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Actually, FF-D2 is a steel. Friction Forging is a process.
-
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Friction Forged Blades : CATRA tests
- Thread starter Cliff Stamp
- Start date
Kohai999
Second Degree Cutter
- Joined
- Jul 15, 2003
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No, Keith, one would assume that the base elements are still there, therefore the FF would be a qualifier to differentiate between the Friction Forged steel, and the non-Friction forged steel, just like we say "cryo'd" fill in the blank steel. It is not a "new" steel, just a processed one.
Best Regards,
STeven Garsson
I'd put it like this. The friction forging process creates a new form of D2 on the edge portion of a blade. I'd call it Super D2 or something like that.
My highly biased thrift store scale relieves me from the need to invent and build a machine to do the cutting and sharpness measurement all in one package.
The accuracy of the scale is irrelevant to me because all knives tested on it are run to the same degree of dullness. The 35 lb stopping point is where the blades lose their bite in the rope. It’s also where they lose the ability to shave hair. It’s the degree of dullness where the knife will still cut but those who like a sharp knife will do something to bring it back to full cutting ability.
Wayne G
My highly biased thrift store scale relieves me from the need to invent and build a machine to do the cutting and sharpness measurement all in one package.
The accuracy of the scale is irrelevant to me because all knives tested on it are run to the same degree of dullness. The 35 lb stopping point is where the blades lose their bite in the rope. It’s also where they lose the ability to shave hair. It’s the degree of dullness where the knife will still cut but those who like a sharp knife will do something to bring it back to full cutting ability.
Wayne G
- Joined
- Jan 28, 2007
- Messages
- 2,155
The accuracy of the scale didn't really matter to me, I kinda figured that with the years of experience you've had performing the test, that you can probably feel when it hits 35 lbs with or without your scale, the scale is just an easy way to verify visually.
Phil,
I don't have the heat treatment information yet, and may not be able to get it for a week.
The measured hardness on the S90V was HRC 60.
Carl
You've got it right. However my accuracy increased by 5% on the scale. My three cutting tests varied an average of 10% judging the bite in the rope by feel alone. The average on the scale is 5%.
Wayne G
tnelson and cds4byu,
Thank you both very much for all the explanations. This place can be somewhat like a tar pit or honey trap, but this has been very, very interesting. I realize that you are not making any money by posting here (cost center, right?), and we all very much appreciate your time! I'm saving this thread so that I can re-read it a couple of times!
Thank you both very much for all the explanations. This place can be somewhat like a tar pit or honey trap, but this has been very, very interesting. I realize that you are not making any money by posting here (cost center, right?), and we all very much appreciate your time! I'm saving this thread so that I can re-read it a couple of times!
Sodak,
We hope the discussion and information have been helpful. We have certainly enjoyed the discussions with everyone. We'll continue to answer questions. If you have any questions after this thread ends, please email us.
Like Carl stated earlier: if your ever in Utah and want to see the process first hand, send us an email of give us a call.
TN
We hope the discussion and information have been helpful. We have certainly enjoyed the discussions with everyone. We'll continue to answer questions. If you have any questions after this thread ends, please email us.
Like Carl stated earlier: if your ever in Utah and want to see the process first hand, send us an email of give us a call.
TN
- Joined
- Jan 16, 2006
- Messages
- 386
Carl, thanks for the information. S90v performs at its best at 60/61. Much harder than that and it tends to be "chippy on a thin edge and softer and the edge rolls before it has a chance to wear to the carbides. This is based on my own tests on cutting rope. I use pretty much the same process that Wayne does with empassis on the feel factor. In any case I have a list of questions, but think I will save them untill I have a chance to try one of the FF knives one day. PHIL
Phil,
I look forward to having you have a chance to try out a blade. Check with Wayne, he's got some that you might be able to try out at Atlanta, if you're going to be there. (Notice how I make commitments for you, Wayne?) I'd like to get some comments from some more knife experts, so we can learn more about FFD2 performance.
Carl
------------------
It is not necessary to believe things in order to reason about them
It is not necessary to understand things in order to argue about them.
- P.A. Caron de Beaumarchais, French Author, 1732-1799
Wayne, Carl, Thanks for keeping contact on this thread, Im sure a lot of people would have given up entirely a long time ago.
