S30V 1K SiC and UF abraded surfaces

bluntcut said:
OK, I can see why you picked 1). Assuming ceramic would just slide/ride on top of densely populated carbide dome top.

More details needed for this hypothetical. 15% VC volume/density and carbide are 1/4 to 3/4 diameter deep embedded. Because of gaps, there will be impacts/collisions.

LOL - I sort of want to know, would anyone would give 2) some percent. If not, why expect magical outcome when trying to shape(#2) apex decorated VC with sintered ceramic. For submicron wide apex 15dps, the chance of #1 for decorated VC is super low since lateral impact will be too high for small embedded footing, thus #3 outcome should be expected. Again, we/knut are talking about try to produce a high uniformity submicron apex width and flatness. If diamond plates (150 to 0.025 micron mesh) are free, then yeah all users would benefit because outcome/result would be more deterministic/predictable than sintered ceramic. well, neither free nor sub 3um plate avail :rolleyes:
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Carbides buried 1/2 and less more likely to be removed, but how? If the surface is invincible, they aren't being plowed.
I can see very shallow buried carbides coming out, depending on bond strength.
They can be grabbed/pulled, wedged, or fractured out.
With an invincible surface, carbides more than 1/2 buried would have to be fractured out.
 
cemented(by cobalt or martensite layer/glue) carbides would dislodge when lateral/sheer impact exceed footing/adhesion & leverage strength.
 
BluntCut MetalWorks BluntCut MetalWorks , here's a practical question I'm trying to figure out. Setting aside the ever-popular and never ending discussions around ceramics for a minute. :-)

Question is on what SiC grits to use with super steels (in my case, my "super steels" are the more moderates vanadium content, like M390, S30v, S35vn, not ones like s90v/s110v).

So I get it that at super coarse levels, like even Crystolon fine, you're just coarsely plowing through the steel no matter what you use, so likely there's not a big difference in outcomes between SiC or diamonds.

But...at what ANSI grit rating with SiC abrasive do you hit the limits where, to get an optimal edge, you would recommend switching diamonds? Do you think the 1K Sharp Pebble for example (grit rating used is still TBD--I've emailed them but I'm betting on JIS) can properly abrade high carbides and would you recommend using it?
 
Let's use minimal setup. One 2um diameter VC cemented 1/3 deep(binded by 0.5um cobalt hole boundary) onto invincible surface. Now ram M/F/UF into this VC .
 
When you say "hole boundary", is that the gap between cobalt and carbide? or is that the thickness of cobalt between surface and carbide.
 
Sorry, once saw, can't un-see, unless sort of labotomy ;)

For steels with any measurable-usage-affect of VC, I recommend edge trailing on clean 1K SiC stone (SharpPebble) or lightly glazed(some use to simulate 1K) Crystolon F, then refine with the 3K or EE diamond.

Did you buy that $10 3K diamond plate? See & Feel for sure :D

maximus83 said:
BluntCut MetalWorks BluntCut MetalWorks , here's a practical question I'm trying to figure out. Setting aside the ever-popular and never ending discussions around ceramics for a minute. :)

Question is on what SiC grits to use with super steels (in my case, my "super steels" are the more moderates vanadium content, like M390, S30v, S35vn, not ones like s90v/s110v).

So I get it that at super coarse levels, like even Crystolon fine, you're just coarsely plowing through the steel no matter what you use, so likely there's not a big difference in outcomes between SiC or diamonds.

But...at what ANSI grit rating with SiC abrasive do you hit the limits where, to get an optimal edge, you would recommend switching diamonds? Do you think the 1K Sharp Pebble for example (grit rating used is still TBD--I've emailed them but I'm betting on JIS) can properly abrade high carbides and would you recommend using it?
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bluntcut said:
For steels with any measurable-usage-affect of VC, I recommend edge trailing on clean 1K SiC stone (SharpPebble) or lightly glazed(some use to simulate 1K) Crystolon F, then refine with the 3K or EE diamond.
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Ok this helps. Follow-ups:

  • Can you summarize why edge TRAILING, what that is giving you here?
  • What do you mean by "glazed" Crystolon?
  • Don't have anything in 3K range, but do have a DMT EEF. So I can experiment going straight from coarse SiC to EEF to finish.
 
