A very quick and close look at 'steeling'

[knifenut1013]

A ceramic stone can be refinished to a finer grit, its how spyderco makes the UF ceramic.

As me2 noted it seems to have some "steeling" or what I consider burnishing along with its abrasive qualities. To me this is more a result of its high hardness and density of the ceramic and goes along with the infinitely rigid discussion lagrangian and I had in another thread. The ceramic being a more rigid object pushes back on the steel blade being ground on it with such force any more than a feather touch in some cases will cause chipping or excessive deformation. I noted this in my use of ceramics and how just placing the edge on the stone at a incorrect angle or with too much pressure would cause the metal to be deformed at the edge.

Great thread, BTW

If you don't mind running some more tests I think it would be interesting to see a damaged edge repaired by the steel. Show the before and after of edge rolls and what happens to the high spots in a deformation. Also excessive steeling, say 100 passes or more?

[tiguy7]

As I understand it, the black ceramic kitchen knives are made from hot isostatic pressed Zirconium carbide with some Alumina present. Kyocera markets a 7" Santoku black chef's knife with a very smooth finish (glassy) that is supposed to be exceeded in hardness only by diamonds. The plastic handled model sells for less than $100. I use this and other ceramic knives to steel my metal blades. My "steel" is also a useful kitchen knife.

[Lagrangian]

Hi knifenut1013,

I was pointed to the following thread by either Tom Blodgett or Ken Schwartz. The user yuzuha on the www.foodieforums.com posted some microscope photos of the Spyderco Ultra-Fine hones, and microscope photos of the resulting surface finish. Unfortunately, it seems the photos are now broken links, but the text of her post is still available, and she says that she sees burnishing in the resulting surface finish.

"Leaves the burnished part nice and bright the surface isn't exactly smooth."--yuzuha on wwwfoodieforums.com
http://www.foodieforums.com/vbulleti...3422#post23422

It seems that the Spyderco ultra-fine hones leave a fairly complex finish which cannot easily be characterized by a single grit number. Sal says so himself, which is why Spyderco does not provide a grit number.

"We've spent a great deal of time trying to determine grits for our stones. The manufacturer has also worked with us, to no avail. A guess seems to be best. Most abrasives are measured by the grit size used in the matrix. Our ceramic doesn 't work that way. Grit size is constant. We've tried to compare scratch patterns as Cliff [Stamp] mentioned and this is probably the closest, but nothing that we can say "This is blah blah". Then the Japanese water stones jump into the equation and suddenly there is whole new set of numbers."
--Sal Glesser (brackets mine)
http://www.spyderco.com/forums/showt...490#post395490

Sincerely,
--Lagrangian

[knifenut1013]

I've seen the pictures, I've read most all of Pam's postings and learned a great deal from her on natural and synthetic waterstones. When I had troubles with my ceramics I did some searching and found her threads and pictures, amazing what a picture can tell you.

[Lagrangian]

As I understand it, the black ceramic kitchen knives are made from hot isostatic pressed Zirconium carbide with some Alumina present. Kyocera markets a 7" Santoku black chef's knife with a very smooth finish (glassy) that is supposed to be exceeded in hardness only by diamonds. The plastic handled model sells for less than $100. I use this and other ceramic knives to steel my metal blades. My "steel" is also a useful kitchen knife.

Hi tiguy7,

Wow, that's interesting! I didn't know about the zirconium carbide used in ceramic knives. All I had heard about previously, was just the zirconia part, with some additives (such as yttria).

"The hot-pressed black ceramic knives has a special blade made of zirconium carbide, which turns black when fired. Zirconium Oxide is even more resistant to damage from misuse or dropping."
http://www.metrokitchen.com/about_kyocera

I haven't heard about alumina in ceramic blades. Do you have a reference or citation for that?

Almost all ceramic knives are zirconia based. There are a few exceptions, as Boker sells some ceramic blades that are not zirconia (I believe this is their Cera-Titan line).

