What is INFI?

What is INFI? Maybe to figure out what INFI is, we must first determine what it isn't. First what do we know about INFI? We know that it has cobalt. We know it shows very good corrosion resistance, and it's edge retention and toughness are out of proportion to known cutlery alloys. Keeping this in mind, I decided to do some quick research this morning to see if I could generate any new ideas on INFI. My first stop was Ron Hoods website to review his article on the Battlemistress. Very Interesting! Ron Hood gives an important clue on the composition of INFI. Ron said that a key ingredient to INFI was a metal that as far as the metallurgist he talked to knew, WAS NOT used in the cutlery industry! Hmmmmmm, what metals are used in the cutlery industry? I found that carbon, chromium, cobalt, copper, maganese, molybdenum, nickel, phosphorus, silicon, sulfur, tungsten, titanium, and vanadium are used in varying amounts in knife making in order to bring out different qualities in steel. So I eliminated them from my periodic table of elements as the "key" ingredient of INFI. If the "key" metal of INFI is not used in the cutlery industry, does that mean it is used in some other industry? Looking at my periodic table I crossed off elements that were either a)radioactive or made in a cyclotron b)would not be used by any one in the metal industry because of their properties ie., helium, xenon, iodine, etc... Still leaves alot of elements... maybe I can take a shortcut. I then decided to look up what elements begin with "I" thinking maybe Busse was giving us a clue in the name "INFI" . Iridium, a metal that is used to harden platinum, very dense (2nd most dense metal known), very brittle tending to shatter when heat treating, hmmmm...doesn't sound like a good metal for knives. Reading about Iridium led me to osmium the densest metal known to man (a brick osmium weighs 56 lbs). Hmmmm, Osmium has some interesting properties. It is very dense and is used to make alloys of extreme hardness. It is also very corrosion resistant. Where is it used? Pen tips! Did you ever notice that you will run out of ink time and time again and NEVER wear out a pen tip? That's because pen tips are 60% osmium. Sounds like maybe Osmium is a good canidate for INFI's secret ingredient. I gathered from the description of osmium that it's density and it's ability to make extremely hard alloys would mean it was hard to grind. If you had a blade of osmium, cobalt and other alloys that was hard to grind and you removed the cobalt would it be easier to grind? We know that "modified" INFI lacks cobalt and is therefore easier to grind than standard INFI. If osmium is the "key" ingredient to INFI, then removing the cobalt would decrease it's abilities somewhat but not eliminate them. Moving right along, I decided to look up what Busse's Transversion Wave technique might mean. I found that Transversion Wave in chemistry means mutation wave. Well, when making steel, austenite becomes martensite, and that is considered transversion. Using cryo-treatment (-300 degrees F) on blades to transform unconverted austenite into martensite is also transversion. What is Busse doing with his blades that he would apply for a patent? Who knows? Maybe he just found a new use for a known metal, found the way to combine that metal with other normal cutlery alloys and is simply patenting that method. Maybe in order to figure out what INFI is, we need to research the metals that are not used in knives normally. Is that metal osmium? Maybe yes maybe no. Maybe some of our more knowledgeable members can take this line of thought further.
 
Osmium is an interesting guess, but if you rule out iridium due to brittleness (I wouldn't, as alloys can get surprising properties) you should rule out osmium for that reason as well, I think. Also note that the pen tips are osmium-iridium alloys (or sometimes iridium only, in fountain pens at least).

My first guess for a not too exotic element in this context would have been rhodium. (Not that I really have any idea of what happens if you alloy it with iron.)

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Urban Fredriksson
www.canit.se/%7Egriffon/

 
I looked up more information on the platinum group of which Osmium, Ruthenium, Rhodium, Palladium, Iridium, and Platinum are all a part of, each with their own melting and boiling points etc...Of the 6 metals in this group only Ruthenium and Osmium are used to harden alloys...and from what I could gather they are used to harden the other 4 metals in the platinum group. Leaving the platinum group to researching other exotic metals used to make alloys that are Not used in cutlery world, I found Tantalum. It is a gray, heavy, and very hard material, very ductile and is immune to chemical attack at temperatures below 150C. Zirconium may be another canidate as is Niobium. These different elements are being used to produce specialty alloys (sometimes steel alloys) for use in the aerospace and nuclear industry. I think Busse has found a new use for one of these elements (listed above or not) that gives INFI its unique properties. I think I will e-mail some of these companies, give them the information about INFI and ask them what element added to steel would cause INFIs unique characteristics.
 
What's the margin of error on the analysis above? Adding it all up, I notice that there is only 1.61% of the material unaccounted for if it is precise, and I think we can assume at least 1.00% of the total is carbon.

The Chromium content is interesting, as it falls into a middle-of-the-road position that few steels occupy bewteen "stainless" and "non-stainless" types. D-2, with about 12% Chromium, is the bottom end of "stainless" in my mind, while M-2, with about 4% Chromium, is at the top end of the tool steels. INFI sits squarely between these two...

I was really expecting this steel to be a "standard" grade with a proprietary rolling and treatment method, like Carbon V. I can't believe that it actually seems to be an entire grade of steel made specially for Busse Combat, but that composition doesn't match anything I've seen.