bluntcut said:
Edge Retention(ER) is open ended in both quali & quanti. In world actual uses, apex width probably 10+um wide, so both diamond & ceramic probably has almost identical ER line. Delineation becomes more pronounce when comparison go toward extreme parameters (apex width, carbide volume, hardness). There isn't much a doubt that diamond is the right abrasive to shape/sharpening Ceramic & WC blades, where M,F,UF would just do damage (DQ in ER race). I wouldn't want a surgeon to use a scalpel in s30v with edge sharpened solely by ceramic - since any hole/dip in apex could tear capillaries... but for rope cutting - diamond & ceramic probably has similar ER performance (diamond probably has advantage only at peak 5% of sharpeness).
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So are you saying that it is not detrimental to either the edge or the stone to sharpen steels featuring high hardness carbides (VC) on ceramics? (As come with sharpmaker)

I have heard arguments that ceramics will not properly cut the VC, and the VC will burnish the surface of the ceramics, particularly nonfriable like the SM rods.
 
Right.
jpm2 said:
Right, so I guess it depends on strength, toughness, elasticity, etc of the binder/glue.
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Worth mention again. From my data/observation a carbide decorated on apex, when fracture - the hole/chunk often 1.5 to 5 times of carbide diameter. So for the case above, ram 1+um diamond tip at it, would also dislodge this embedded carbide. Micrographs of EE 10V (plain & etched) - show missing carbide holes, albeit much less than sintered ceramic. Exactly why I recommend 0.25 to 0.1um diamond (est cutting tip be around 1/10 abrasive diameter), which would slowly cut/abrade VC to avoid impact carbide with force can dislodge them.
 
maximus83 said:
I had a conversation with another sharpening SME here in the forum a week or so ago, and they said they are surprised, using ceramics in a refining role with high carbide steels, it's not supposed to work, but it does. That has been my experience as well.

It seems like what we're saying here is that from the best we can tell, carbide tear-out occurs when you use a ceramic, even lightly at the end of sharpening to refine or micro. But...for ordinary knife uses, that doesn't really impact the durability of your edge. It would only make a difference in specialized applications where you're going for maximum sharpness; in that case, use diamonds.

If that's the point being made, you can see why folks like Cliff, and some of the sharpening pros right here in BF, continue to use ceramics on high carbides. It's conceivable that for normal EDU knife tasks, the average knife owner could do everything they ever needed to do sharpening-wise with a Norton combi Crystolon, a cheap ceramic F or UF hone, and a strop. And this would work perfectly fine even on their high carbide steels. True, they'll be giving up the carbides in that last little bit of edge. But if a carbide falls off a knife edge, and no one ever sees it or feels the difference, did it really happen? :)
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But if most of the carbides are tearing out the edge by using ceramics, what is point of having a high VC blade steel?
 
Inline...
maximus83 said:
Ok this helps. Follow-ups:

  • Can you summarize why edge TRAILING, what that is giving you here? SiC is very friable, esp against carbides (CrC, VC, WC,NbC, etc..), so edge-lead would round the edge.
  • What do you mean by "glazed" Crystolon? A thin layer of slurry (fractured SiC much finer than F)
  • Don't have anything in 3K range, but do have a DMT EEF. So I can experiment going straight from coarse SiC to EEF to finish. Better result with E then EE. Dude - spend $10 on that cheap 3K.
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Glazing in stones is not a layer of slurry. It's the result of blunted abrasive on the surface of the stone, leading to a glossy surface and burnishing of the work piece.
 
OK thanks, will experiment with this approach and post back when I get a chance. Interested to compare and see if finishing with diamonds, versus finishing with UF ceramic, makes a difference that *I* can notice, without having access to microscopes and other gear to measure the results at a fine scale.