Most ceramics are incredibly brittle, which means they have very little fracture toughness (as described by me2 earlier in this thread). So to be useful for a knife, or a hammer, the ceramic has to be specially toughened. I won't go into the details, but transformation toughned zirconia (also mentioned by me2 in this thread) is an amazing cool material.

You can read about transformation-toughened zirconia, and an incidental connection to the Coors beer company in the wonderful book: _Why Things Break_ by Mark. E. Eberhart.
http://www.amazon.com/Why-Things-Bre...6605192&sr=8-1

Wikipedia also has some material about ceramic knives and transformation-toughneed zirconia (also knowns as yttria-stabilized zirconia):
https://en.wikipedia.org/wiki/Ceramic_knife
https://en.wikipedia.org/wiki/Yttria...lized_zirconia

Interestingly, ceramic hammers, made of zirconia were/are manufactured by Coorstek, a company that has spun off of the Coors beer brewery. It sounds weird, but years and years ago, Coors used to make ceramic tools, including ceramic hammers. Why a ceramic hammer? well, it's for those applications where positively absolutely you cannot afford to generate a spark. If you work in the natural gas industry, or explosives/rocket-fuel, then you know why this is a good idea.

Metal hammers spark when you chip off a tiny tiny piece of iron, and it combusts (to form iron oxide; or rust). Many ceramics are metal-oxides, so well, they're already burnt and cannot burn again! (Okay, not under "normal" situations.) The problem with this is, most ceramics are brittle, which is not good for a hammer. So the hammer is made of a special type of ceramic: transformation-toughened zirconia.

"Though Coors is well known as a brewer of beer, it is less well known as the world's largest producer of specialty ceramics producs. This particular hammer was made from transformation-toughened zirconia, a polycrystalline material made from the oxide of zirconium."
--_Why Thinks Break_ by Eberhart (2004)

This snippet and more can be read from Google Books:
http://books.google.com/books?id=e6e...hammer&f=false

A picture of a Coors ceramic hammer:
http://ceramicsmuseum.alfred.edu/exh...us/hammer.html


BassLakeDan on the WickedEdge forums pointed to some additional history for the Coorstek company:
http://www.coorstek.com/history.asp

Sincerely,
--Lagrangian

P.S. The above post is similar to one I made in the www.WickedEdgeUSA.com forms. Sorry if this post is rather disorganized; I was in a hurry and simply reused parts of my other post. You can find that thread here:
http://wickededgeusa.com/index.php?o...t=18&Itemid=63

P.P.S. I think the hardness of zirconia is around 70 on the HRC scale. I looked up the hardness of zirconia, which is often given on a different hardness scale (such as Knoop Hardness, or Rockwell A Hardness, etc.), and then can be (approximately) converted to Rockwell C Hardness.
http://www.tedpella.com/company_html/hardness.htm
http://www.grantadesign.com/images/hardness.fe2.gif
http://www.gordonengland.co.uk/hardn...version_1c.htm

The Vickers Hardness scale has one of the widest applicable ranges. Under the Vickers scale, zirconia is pretty darn hard. But it's not as hard as many things. So it is not accurate when advertisers say that Kyocera's zirconia ceramic knives are second in hardness only to diamond. Even aluminum-oxide is harder than zirconia. Aluminum oxide, as hard as it is, is only about 1/4th the Vickers hardess if diamond, and even cubic-boron-nitride is about half the Vicker's hardness of diamond. More or less, it is accurate to say cubic-boron-nitride (CBN) is second in hardness only to diamond. May not be litterally true, given other materials (I forget how hard borazon is) and maybe research materials like nano-carbon-tubes, etc. But probably true enough to say so in an industry presentation.

Also if you are curious, diamond does not have a single hardness, because it is harder along some crystal axes than others. But it's reasonable to give an average of these hardnesses.