I have to wonder. If you can get D-2 up to Rc 67, what could you do with steel that is optimized for this process? If I ever got my hands on a salt bath good enough to heat treat modern steel one of the first things Id do is try some CPM Rex 76 at Rc 69. Now, if steel like that can get to Rc 69 normally then do you think it would be possible for this process to bring that number up into the seventies? That would be awesome. Have you guys considered working with Crucible (or any other foundry) to try and make something that works ideally with Friction Forging?
Thanks for your time and keep up the good work.
I have to wonder. If you can get D-2 up to Rc 67, what could you do with steel that is optimized for this process? If I ever got my hands on a salt bath good enough to heat treat modern steel one of the first things Id do is try some CPM Rex 76 at Rc 69. Now, if steel like that can get to Rc 69 normally then do you think it would be possible for this process to bring that number up into the seventies? That would be awesome. Have you guys considered working with Crucible (or any other foundry) to try and make something that works ideally with Friction Forging?
Thanks for your time and keep up the good work.
Following is a FAQ that I received from Charles Allen about a week ago. The smoke has cleared enough here that it may be a good time to post it. It will be in two parts in order to fit the word limit of 15,000 characters. I've been told the DiamondBlade web page is getting close to finished so keep trying it.
Wayne G.
DiamondBlade FAQ
WHAT IS FRICTION FORGING®?
Friction Forging® is a localized forging process using high temperatures and high loads to deform and rapidly quench the steel in the zone that will eventually become the knife edge. Friction Forging® uses a specially designed tool made from Polycrystalline Cubic Boron Nitride (PCBN), a material second only to diamond in hardness. During forging, the PCBN tool penetrates the blade while rotating, which creates frictional heating and plasticizes (not melts) the steel. When the tool is fully engaged, it moves along the eventual blade edge, creating dynamic microstructure shearing and high forging pressures that produce excellent blade microstructures. The tools rotation speed, X & Y axis travel speed, Z loads, and blade temperatures are all computer controlled and monitored to insure consistency and repeatability for each blade.
The blade edge is brought above the transformation temperature by the rotating PCBN tool. As the tool moves, the knife-edge is continuously forged. The combination of thousands of pounds of downward forging force, tool rotation, and temperatures slightly above the transformation temperature produce dramatic reductions in austenite grain size. The grains are in effect torn apart and reduced in size by the combination of very high pressure and heat. Transmission Electron Micrographs (TEM) indicates that the grain size is reduced from 5-15 microns in typical heat-treated D2 knife steel down to 0.5 microns, a superfine nanograin size.
WHAT CHARACTERISTICS DO FRICTION FORGED® SUPER BLADES EXHIBIT?
A. First, lets define what a better blade is. A high performance Super blade has several differentiating characteristics:
1. The blade edge is 5-8 Rc points higher than the best heat-treated D2 blade steel.
2. The edge zone Martensite grain structures are 10x FINER than are those in conventionally best heat-treated D2 blade steel.
3. The blade STAYS SHARP SIGNIFICANTLY LONGER than other blades.
4. The edge is CORROSION PROOF and eliminates chemical etch dulling.
5. The blade is TOUGH and can withstand transverse loads effectivelythat is, you can flex the blade without the blade breaking or bending.
Why does one blade stay sharp longer than another? Materials that are harder and finer grained are proven to resist deformation due to abrasion better than a softer material. Therefore harder steels resist edge deformation (dulling) better than a softer blade. So this is one very key element in the equation, a harder blade will stay sharp longer than will a softer one. How do we measure hardness? Metallurgists and knife manufacturers typically use a couple of scales, one is called the Vickers scale and the other is known as the Rockwell C scale. Most knife users and manufacturers are more familiar with Rockwell so we will report our hardness values referencing the Rockwell C scale.
WHAT TESTING METHODS WERE USED TO DETERMINE PERFORMANCE?
First, lets set some ground rules to insure a fair comparison. A fair comparison mandates the blade shape must be EXACTLY the same between the blades being tested. This does not just apply to the overall shape; it means the cross-section geometry must be IDENTICAL from the cutting edge all the way to the spine and from one end of the test area to the other. We tested the Friction Forged® blades against blades of 13 different materials. All test blades were identical in overall and cross section edge geometry and thus the only difference was blade materialnot shape.
Materials tested against the Friction Forged D2 were 440C stainless steel, 154CM stainless steel, 5160 steel, D2 tool steel, AISI A1 and AISI 01 steel, 52100 steel, BG42, CPMS30V stainless steel, CPMS90V stainless steel, AUS8A stainless steel, 1095 steel and Talonite. All these materials were heat-treated, tempered and cryogenically treated with resulting RHc values between 58 and 61 depending on the steel (with the exception of Talonite).
