INFI vs. 60 NiTiNOL PM?

OldPhysics said:
...many alloys and mixtures have been 'invented,' forgotten, and then re-discovered again.
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However, 60 NiTiNOL PM (Powder Metallurgy) from Crucible is a new alloy based off of old NiTiNOL. The only reference I have found regarding NiTiNOL PM states that "[t]he limitation of Nitinol PM processes appears to be the oxygen content...[whereby o]xygen at these levels may not significantly affect shape memory effect or superelasticity, but may negatively impact ductility and fatigue resistance". Further developments and refinements by Crucible may have led to a fabricated product in which ductility and fatigue resistance were not negatively impacted.
 
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a good general use knife material should have these properties:

-enough corrosion resistance that it won't rust while you watch it
-the ability to take lateral and torquing stresses across the width of the blade
-not chip/fracture/shatter/explode/spontaneously combust under localized stress (knot in wood bending a small portion of the blade)
-present enough plasticity to deform at the edge rather then chip
-maintain an edge under blunting forces for a reasonable amount of time
-be able to be sharpened on a standard sharpening stone (not requiring specialty carbides etc)
-be able to take an moderately acute edge without losing all of the above properties (24 degree's per side)

now, take anything from that list and make it "very light stress", and i bet nitinol will do just fine. but when you get into "moderate stress" and "heavy stress", can nitinol really cover all those grounds?

cause if it cant - especially infi's specialty of plasticity at high hardness, it isn't a comparable material. it may win out on abrasion resistance and corrosion resistance, but if you can't bang it on a rock every now and again (which you WILL do while clearing wood if you do it regularly), then it's a specialty steel that isn't in the same scope of work or use.

*note: aus8a covers all those bases. it just doesn't do as well when you start increasing the stresses and the intensity of each feature.
 
Superelasticity at high hardness is a supposed benefit of 60 NiTiNOL PM as the Strider offerings are being touted as having a hardness of HRC 65.
 
adamlau said:
Superelasticity at high hardness is a supposed benefit of 60 NiTiNOL PM as the Strider offerings are being touted as having a hardness of HRC 65.
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one does not necessarily follow the other. unless strider is claiming that their heat treat retains the superelasticity feature of the steel - assume that it does not. being high hardness and plastic to a certain degree is not the same thing.

the harder you make something, the more likely it is to break, so I question whether the superelasticity feature would actually be functional at that hardness, even if it was actually present. if it goes back to shape when heated, it doesn't really make any difference when there's a fracture in place.
 
from what ive heard from a close friend to strider. the nitinol with a new heat treat by strider can be hardened to 65 but still be superelatic. they also said that some of the nitinol was elastic at room temp. but there is a problem with this metal. because it is 50 to 55% nickel. that means that you wont be getting the same hardness or elasticity everytime. making it unreliable. but i saw one of these knives and i will say i am impressed with the sharpness and clean cuts it can do. it does have a weird feeling to it. I know jerry knew about this long before all of us lol and if he thought it was better he would be using it. you never know maybe a combo of nitinol and infi would be sweet. im guessing the nickel is what is giving it the elasticity and the titanium the hardness. if you "can" find a heat treat and reproduce the alloy with 52-53% nickel then maybe they got something. but until then this knife is just a safe queen.
 
Has anybody actually compared this steel to INFI? I would like to see some hard facts, not just speculation.
 
suttond said:
Has anybody actually compared this steel to INFI?
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It's not steel: it's about half Ti, half Ni, no carb, no Fe.
As for hardness, it doesn't tell the whole story. Some material display high hardness with low wear resistance (notably certain armor steels).
 
like i said before i have handled a nitinol folder and it performed just like a sv30 blade i thought. now i didnt abuse it to see what it could do so i cant really say how it holds up to infi but if you read my earlier post youll see what i thought
 
Re: The New Metal. I'll quote a beautiful, and intelligent woman...
BRING IT!!!
:D
 
With INFI being non-specific, any new and improved metal can be called INFI by the Busse Combat Knife Company.

It would likely still be the best available.
 
resinguy said:
I would like to assume that Busse is not resting on it's laurels, but instead that Jerry keeps a watchful eye on new steels, gets a sample if the paper specs appear promising, makes some knives, beats on them unmercifully, and casts them aside as found wanting. If and when he finds a steel that provides a better all around balance of properties than INFI, he would switch.
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This is what I think too, Jerry has made knives out of other Steels. A2 for example. Then Modified INFI then INFI, I am sure if something were better all around than INFI than he would switch too it. If not just switch too it then tell us whats up, what he's found to be better and why he would change too it.

Kinda like what I said before, but cost might also hinder things too.
 
papathud said:
With INFI being non-specific, any new and improved metal can be called INFI by the Busse Combat Knife Company.

It would likely still be the best available.
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This is a good point. It could well be that INFI has changed, and we would not necessarily know.
 
in late 2000, I was offered to test a Nitinol knife. Nitinol is a Ni/Ti mix, the proportions of which vary with the purpose. Everyone makes it different and the stuff has been around a long time. Those cool twisty frames you can buy for glasses are nitinol, not Ti like most people think. Anyway, the manufacturer told me that this nitinol knife was amazing and would revolutionize knife making. He said that there was already about 100 in the hands of other users. I got the knife and was told to abuse it and that it was extremely tough. I barely did a light flex test and the dang thing snapped in 3 pieces, I called the guy and told him and he could not believe it. I told him that my Mission MPK and my Busse could do that all day long. Never heard from him or his company again. lol.
 
Cobalt--- You used Mission and Busse in the same sentence??!! :eek:
Thanks for the story. :thumbup:
 
papathud said:
With INFI being non-specific, any new and improved metal can be called INFI by the Busse Combat Knife Company.

It would likely still be the best available.
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if infi is patented it has to be specific. if it's just copyrighted, then yes it could be anything, because the copy right would only cover the name. the patent office doesn't really let you change the specifics of your patent and maintain legal ownership, unless you want to file for a different patent, or your initial patent covers the new design as a possible variation.
 
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