I really like this plot from http://www.gordonengland.co.uk. It shows the hardness of many common very hard materials. It also illustrates that Rockwell C Hardness is not linear in Vickers hardness. Although it is not obvious from the plot, but an infinitely hard material would have a Rockwell C Hardness of 100. This is a peculiarity of the Rockwell Hardness Scale, which you can read about on the www.gordonengland.co.uk website.
http://www.gordonengland.co.uk/hardness/ehe.htm
http://www.gordonengland.co.uk/hardness/rockwell.htm

[Lagrangian]

Unfortunately, it seems the photos are now broken links, but the text of her [yuzuha's] post is still available, and she says that she sees burnishing in the resulting surface finish.

I don't know how to solve the problem of broken image links in forums. Please consider that we are today, six years later (!), still interested in yuzuha's photos but cannot access them. If possible, please bind the image directly as an attachment to your post (so that it is hosted by the forum server, and not a 3rd party), or else use an image repository which is likely to be stable, such as http://imgur.com. Do not use web-space from an account attached to your ISP; that will go away if you change ISP's (say, if you move, or change from DSL to cable modem).

I suspect even a decade after the date of yuzuha's post, in the year 2026, we will still be interested in her photos, but sadly, they will be gone.

So on behalf of future knife sharpeners, please try to post your images in a way which will be stable for years to come.

Sincerely,
--Lagrangian

P.S. As a programmer, we know that often the code we write can live longer than us. Consider that some of the code in UNIX was written in the 70's and is still with us today; some of it completely unchanged. That has litterally outlived many of the creators and contributors to UNIX.

Verhoeven's technical report _Experiments on Knife Sharpening_ (2004) is now eight years old. But I am willing to bet money, it will be in circulation for another decade and probably much much longer. That would be a life-span of more than 20 years for his work.

If any of your photos, or posts, are particularly good, there is a chance that they may be around for a very very long time. If this were to happen, then I would wish to congratulate you for such a fine and lasting contribution.

[knifenut1013]

Send her a pm, she's on KF

[Lagrangian]

Hi knifenut1013,

Oh cool! Thanks! Will do.

Sincerely,
--Lagrangian

[HeavyHanded]

Thought this might be an interesting addition to the discussion.

http://www.smico.ca/sharpening-info-english.htm

Warning: A smooth steel is not a steel which has been passed on a grinding wheel or on a sanding machine !
- Warning: A smooth steel is not a steel which has been produced from a steel rod or a screwdriver handle!

- The raw material used for the steel shaft is a carbon-chrome vanadium steel
- The steels are covered on the surface with a thin layer of nickel followed by a hard-chrome layer.
- ISLER steels are hardened to 65 HRc (Rockwell hardness), which is considerably harder than the Rockwell hardness of the knife blades.

[David Martin]

HH, Thanks for the reference this seems to answer most of the questions presented. My ceramic stone is the Spyderco ultra Fine. DM

[Lagrangian]

Hi HeavyHanded,

Thanks for that link. Pretty interesting that they use a carbon-chrome vanadium steel. Also pretty interesting that it comes in several fine and finger textures. Even more interesting, is it nickel and chrome plated. From a Modern Marvels episode that I watched, I believe the nickel layer in chrome plating, is common, and in most cases is there as a very smooth surface. The smoothness of the nickle layer helps the chrome have a mirror finish (mostly for bling and show surfaces). Otherwise, they skip the nickle layer, and get a more mat chrome finish, which is not as shiny, but probably good enough in terms of corrosion and surface hardness.

btw, the chrome layer should be quite hard. I heard that for some (higher end?) M-16 rifles, they chrome the interior of the barrel for several reasons:
(1) Corrosion resistance (chrome, like aluminum, forms a tough transparent oxide layer that does not flake off, and so is considered corrosion resistant).
(2) Easier to clean-off or prevent build-up of carbon residue.
(3) Better wear resistance (because the chrome layer is very hard).

I may mis-remember some of the above, so I'll have to try to watch the episode again, and/or search the web or wikipedia. I'll let you know if I'm wrong. (Note: I just watched part of the episode again, and made corrections myself. Earlier I incorrectly stated that chrome would not stick to most metals directly, and so required an intermediate layer of nickle. This is incorrect. Chrome will stick directly. According to the Modern Marvels episode, the nickle is mainly there to provide a very smooth surface when a mirror finish is desired form the chrome layer.)