Also gonna have to learn to do edge-trailing strokes better on an aggressive/coarse stone. This is harder than you think, for some of us who are weekend warrior sharpeners. My technique isn't that great on this yet, last time I tried it I horked an edge that I had just spent an hour working on. :cool:
 
Lapedog said:
But if most of the carbides are tearing out the edge by using ceramics, what is point of having a high VC blade steel?
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Exactly. But what I was saying there is, Bluntcut earlier had made it sound like yes the carbides are gone, but it's not really impacting EDU knife users that much. So I was speculating that maybe this sort of "sure it happens at some level but it's not making any real world difference" perspective is what's driving some experienced, smart sharpening folks to continue using ceramics in a limited role with high carbides. But rather than speculate, I'd prefer if those folks just spoke up for themselves here. :-) Obviously Cliff can't, he's banned.
 
maximus83 said:
Exactly. But what I was saying there is, Bluntcut earlier had made it sound like yes the carbides are gone, but it's not really impacting EDU knife users that much. So I was speculating that maybe this sort of "sure it happens at some level but it's not making any real world difference" perspective is what's driving some experienced, smart sharpening folks to continue using ceramics in a limited role with high carbides. But rather than speculate, I'd prefer if those folks just spoke up for themselves here. :) Obviously Cliff can't, he's banned.
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As I understand it, even Cliff is not 100% on this point once the abrasive tip size drops down to the size of the carbides.

After all, what is the point of high carbide steel if it doesn't resist abrasion better than lo carbide steel?

I've mentioned this before, but if high Vanadium carbide steel had carbides the size of the ones in D2, there would be zero confusion on this issue - you wouldn't even be able to put a working edge on it with anything but diamond or CbN. Only the fact the carbides are nearly small enough to the size of a good working edge width allows you to get a good edge with ordinary abrasives - until the relative size of abrasive to carbide ='s out.
 
Hey BluntCut MetalWorks BluntCut MetalWorks , so here in your thread we're talking about using SiC at the coarse end of spectrum with high carbides, and it seems like consensus is it doesn't matter because you're just "plowing steel" when you're working in the 300 to 400 grit grange. Which makes sense.

So extending that logic: In coarse sharpening of high carbides, why not just use a harder 300 to 400 grit AlOX stone, some would prefer Norton India, but myself, I'd prefer Arctic Fox in this range? To me, the AF gives a nicer finish than SiC, doesn't wear down as fast thus less frequent flattening, and can be used as water stones, all advantages in convenience. So the question is, if you're just "steel plowing" at a coarse grit, why not use AlOx rather than SiC? (I'm sure this question has been discussed before, but now I can't find anything detailed about this).
 
For given SiC & AlO have same binder strength, AlO particle is more durable due to higher fracture strength (lower friability than SiC). Less loose/fractured/broken down AlO grit mean less self-inflicted-binder-plowing, hence surface stay flat longer and duller grit to produce the *bold text* result. Remember I stated in big-font+bold 'Sharp' above, SiC is better. Sure both can glaze but SiC does that less than AlO.

Steel swarf also plays a role in plowing binder away, so increase wear resistant = less wear = less swarf + grit dulled by carbide, lead to more burnishing and if/when inadvertently apexed, then damaged&fractures chunks are much larger than plowing with less burnishing.

Dope AlO surface with loose AlO or SiC grit would help release stone fresh grit. Both can benefit but AlO would benefit from doping more than SiC because of condition above.

I do use AF (fine side of field stone) on steel with less than 5% carbide volume (e.g. 3V, niolox, aebl) - while don't apex or pseudo apex with light pressure to minimize edge crumbling. I've at least 4 cheap coarse grit AlO stones for high pressure plow but recently they are collecting dust. I prefer using slow speed 220 ceramic belt or SiC or sometime 400grit diamond.

maximus83 said:
Hey BluntCut MetalWorks BluntCut MetalWorks , so here in your thread we're talking about using SiC at the coarse end of spectrum with high carbides, and it seems like consensus is it doesn't matter because you're just "plowing steel" when you're working in the 300 to 400 grit grange. Which makes sense.

So extending that logic: In coarse sharpening of high carbides, why not just use a harder 300 to 400 grit AlOX stone, some would prefer Norton India, but myself, I'd prefer Arctic Fox in this range? To me, the AF gives a nicer finish than SiC, doesn't wear down as fast thus less frequent flattening, and can be used as water stones, all advantages in convenience. So the question is, if you're just "steel plowing" at a coarse grit, why not use AlOx rather than SiC? (I'm sure this question has been discussed before, but now I can't find anything detailed about this).
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