Next, the comparisons must be made on the same day, ideally at the same time, using the same test media. Finally, the tests must be made hands-off to eliminate the human factor. Tests of cutting ping-pong balls, bottles of water, free-hanging rope, slabs of hanging meat, etc. are interesting and certainly illustrates one persons ability over anotherbut does it test one knife against another? Somewhat, but not very well. Those tests are subjective, biased, and not objective. This mandates we rely on precision computer-controlled and mechanical equipment to perform tests.
WHAT TYPE MACHINES OR EQUIPMENT WERE USED TO PERFORM TESTS?
The following test equipment descriptions explain the methods we use to determine sharpness, edge retention and longevity, and edge toughness.
1. CATRA Razor Edge Sharpness Tester (REST): This precision CNC test device is manufactured by the ISO standards approved Cutlery Association Testing Research Association (CATRA) in England. The machine actually measures how sharp an edge is by pushing a knife into calibrated silicone media until the blade edge penetrates to a certain depth, and measuring the maximum force required in Newtons (abbreviated N: 1 N is about ¼ pound). Our test results indicate that once a blade edge requires approximately 3.0 Ns to cut into the media, the edge will no longer shave and is no longer considered to be sharp. This method provides statistically testable numerical values.
2. Edge Retention Tester (ERT): This machine is CNC controlled and uses a reciprocating system that holds the test blade in place moving the blade in the XY axis. A system of air operated cylinders and mechanical locking mechanisms lowers and raises a ¾ inch diameter manila rope in the Z axis onto the blade under approximately 50 Ns of force (about 12 lbs.) The rope is securely held in place allowing the moving blade to cut the rope. After one stroke, the depth of cut is recorded in the process computer and graphed. The length of one blade stroke is preset and the same blade section (about 2.5 long) cuts the rope repeatedly. After a set number of cuts, the blade is removed and tested on the REST machine to measure sharpness in the blade zone where the rope was being cut. This sequence is repeated until the blade is no longer sharp as measured by consistent REST readings above 3.0 N.
3. Edge Strength Tester (EST): This is a mechanical machine that has a ¼ inch stainless steel rod secured in place at an 18-degree angle to a test blade lowered onto it. Force exerted on the razor sharp blade edge can be increased to 68 pounds. Evidence of edge chipping or deformation is noted and measured.
4. Flex Test: A test used by the American Bladesmith Society to determine blade toughness and edge strength. The test involves securing a blade in a vise at a point 1/3 the blade length from the tip. The blade is bent to breakage or a 90-degree angle and then the edge is inspected for cracking or chipping. This is our only hands-on test but leaves no doubt about a blades toughness and was thus used in our tests.
5. Corrosion Test: Test blades are coated with 100% Nitric Acid then immersed in salt water (fully saturated at 70 degrees F) for two weeks.
WHY DID YOU CHOOSE D2 TOOL STEEL TO FRICTION FORGE?
D2 is known for its toughness and has excellent chemical elements that will alloy and create a high performance blade.
DID YOU FRICTION FORGE OTHER STEELS AND WHAT WERE THE RESULTS?
Yes, we tried a few others but found various problems, especially with the particle metallurgy steels, that were complex and numerous. While these problems may eventually be worked out, we had so many other mechanical challenges to overcome at the outset that dealing with raw material problems just didnt make sense.
HOW LONG DID THE RESEARCH TEAM WORK ON FRICTION FORGING BLADES BEFORE YOU ANNOUNCED YOUR RESULTS?
The research spanned a period of 4 ½ years.
IS THIS TECHNOLOGY PATENTED?
Multiple US and Foreign patents held by various Universities and corporate entities protect Friction Stir Processing and PCBN tool manufacture. Solid State Processing of Hand-Held Knife Blades To Improve Blade Performance was filed by Allen, Charles E.; et.al, and is Patent Pending.
WHAT TESTS WERE CONDUCTED TO VERIFY PERFORMANCE?
More than 600 individual laboratory tests were conducted over four years, and thus, the raw data is simply too voluminous to report here. However, please see the section on Friction Forging and Engineering a Super Blade as data are reported there and discussed with graphs. You can also see Sorensen, C.D., Nelson, T.W., et.al. 2007. Friction Stir Processing of D2 Tool Steel For Enhanced Blade Performance, Friction Stir Welding And Processing IV, TMS Annual Meeting, Orlando, FL., ISBN 978-0-87339-661-5 for additional results. The pre-published paper and presentation can be found at the web site: www.byu.edu/groups/fsw
Wayne G.