I believe I got the above info from this particular episode:
Modern Marvels: Chrome
The History Channel
Premiere Date: 03/02/2010

But I'm not too sure about 65 HRC being enough for the Isler steel.... At least _I think_ that would not be enough for Spyderco's ZDP-189 knives which are hardened to about 65 HRC already? This is according to Ankerson's tests where he had the HRC measured:
http://www.bladeforums.com/forums/sh...-5-8-quot-rope

I think most of the harder knives I've heard about are in the 62-63 HRC range, with ZDP-189 being exceptionally hard at 65 HRC. I wonder what range of hardness that Isler steel is designed to handle. Maybe an HRC in the low 60's is still okay for the Isler steel?

Sincerely,
--Lagrangian

[David Martin]

A company was chroming the inside of rifle barrels for accuracy, fowling and wear back in the mid 70's. These uses were well understood 40yrs. ago. DM

[Lagrangian]

A company was chroming the inside of rifle barrels for accuracy, fowling and wear back in the mid 70's. These uses were well understood 40yrs. ago. DM

Hi Dave Martin,

Thanks for your post. Certainly chrome plating has a very long history.
It's new and interesting to me that the chrome plating in the barrel also increases accuracy.

Sincerely,
--Lagrangian

[yuzuha]

Howdy all!

It is wonderful to see such in depth discussions continuing for so long. And I am quite flattered and overjoyed that some of you remember me (^-^)/

As for the pictures, alas the ISP that was hosting my web site up and quit hosting web sites without telling me. So, all those pics as well as my personal web pages (which were lovingly hand-crafted in 100% pure virgin asci-ii using notepad and arachnophilia) all vanished into the quantum foam. I will search on my old pc and see if I can find any of the photos and e-mail them to Lagrangian. BTW, that is an apt handle for a physics major... gotta love it! d(^-^)

Afraid I have had some health problems and wound up retired before my time, so I have not been doing much with knives or stones for the last couple of years but I still drop in KF and foodie forums once every few months to make sure the old crew is still having fun with such questions as "What exactly is a grit size, and how do you measure it even if the particles are not uniformly shaped," and other assorted mysteries of the universe.

As to the discussion, yes the white spiderco ceramic rods did seem to have similarly sized particles that looked something like shards of broken clam shells that had been tumbled a bit to round off the edges and then embedded in a matrix. As I recall the finish appeared to be a result of these rather large gently curved particles scraping and dispacing metal due to plastic flow, though occasionally marred by galling (looked like occasional bits of metal were torn from the smooth surface, then got caught between the stone and the metal and made occasional gouge streaks in an otherwise very smooth surface. Rather different from the "plowed field" look left by synthetic waterstones.

As I recall, I and several others guestimated the finest stone to be similar to the finish left by a 6k grit waterstone though that is a rough estimate (which if I remember correctly, Sal was comfortable with) though the surface looked entirely different at about 1,000x.

Great discussion! I will have to bookmark it and go read some of those fascinating links you've provided.

Later
Pam

[stitchawl]

Thought this might be an interesting addition to the discussion.

http://www.smico.ca/sharpening-info-english.htm

Warning: A smooth steel is not a steel which has been passed on a grinding wheel or on a sanding machine !
- Warning: A smooth steel is not a steel which has been produced from a steel rod or a screwdriver handle!

I find it interesting that they list this as some sort of 'warning.' I'd been using a ordinary steel rod (plain 'ol steel rod, not a manufactured Meatpackers or Butchers steel) that I picked up. Certainly not carbon-vanadiun steel coated with nickel then chromed. I used it with great results for many years before I switched to borocilicate glass for the task.

I suspect their 'warning' has more to do with sales of their own product. Theirs sell for $100 to $450 USD for full sized steels.
I think I paid $3 for mine. (It might have been $4.)


