who makes those ? I've seen hammers, but not a crowbar. Could be useful

- you don't need much of an edge on it.

Only for saltwater diving, and they're not even very good at that. Titanium knives are, by and large, a bit of a let down.

Depends on the alloy, and it's all going to be pretty low. 6/4 alloy is the hardest you'll get - Google or Machinery's Handbook for the magic numbers.

The one time I've ever heard comment about Ti hardness (and that not positive) is in bike frames. Frames are made of several alloys, cp (pure), 3/2.5 (strongest alloy you can get seamless tubes in) and 6/4 (strongest, but the tubes have to be welded). The 6/4 frames are known for having rear dropouts so stiff and with such surface hardness that you can't get a nut and bolt to grip. Unless you use a fitting done up with a tool, the typical hand-tightened bike wheel locating skewer is prone to slipping out of the dropout if you hit a bump!

Reply to
Andy Dingley

Those are only the alloys that are the most common. "3/2.5 (strongest alloy you can get seamless tubes in)" Not true. I use seamless Ti 6-4 in thin wall seamless at 1.5 " OD and 0.032" W.T

"6/4 alloy is the hardest you'll get." Not true. I know of alloys that exceed 200ksi. Higher strength should be possible." I have a piece of Ti

15-3-3-3 seamless tubing 1"od x 0.028 wt that I use for a hiking staff. It has a strength of 186ksi.

"stiff and with such surface hardness..." Not true. The stiffness of Ti is roughly half way between steel and alum>

Reply to
bainite

Reply to
bainite

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