Titanium knives marked and quenched

Mecha

Mecha

Titanium Bladesmith
Knifemaker / Craftsman / Service Provider
Joined
Dec 27, 2013
Messages
10,017
Hi folks!

I want to share a few quenching photos of forged beta titanium knives. Still fine-tuning the process, but I'm really happy with this batch, and I think the HT is going to be very nice.

Rough grind: really having a blast with my newly modified 2x72 grinder!
BLbm1AA.jpg



Marked: still doing this with a point and a single oval, so each mark is actually four overlapping marks, haha.
Q0eh6Qi.jpg



Quenched: I think this will prove to be my most "potent" ht yet.
UCVLynE.jpg



Cleaned: A little WD40 makes everything look nice!~
0a5oFmg.jpg



My whole circus revolves around sword-making, but everyone wants knives. Bah! :D
The alloy is approximately 89.5ti 10nb 0.5fe.
 
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mecha! I see good things coming. And, I see mine.
I have a Tikat or I'd get a sword from you.
RockOn!!
rolf
 
Video of these knives getting dunked:

https://www.youtube.com/watch?v=AggQuChU3bE&feature=youtu.be

Pure clean cold water. Titanium hates oil.* And HELL NO I'm not cutting these ridiculous bars by hand! Reciprocating machines may be ultra sexy, but even the power hacksaw takes 15 minutes to make a cut.



*I read of one ti alloy that likes oil, but it's stupid
 
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mecha- A piece of your madness will soon be on my hip.
Thanks.
rolf
 
Here are these knives with deerhide + cow sheaths and grips. The third one will have a sheath covered in white deer.

yoFdO2a.jpg


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Above them is my favorite hammer ever, took me almost 2 years to PRY it out of the farrier who owned it, just got it tonight! It hammers a fantastic billet! :D
 
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I should have a good idea of their hardness soon; I'll post the results for ya!
 
Well, according to my new tester these should be just around Rc 47. Still reaching for that magic number of 53! :)

Edit: Been testing every ti blade or blade fragment around, getting readings in the 40s.
 
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Alloyed bronze and copper reach Rc 45.
Very interesting what you're doing, Mecha. :)

Doug
 
For what it's worth, this monstrosity defeats my welding table in an unscientific edge-on-edge contact test! :D

m3pb43T.jpg


dw3v8qN.jpg


Small gouges on the sharp blade edge, big cuts in the steel table is good, right? :p
 
Mostly just rolling a bit.

Viola! Good as new!

Zk3oFfJ.jpg


Bc82K0s.jpg
 
So what is this Ti specifically called?

6al4v is considered an alpha-beta alloy, grade 5.
6al4v has a Rockwell hardness of 36, and can be heat treated. But I can't find much info on what ht'ing will do for 6al4v. Specifically how much harder can 6-4 Ti get?

Your Rockwell hardness of 47 is much harder than un-heat treated 6-4.

I guess what I'm getting at is who ht's regular 6-4, and what do they achieve?

Hope to have others chime in on their 6-4 ht outcomes for some more real world comparisons.

Sam, I have a link about 6-4 Ti heat treating. Curious what your methods and time cycles are. We'll hit that up more in PM OR IN PERSON. :). Damn caps lock...

Rolf!,,,, word.
 
I love guys like Sam. They just push forwards.
Hi Chris and good questions, mano.
 
Thanks Lycosa :]

Sloth:

There's no grade number for the alloy I'm using. It's metallurgy name would be 89.5Ti 10Nb 0.5Fe ; 90Ti 6Al 4V would be grade 5.

Grade 5 can get at least into the low to mid 40s on the Rc scale. It's usually hardened with snazzy tempering, aging and precipitation hardening, etc, basically fine-tuning the grain structure and crystal lattice with heating and cooling cycles. It also work-hardens well, and all the hammering and forging in my grade 5 test billets yielded hardness around Rc 42, after just air-quenching. Very flexible and tough in this state.

The natural crystal lattice of titanium is hexagonal-close-packed (alpha phase), but the beta phase, which forms above the beta transus temperature of about 1680 F, is body-centered cubic. If the titanium has enough concentration of "beta stabilizer" elements alloyed with it, quenching the billet after this temperature will cool the bar down so quickly that the cubic crystal lattice is locked in and retained at room temperature, instead of reverting back to HCP as the bar cools. The ability to be stable at room temperature in the BCC phase is what makes the alloy a "beta" alloy. True beta alloys are going to hold a mix of alpha and beta phases like grade 5, but the phases are more controllable and open up possibilities for some very useful grain structures. The one I'm concerned with at the moment is alpha prime, which is basically titanium martensite. I've seen studies that showed beta titanium ballistic armor plates over Rc 60 due to alpha prime (though they were brittle).

The hardest blade I've made yet is reading Rc 51, which is damn near where I want to be for swords! There's more to it, like what individual alloying elements do in solution and how they can dramatically affect the metal's qualities and so much more. Sorry for the long-winded response. It's just like with all the fantastic iron alloys out there, and how everyone loves to discuss the subtleties and qualities of their favorites!
 
Sounds like you are getting close. The 51 is with your Ti or the 6-4?

And the "name" of the Ti you have indicates no vanadium? So all the cutting is done from the niobium? Which I did some reading on... Niobium is a very cool element... And I think is what is giving you that coloring, as it is a jewelry type element as it anodizing really well.

Keep at some testing and updates, later!
 
The 51 is with the beta alloy; it has no vanadium. The niobium is the beta stabilizing element, and it has a lot of nice effects on titanium: heavy in weight, greatly increased resistance to oxygen/atmospheric contamination at heat, and makes hard grain structures in the alloy. The iron is a strong beta stabilizer, it diffuses into very fine grains within the alloy, and causes it to deep-harden toward the core during a quench!
 
Cool info. ^
The late John Moore of Mission Knives told me that his Ti knives were run over by tanks, hit with bullets, blown up and they held up fine. I ordered my first Ti knife from Mission after hearing this. lol!!
 
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