Stitchawl


Stitchawl

[HeavyHanded]

One thing I don't quite understand - chrome, when plated fairly thick, has an RC in the low 70s (if memory serves). Unless the chrome layer is just a flash chrome plating for corrosion resistance, you could use any carbon steel and get a good product. Why not use a tougher stainless?

I believe the difference in the Aus8 I observed was due to the higher level of polish I applied to the second 'steel' I whipped up from the Irwin drill bit. I reground the edge and did a ten pass test (with pics) and plan on running it out to 50 and then 100 passes. At ten passes I can see the beginning of the 'metal flow' from the apex - pretty sure I can make out the rounded shoulder from the boundary where its piling up a little back from the apex. Wanted to take a pic at 1000x but my bottle of cedar oil is all dried up

I feel like I'm in the wilderness a bit now - wouldn't surprise me in the least if smooth steels from different mfgs weren't producing different edges, then what happens as they age? In any event, I'll continue a bit till I get a feel for what's happening with the steels I have, and go from there. At some point I should include a write up for my Norton Crystalon stone as well, since its getting the job of baseline grind prep for all the samples.

[HeavyHanded]

I find it interesting that they list this as some sort of 'warning.' I'd been using a ordinary steel rod (plain 'ol steel rod, not a manufactured Meatpackers or Butchers steel) that I picked up. Certainly not carbon-vanadiun steel coated with nickel then chromed. I used it with great results for many years before I switched to borocilicate glass for the task.

I suspect their 'warning' has more to do with sales of their own product. Theirs sell for $100 to $450 USD for full sized steels.
I think I paid $3 for mine. (It might have been $4.)


Stitchawl


Stitchawl

^ this

Warning, don't even think about saving a ton of money by trying stuff out for yourself - WE'LL DO THE THINKING HERE.

[Lagrangian]

Hi yuzuha, Everyone,

yuzuha, thanks for your reply! It is great to hear from you, and wonderful to have your photos recovered.

I'm not sure what the best way is, to make sure the photos never disappear. It seems that bladeforums.com does not allow one to attach an image or file directly to one's post. So for now I'll try using imgur.com.

Below is a reconstruction of yuzuha's original post to www.foodieforums.com with the microscope images that she e-mailed me. Below that is her e-mail that includes the photos, plus some notes.

-------------------------------------------------------------------------
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Original Source:
http://www.foodieforums.com/vbulleti...3422#post23422

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Thread Topic: sharpening - where to start w/ a new knife?
Post Date: 12-13-2006, 09:22 PM

yuzuha
Super Foodie


Join Date: Mar 2005
Location: Nebraska
Posts: 416
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To start, I doubt the knife's angles are the same as the sharpmaker's (that 40-30 stuff seems more appropriate for outdoor knives and the like anyway), so you probably are just scraping the side of the bevel somewhere with it. Are you sure it has the same angles on both sides? Some double sided Japanese knives come with 70/30 or some other ratio bevels, and you can't do those on a Sharpmaker anyway (I only use my Sharpmaker on my Wushof's and Hecknel's... the 30 degree setting sharpens those up nicely, though I think they come with something closer to 22-25 degrees).

Generally, what I do is grab a 2k or 5k waterstone (depending on how sharp it seems in the first place) and sharpen it up a bit using the existing angles (you can rock the bevel on the stone, or sometimes go by visual clues in the water, to tell when the bevel is flat on the stone and just use whatever angle that is without caring what it is). If the edge seems too fragile, then I may drop back to the 1k and raise the spine just a smidgen and give it a slightly thicker bevel, but mostly I haven't had to do that.

Grouch, I have a table of waterstone grits (Shapton, old JIS standard and current JIS standard, Norton and DMT http://members.cox.net/~yuzuha/jisgrit1.html but bond makes a difference too since, while Norton says their 8k actually uses abrasive of a size equivalent to Shapton's 4k, everyone says it actually leaves a finish somewhere between the Shapton 5k and 8k), but it doesn't have sharpmaker rods in it... think that was CBWX34's spreadsheet.