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-Drew Gleason
Little Bear Knives
 
INFI is proprietary in both analysis and manufacture. It isn't like any thing I've ever seen before. The heat treat is pretty straight forward, if you have the right equipment. It really is a fantastic steel. If I didn't make my living making Damascus, I would use it in all my knives.

That's all I can say for now, or Jerry will cut my tongue out and fingers off!

Tim Zowada
 
Because Busse Combat has been saying that INFI has cobalt in it, and my analysis did not find any, I had it done again. The first time, the coating was sandpapered off on the handle, but since the surface was rough, not all of it came off. I have since then tapered the tang, so an analysis was done at three points along the tang on clean metal. the results were averaged and are as follows:

V .36%
Cr 8.25%
Fe 87.79%
Co .95%
Ni .74%
Mo 1.3%

I apologize for giving out erroneous results before.
 
Hmmm, interesting. Adding these new results comes to 99.39% before looking for Carbon. I doubt somehow that INFI uses only 0.61% or less C. Plus there is the chance of other elements that aren't being seen.

Is there any Osmium or other "special" alloying element being used? If so, which were you looking for?

I haven't gotten to play with the elemental analysis equipment here all that much, but if I'm not mistaken, you commonly have to specify which elements you expect to see, and then it generates a % of each based on what data is returned. If there are elements that you're missing, wouldn't that skew the results?


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JP Bullivant
 
The method used to determine the composition is a radioactive isotope spectral analysis. It will find whatever elements are present, but it can't find the light ones such as carbon. The percentage of carbon can't be determined by subtracting the rest from 100% because the error in this method is the same order of magnitude as the carbon content. Any surface impurities will also skew the results.
 
If the INFI secret is really more in the method that Busse uses in its manufacture rather than the content of the steel, can the INFI "method" be applied to different grade steels yielding better/different results? Busse mentions on his website that he is working on a steel that will make INFI obselete. Is he simply trying different steel alloys to find the one that performs the best using his method?
 
I'm not a metallurgist or a materials scientist, just a very interested amateur, but some of the language used in describing INFI led me to hypothesize that some of the secret could lie in the heat-treatment---traditionally a source of competitive edge among smiths.

I did some research in the US Patent web sites, and came up with an idea that one secret ingredient in INFI could be nitrogen, introduced into the steel via ammonia fumes during heat-treat. Perhaps it reacts with one of the above ingredients in some way to increase toughness without decreasing hardness (we've been told final hardness is 60).

Can some qualified specialist comment?

Ken Delavigne
 
The proces described above could be nitification, but that only reaches about 0,006-0,010 millimeters in to the steel, and there is a risk of flacking when surface hardening this way.
But cold the Nitrogen be added somewhere in the smelting proces, maybe forming some metalNitrates in the steel?
I am not a metalurgist only interested in the subject.

I have also read, i think on busse´s webpage that one of the secret ingredients was Nitrogen and that the secret was how it was introduced in to the steel.

Ps. every time i hear about new wonder steels , i think of master Don´s super knives?? i wonder why.

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Claus Christensen

When you have playboy channel, why get married


[This message has been edited by clausDenmark (edited 01 December 1999).]
 
This is all very interesting, but it is hard to believe that there is anything REALLY new about INFI. After all its only in the recent past, after hundreds of years of speculation, that the conclusion has been reached that true WOOTZ "Damascus" owes its properties to trace Vanadium from specific ores. Vanadium of course being now in common use as an alloying ingredient All the hocus-pocus comes down to this and HOW the wootz steel is manipulated while preserving its peculiar structure. I would think it highly probable that INFI's secret is superior manufacturing technology....or its that reverse engineering from desert ufo artifacts. Plus superior copy writing.
 
Hey SCAF,

I think that you are well on your way to developing YOUR OWN proprietary super-steel!!
I want the first Combat Master made from SCAF steel!!!!

------------------
"Come What May..."
 
Fox Creek; could you please provide your references for the vanadium in wootz steel statement? I am interested in the subject. Thanks very much, Walt
 
I thought I read that nitrogen was involved in producing INFI, and that this was not exactly something new; it had been known as far back as 1962 or so. Heat treatment no doubt also plays apart; Cold Steel states in its literature -- OK, catalogue -- that the heat treating process for Carbon V is one of their most closely guarded secrets. Anyway, it works for me; my MH is one of the sharpest and toughest knives I own.
 
walt, i can't put my finger on the specific article, but there is a good bit of stuff posted at various places on the internet. I think this was in a an article out of a British scholarly journal. Sorry i can't be more precise.
 
In another post, Mr. Busse agreed that my analysis was correct, with the addition of .11% nitrogen and .5% carbon, which the radioactive isotope spectral analysis can't detect. So, the complete formula is:

V .36%
Cr 8.25%
Fe 87.79%
Co .95%
Ni .74%
Mo 1.3%
C .5%
N .11%

These numbers should not be assumed to be exactly right, the cobalt at .95% is probably supposed to be 1.0%, but they should be close.
 
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