DiamondBlade FAQ
WHAT IS FRICTION FORGING®?
Friction Forging® is a localized forging process using high temperatures and high loads to deform and rapidly quench the steel in the zone that will eventually become the knife edge. Friction Forging® uses a specially designed tool made from Polycrystalline Cubic Boron Nitride (PCBN), a material second only to diamond in hardness. During forging, the PCBN tool penetrates the blade while rotating, which creates frictional heating and plasticizes (not melts) the steel. When the tool is fully engaged, it moves along the eventual blade edge, creating dynamic microstructure shearing and high forging pressures that produce excellent blade microstructures. The tools rotation speed, X & Y axis travel speed, Z loads, and blade temperatures are all computer controlled and monitored to insure consistency and repeatability for each blade.
The blade edge is brought above the transformation temperature by the rotating PCBN tool. As the tool moves, the knife-edge is continuously forged. The combination of thousands of pounds of downward forging force, tool rotation, and temperatures slightly above the transformation temperature produce dramatic reductions in austenite grain size. The grains are in effect torn apart and reduced in size by the combination of very high pressure and heat. Transmission Electron Micrographs (TEM) indicates that the grain size is reduced from 5-15 microns in typical heat-treated D2 knife steel down to 0.5 microns, a superfine nanograin size.
WHAT CHARACTERISTICS DO FRICTION FORGED® SUPER BLADES EXHIBIT?
A. First, lets define what a better blade is. A high performance Super blade has several differentiating characteristics:
1. The blade edge is 5-8 Rc points higher than the best heat-treated D2 blade steel.
2. The edge zone Martensite grain structures are 10x FINER than are those in conventionally best heat-treated D2 blade steel.
3. The blade STAYS SHARP SIGNIFICANTLY LONGER than other blades.
4. The edge is CORROSION PROOF and eliminates chemical etch dulling.
5. The blade is TOUGH and can withstand transverse loads effectivelythat is, you can flex the blade without the blade breaking or bending.
Why does one blade stay sharp longer than another? Materials that are harder and finer grained are proven to resist deformation due to abrasion better than a softer material. Therefore harder steels resist edge deformation (dulling) better than a softer blade. So this is one very key element in the equation, a harder blade will stay sharp longer than will a softer one. How do we measure hardness? Metallurgists and knife manufacturers typically use a couple of scales, one is called the Vickers scale and the other is known as the Rockwell C scale. Most knife users and manufacturers are more familiar with Rockwell so we will report our hardness values referencing the Rockwell C scale.
WHAT TESTING METHODS WERE USED TO DETERMINE PERFORMANCE?
First, lets set some ground rules to insure a fair comparison. A fair comparison mandates the blade shape must be EXACTLY the same between the blades being tested. This does not just apply to the overall shape; it means the cross-section geometry must be IDENTICAL from the cutting edge all the way to the spine and from one end of the test area to the other. We tested the Friction Forged® blades against blades of 13 different materials. All test blades were identical in overall and cross section edge geometry and thus the only difference was blade materialnot shape.
Materials tested against the Friction Forged D2 were 440C stainless steel, 154CM stainless steel, 5160 steel, D2 tool steel, AISI A1 and AISI 01 steel, 52100 steel, BG42, CPMS30V stainless steel, CPMS90V stainless steel, AUS8A stainless steel, 1095 steel and Talonite. All these materials were heat-treated, tempered and cryogenically treated with resulting RHc values between 58 and 61 depending on the steel (with the exception of Talonite).
Next, the comparisons must be made on the same day, ideally at the same time, using the same test media. Finally, the tests must be made hands-off to eliminate the human factor. Tests of cutting ping-pong balls, bottles of water, free-hanging rope, slabs of hanging meat, etc. are interesting and certainly illustrates one persons ability over anotherbut does it test one knife against another? Somewhat, but not very well. Those tests are subjective, biased, and not objective. This mandates we rely on precision computer-controlled and mechanical equipment to perform tests.
WHAT TYPE MACHINES OR EQUIPMENT WERE USED TO PERFORM TESTS?
The following test equipment descriptions explain the methods we use to determine sharpness, edge retention and longevity, and edge toughness.