Here is a photomicrograph of the Sharpmaker ultra-fine (comes with the medium and fine rods so I ordered a set of the ultra-fine too)

[Broken image link: http://members.cox.net/pihughes/superf25.jpg]


(25x objective, about 1,400x total). There are some larger and quite a few smaller (plus the tips of larger grains poking out of the matrix), but the majority of the larger grains appear to be around 2,000 grit JIS. But they are rounded and held tightly in a very dense matrix so they do not cut at all like a waterstone. Instead, they burnish like an orange stick on modelling clay, and, also like smoothing clay with a stick, the rods seem pull loose little balls of metal and smear them over the surface and leaves a finish that looks like this:

[Broken image link: http://members.cox.net/pihughes/surspyuf.jpg]


Leaves the burnished part nice and bright the surface isn't exactly smooth. Here is the same hunk of metal that I polished on a Naniwa 10k at a right angle to the sharpmaker that exposes the gouges made by the balls of metal the sharpmaker pulled up:

[Broken image link: http://members.cox.net/pihughes/surnansc.jpg]


Anyway, while the UF rods are probably 2k-3k grit abrasive, they do seem to leave a 5k-8k finish in the smooth burnished parts (the gouging/streaking makes them unsuitable for polishing the sides of blades but that should be less of a problem on a thin edge bevel).



Pam
--------
Sue ikki
mi hatenu yume no
hotsure kana---Choko
(This final scene, I
I will not see to the end.
My dream is fraying.)

-------------------------------------------------------------------------
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E-mail from yuzuha to Lagrangian with recovered photos:
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From: yuzuha
To: Lagrangian
Date: 2012/05/23
Subject: spyderco stone pics

Hi got your e-mail. I left a note on bladeforums (OMG I actually remembered my password for 6 years! Now if I could just remember why I went into the other room!) My ISP trashed my web space including my web site, and the pics I was hosting on it, but I did find some of the pictures on my old PC.

Superf25 is the spyderco super/ultra fine rod at, I’m guessing about 1,400x

Surspyuf is the .25" x 1.5" surface of a .25 x .5 x 1.5 inch block of stainless steel that I polished on the rod

Surnansc is the same surface polished on a 10k Naniawa super stone (not the chosera) at a right angle to the spiderco to show the gouges left when the steel galled under the spiderco.

A knife bevel is smaller and the steel is a trifle harder, and carbon steel is not as gummy so I doubt you’d see tear-outs like that unless you were actually trying to polish the side of the knife rather than just sharpening it. Even then it is microscopic. The side of the block was a hazy mirror finish after the spiderco and a bright mirror finish after the naniwa but the gouges were not noticeable to the naked eye.

Glad to see there are even more crazy people in the world that think about this stuff J

Now I am going to have to read all those links in that thread you guys created. Anyway… hope the pics help.
Later,
Pam


[ Images attached to this e-mail are now at imgur.com in the album:
https://imgur.com/a/KVdMk#0 ]

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Sincerely,
--Lagrangian
------------------------------------------------------------
"What grit sharpens the mind?"--Zen Sharpening Koan

[Lagrangian]

One thing I don't quite understand - chrome, when plated fairly thick, has an RC in the low 70s (if memory serves). Unless the chrome layer is just a flash chrome plating for corrosion resistance, you could use any carbon steel and get a good product. Why not use a tougher stainless?

Hi HeavyHanded,

I don't understand either. Maybe you could take microscope-images of the steel itself? (I mean images of the long round steeling steel.) That would give us some idea of what it's surface texture is like, and possibly give us ideas about what it is doing to the knife edge.

Sincerely,
--Lagrangian

[bluntcut]

Thus far the edge is getting in the way of learning about plastic-flow. Remove the edge, pressure will be less sensitive.


configA - large perpendicular force (to very small area, 90deg edge), we can quickly observe the drastic result.
configB - having a bevel, the result is more refine, observe lead/trail edge and bevel result.

Worth a try using a knife spine? I don't have high mag optic.