Mysterious titanium plate

[WValtakis]

.....

Tease

~Chip

 

[NJBillK]

The test pieces are now knives. They're thin craftsman-type knives, for cutting materials like leather and cloth on a cutting mat. The alloy heat-treated well, but acts differently than any other I've seen yet. The blades developed a chrome-like surface layer that almost looks like it's galvanized. This stuff is hard to finish.

Marked:

And finished! The top knife has the hard "alpha case" oxidized surface layer left from HT, the middle one has the strange slippery chrome-like layer, and the bottom one was ground at 80 grit in attempt to remove the layer (not exactly successful):

These are thin razor-like knives with a bit of a convex grind:

CONCLUSION: In stage 2, This stuff will make some really badass axe heads.

Have you done any testing, as far as toughness and elastic/plastic deflection?

What are the measurements of these knives BTE and aprox. bevel angle (if it were not a convex)?

 

[Mecha]

Have you done any testing, as far as toughness and elastic/plastic deflection?

What are the measurements of these knives BTE and aprox. bevel angle (if it were not a convex)?

That's hard to say. The blades are "crisp" and stiff but they do flex. As for the angles, the main bevel is probably less than 10 degrees inclusive (5 degrees per side). The bevel is clearly more narrow than an Opinel. The cutting edge, guessing from the angle the blades were held, is maybe 18 degrees inclusive, maybe less. Don't know for sure.

As for testing, I sliced up some double-thick cardboard and leather and they worked fine, especially on the leather. The edge is a bit more toothy than the other alloys I normally use, which are very smooth.

 

[NJBillK]

That's hard to say. The blades are "crisp" and stiff but they do flex. As for the angles, the main bevel is probably less than 10 degrees inclusive (5 degrees per side). The bevel is clearly more narrow than an Opinel. The cutting edge, guessing from the angle the blades were held, is maybe 18 degrees inclusive, maybe less. Don't know for sure.

As for testing, I sliced up some double-thick cardboard and leather and they worked fine, especially on the leather. The edge is a bit more toothy than the other alloys I normally use, which are very smooth.

This is great news, I am thinking about trying to get my hands on one, things will be tight.

- What do you think the "toothiness" could be attributed to?
Likely a carbide structure, but do you have an estimate of what type?

- How do you think the edge holding would compare between the two?
I am trying not to compare to steel alloys, but it is what I am more familiar with. Due to this, I am thinking along the lines of carbide volume (AEB-L or 14c vs 440v/S60V, 440C/ATS-34)?

- Have you tried differing HT protocols?
If so, they likely originated from your known alloy HT and were tweaked.
- If this is the case, we're the adjustments something that you would consider "non-opportune" for your previous alloys?

- Did the use/HT of this new alloy spawn any new ideas for your main alloy?

- Do you think your work with your "regular" alloy will gain anything from your work and experimentation with this new alloy?

- Is there a particular reason you went with this blade profile?
- Would a shorter blade height (say a more traditional wharncliffe) be prone to cracking, or is it simply that these bear more of a resemblance to your personal "blade style"?

 

[palonej]

All I wanna know is will the edge be damaged from chopping concrete at those edge angles??
Everyone knows that’s the only attribute that matters........some guy named Gaseous told me.
Thanks in advance!

Joe

 

[NJBillK]

All I wanna know is will the edge be damaged from chopping concrete at those edge angles??
Everyone knows that’s the only attribute that matters........some guy named Gaseous told me.
Thanks in advance!

Joe

With the edge being that thin, there will be some competition in his chosen area of knife concealment.

Which do you think is smaller?

 

[Mecha]

This is great news, I am thinking about trying to get my hands on one, things will be tight.

- What do you think the "toothiness" could be attributed to?
Likely a carbide structure, but do you have an estimate of what type?

- How do you think the edge holding would compare between the two?
I am trying not to compare to steel alloys, but it is what I am more familiar with. Due to this, I am thinking along the lines of carbide volume (AEB-L or 14c vs 440v/S60V, 440C/ATS-34)?

- Have you tried differing HT protocols?
If so, they likely originated from your known alloy HT and were tweaked.
- If this is the case, we're the adjustments something that you would consider "non-opportune" for your previous alloys?

- Did the use/HT of this new alloy spawn any new ideas for your main alloy?

- Do you think your work with your "regular" alloy will gain anything from your work and experimentation with this new alloy?

- Is there a particular reason you went with this blade profile?
- Would a shorter blade height (say a more traditional wharncliffe) be prone to cracking, or is it simply that these bear more of a resemblance to your personal "blade style"?

Well, these little rounded knives arose because recently leather construction droid Ms. Oye and I were talking about insufficient leather cutting tools (we don't have a real round knife). One of my grade 38 ti knives was hanging around getting a new sheath, and it would easily sink right through the leather and down deeply into the cutting mat with no effort, compared to sawing back and forth with a carbon steel Opinel etc. that gets dull pretty much immediately and just doesn't have that aggressive bite.

Since the tester strips from the mysterious plate were so wide and thin, it was decided to try out something like a little one-hand round knife for craft work. Future knives could benefit by refining the design a bit. The Opinel is a useful knife and that's why it's still around, but it doesn't compare at all in cutting ability or edge retention to the grade 38 knife or even these experimental knives, as far as I can tell. Don't know how to compare to the steel alloys listed above.

The slight toothiness is due to one of the mysterious alloying elements, same with the slick chrome-like outer layer. Most titanium alloys are not prone to cracking, and a different knife shape wouldn't change that. My normal work with all ti alloys benefits from every new blade or new alloy that gets tried, as I get to observe the behavior of a new alloy or design change and compare. Of course it's better when I know what the alloying elements are! This stuff will still get tested with a mass spectrometer before the axes are made so it's known for sure.

My normal HT protocol was used for these. Industrially, all ti alloys all use basically the same HT protocol, and the final characteristics are altered by changing the alloying elements, not the HT. These and the others are done by observing the phase change of the alloy first-hand, and applying the principles of ti metallurgy by eye like an old time smith. Similar to using carbon steel in a coal forge, except every part of the process is somewhat different. Any tweaking of the protocol is done in real time due to observing decalescence. They all react differently to heat, and the methods used are specifically for making blades, so the final product is a lot different than what you would see in normal ti structures or raw bar stock.

So far the best ti alloy I've used for a knife is grade 38, several of which tested at HRc 55-ish. If you're thinking about getting ahold of one and want the best knife that I can make so far, that's what I'd recommend. However I just finally got ahold of another alloy that may meet or beat even grade 38: a Russian alloy called BT23. For longer swords subjected to ridiculously heavy impact, the best so far is still Ti Nb.

 

[Mecha]

All I wanna know is will the edge be damaged from chopping concrete at those edge angles??
Everyone knows that’s the only attribute that matters........some guy named Gaseous told me.
Thanks in advance!

Joe

LOL! If there is one thing a ti alloy knife can DEFINITELY not do as well as steel, it's chopping concrete!