1. CATRA Razor Edge Sharpness Tester (REST): This precision CNC test device is manufactured by the ISO standards approved Cutlery Association Testing Research Association (CATRA) in England. The machine actually measures how sharp an edge is by pushing a knife into calibrated silicone media until the blade edge penetrates to a certain depth, and measuring the maximum force required in Newtons (abbreviated N: 1 N is about ¼ pound). Our test results indicate that once a blade edge requires approximately 3.0 Ns to cut into the media, the edge will no longer shave and is no longer considered to be sharp. This method provides statistically testable numerical values.
2. Edge Retention Tester (ERT): This machine is CNC controlled and uses a reciprocating system that holds the test blade in place moving the blade in the XY axis. A system of air operated cylinders and mechanical locking mechanisms lowers and raises a ¾ inch diameter manila rope in the Z axis onto the blade under approximately 50 Ns of force (about 12 lbs.) The rope is securely held in place allowing the moving blade to cut the rope. After one stroke, the depth of cut is recorded in the process computer and graphed. The length of one blade stroke is preset and the same blade section (about 2.5 long) cuts the rope repeatedly. After a set number of cuts, the blade is removed and tested on the REST machine to measure sharpness in the blade zone where the rope was being cut. This sequence is repeated until the blade is no longer sharp as measured by consistent REST readings above 3.0 N.
3. Edge Strength Tester (EST): This is a mechanical machine that has a ¼ inch stainless steel rod secured in place at an 18-degree angle to a test blade lowered onto it. Force exerted on the razor sharp blade edge can be increased to 68 pounds. Evidence of edge chipping or deformation is noted and measured.
4. Flex Test: A test used by the American Bladesmith Society to determine blade toughness and edge strength. The test involves securing a blade in a vise at a point 1/3 the blade length from the tip. The blade is bent to breakage or a 90-degree angle and then the edge is inspected for cracking or chipping. This is our only hands-on test but leaves no doubt about a blades toughness and was thus used in our tests.
5. Corrosion Test: Test blades are coated with 100% Nitric Acid then immersed in salt water (fully saturated at 70 degrees F) for two weeks.
WHY DID YOU CHOOSE D2 TOOL STEEL TO FRICTION FORGE?
D2 is known for its toughness and has excellent chemical elements that will alloy and create a high performance blade.
DID YOU FRICTION FORGE OTHER STEELS AND WHAT WERE THE RESULTS?
Yes, we tried a few others but found various problems, especially with the particle metallurgy steels, that were complex and numerous. While these problems may eventually be worked out, we had so many other mechanical challenges to overcome at the outset that dealing with raw material problems just didnt make sense.
HOW LONG DID THE RESEARCH TEAM WORK ON FRICTION FORGING BLADES BEFORE YOU ANNOUNCED YOUR RESULTS?
The research spanned a period of 4 ½ years.
IS THIS TECHNOLOGY PATENTED?
Multiple US and Foreign patents held by various Universities and corporate entities protect Friction Stir Processing and PCBN tool manufacture. Solid State Processing of Hand-Held Knife Blades To Improve Blade Performance was filed by Allen, Charles E.; et.al, and is Patent Pending.
WHAT TESTS WERE CONDUCTED TO VERIFY PERFORMANCE?
More than 600 individual laboratory tests were conducted over four years, and thus, the raw data is simply too voluminous to report here. However, please see the section on Friction Forging and Engineering a Super Blade as data are reported there and discussed with graphs. You can also see Sorensen, C.D., Nelson, T.W., et.al. 2007. Friction Stir Processing of D2 Tool Steel For Enhanced Blade Performance, Friction Stir Welding And Processing IV, TMS Annual Meeting, Orlando, FL., ISBN 978-0-87339-661-5 for additional results. The pre-published paper and presentation can be found at the web site: www.byu.edu/groups/fsw
Cliff Stamp
BANNED
- Joined
- Oct 5, 1998
- Messages
- 17,562
This is not a correct summary of what I said. I said that when you plotted the graph the primary way as shown in your pdf it both increased the noise significantly, even worse coupled it now with both axes which makes all linear problems nonlinear (NEVER DO THAT), and the data simple becomes undefined as there is far too much scatter. If you did a simple montecarlo simulation you would see that which blade was superior was actually undefined.
Ok, just wanted to clear up a few issues, then you can continue with whatever lies you want completely ignored. The last plot I showed was the RAW data, it was not manipulated nor any calcuations performed on it. It was the data just as it came off the machine. The data that they showed was not RAW. So if you want to put the above criticism on anyone it is on them.
That data is indeed modeled by the same equation, I have shown it before. What I contended was the level of precision noted. As I have stated clearly in the past there is no requirement on precision for scientific work, however if you do state a level of precision you must have the means to obtain it and getting a 5% cut ratio when the variance is as high and the model nonlinear is very difficult as I noted in the above. I would think impossible actually because of the systematic differences.
CATRA machines are not new, they were used in germany in the 20-30's. As I have said in the past I would not use machines to model human behavior as no one would because it would be a baised sample. I have clearly shown in the above two examples of knives which shown how biased CATRA results are to the point of being meaningless in regards to infering about human results. All of these factual data is of course ignored.
Why don't they model the data, probably because they can't. The model I proposed fits their data perfectly and allows the calculation of specific cut ratios and their uncertainties, which I have shown with several sets, both on CATRA and the different machine here. It will also fit human hand data, it even works on dental scrapers. It does all this because it is based on the PHYSICS of blunting which is the same in all cases. What changes is the magnitude of the parameters is all.
Such statements do little because you are introducing opinion into a math discussion. I defined why such plots are not used because of math problems they induce, it isn't a preference as I like steak over chicken. You don't make linear problems nonlinear, you don't couple uncertainties to both axes, you don't magnify errors, etc. . The reason you don't do this is because it becomes more complex to analyze the problem and the results get distorted and uncertain. Note as well all nonlinear problems have multiple solutions so you have to be careful to note you have the absolute minimum not just a local one, this is where you have to use montecarlo simulations.
You can only do that if the model supports it. This makes a number of assumptions about the underlying data which are not true in this case. You don't average a nonlinear function and then compare. If you want to see just how absurd the results of this can be I can generate some graphs and show you how you both lose information and distort the performance horribly.
The math will not support you there either because the noise is too high.
Yes, as I showed, there is a performance increase of about 30-50% of the type specified, at the angle given with the noted heat treatment of S90V with the given sharpening method cutting the specific media by a specific method. Note how much weaker this statement is compared to the origional ones - any scientific comparison will be of this type. Of course what this statement implies is that the advantage would not be the same if any of the conditions were not met which is going to be true.
Given that the nature of the process is one that refines the ausgrain and the carbide structure, I would suggest that you test push cutting at lower angles as the steel should outperform S90V very strongly there. This would seem to be the true advantage of the steel. I would combine this with sharpening on nondiamond abrasives to show that the steel is superior there because of the lack of a large volume fraction of vanadium carbides.
Building a maching to test human edge retention is also nonsense and no sensible bio-engineer would do that for the reasons I have described in the above. The results are going to be meaningless. I have again cited two examples of blades which show that method to be flawed, one of them shows that it is in fact absurd. Use the machines to get the physical properties, corrosion resistance, wear resistance (of the multitude of types), and check edge stability directly (over a range of angles).
It actually takes quite a long time to do that, I think Landes has noted months to do edge stability testing on just one steel. So if you are doing comparisons it will take awhile to get real supporting data in a material sense. You of course couple this with sensible testing proceedures from your test team and you use the required methods to produce UNBIASED results. If you are not clear what these are then just ask and I will tell you.
-Cliff
WHY MENTION CORROSION PROOF? LOTS OF BLADE STEELS ARE STAINLESS.
True, but none with a 65-68 RHc cutting edge and not D2. A stainless edge is important, as it will resist chemical edge degradation that has the same dulling effect on a knife-edge, as does abrasion deformation.
IS THE ENTIRE BLADE D2 OR HAVE YOU WELDED OR SOMEHOW JOINED ANOTHER PIECE OF DIFFERENT METAL TO THE KNIFE BODY?
The entire blade is D2.
D2 WILL STAIN AND RUST, WHY IS THERE A STAINLESS CORROSION PROOF ZONE WHERE THE FRICTION FORGING HAS OCCURRED?
This is a bit complex. When D2 is made in the mill, the steel is alloyed with several elements such as Carbon, Vanadium, Chromium, Manganese, Molybdenum, Nickel, and Silicon at prescribed percentage ranges. When quenched under normal conditions, a percentage of the Carbon combines with the Chromium and Vanadium to form Metal Carbides. When Chromium is locked up in Carbides, this reduces the amount of Chromium available in the ferrite. When the Chromium in the ferrite is reduced below 12%, the steel is unable to prevent staining and rusting. This is why D2 is known as a high carbon, stain resistant but not stainless steel.
During the Friction Forging® process, some of the Chromium is freed up to go back into the ferrite. Under the heat and pressure of the spinning PCBN tool, the steel becomes plasticized sufficiently to go above transformation (eutectoid) temperature. At this temperature, Chromium carbides begin to dissolve. Both Chromium and Carbon are freed up and go into solution in the austenite when steel is in the Friction Forged® plasticized state.
Once completed, the Friction Forged zone is quenched rapidly by the surrounding steel which is cold, i.e. room temperature. This rapid quench is sufficiently fast as to minimize any carbide formation during cooling. This essentially freezes in the Chromium and Carbon into the very fine Martensite grain structures. The free Chromium in the martensite makes the Friction Forged zone Stainless. The extra carbon in solution enables higher hardness than in traditional process D2.
SO YOU HAVE CREATED A DIFFERENT KIND OF ALLOY?
No, we have not changed the percentage of the elements so legally it is still D2. However we have re-distributed the way the elements combine at the molecular levelthus the corrosion proof edge and extra bump in hardness.
IVE ALWAYS THOUGHT ROCKWELL VALUES ABOVE 61 OR 62 WOULD PRODUCE A BRITTLE EDGE PRONE TO CHIPPING AND LOW TRANSVERSE LOAD STRENGTH. WITH FRICTION FORGED EDGES AT 65-68 ROCKWELL, WHAT RESULTS WERE REALIZED WITH FLEX TEST?
We bent 10 test blades with edge hardness values between 65-68 RHc to over 90 degrees with no edge cracking or chipping. This was on a blade designed to the test standard blade geometry as described by the American Bladesmith Society test. No Friction Forged® blade constructed to these geometries failed the test.
WERE THESE TESTS WITNESSED BY PEOPLE OTHER THAN THOSE ON THE RESEARCH TEAM OR DIAMONDBLADE EMPLOYEES?
Yes, about 30 people outside the team and employees have witnessed this test.
ARE YOU WILLING TO PUBLICLY DEMONSTRATE THE FRICTION FORGED BLADE STYLE THAT PASSED THESE TESTS?
Yes.
WHAT EASY TO OBSERVE AND UNDERSTAND TESTS COULD WE WATCH THAT WILL INDICATE HOW HIGH QUALITY THE FRICTION FORGED BLADES ARE?
Well, how about this:
1. Cut 500 pieces of ¾ manila rope on the ERT CNC machine and have a CATRA REST reading of less than 3.0 Newtons; translation: will still shave.
2. Chop through a 2x4 10 times, no edge damage and will still have a CATRA REST of less than 3.0 and will still shave.
3. With one stroke, cut free-hanging rope 1.0 in diameter 6 inches or less from bottom at least 10 times and will still have CATRA reading of less than 3.0 and will still shave.
4. Bend to 90 degrees or more with no edge chip, crack, or breakage of any kind.
5. Coat blade with 100% Nitric Acid to test for corrosion proof edge. Immerse in saturated saltwater solution for two weeks.
These tests are well above those required for passing the ABS Journeyman test and thus should provide you a good indication of high performance. Ideally, we would prefer to test along side another non-Friction Forged blade made by another maker of any material of their choosing but both blades should be of the same geometry and of course each blade will be subjected to each of the tests listed above.
REGARDING SHARPENING
One of the greatest exaggerations ever told goes like this: Knife Buyer: How does this knife hold an edge? Knife Salesman: Great. Knife Buyer: Is it hard to sharpen? Knife Salesman: Nope, it holds a great edge and is easy to re-sharpen.
Are your red lights starting to blink? They should, because from a pure physics standpoint, a material cant be both at the same time. Its either soft, easy to dull, and easy to re-sharpen, or at the extreme end (where our blades are), very hard and very difficult to dull, and consequently they take more time to re-sharpen.
SO, THESE SUPER BLADES HARD TO SHARPEN?
Compared to other knife blades? Yes they are, however by using an aluminum oxide 320 grit Fine India stone by Norton, you can put a beautiful razor edge back on this material without a great deal more effort than experienced with a normal premium grade steel. You can also use the diamond sharpeners but they will not leave as nice of an edge. We also recommend a few strokes on a polishing strop at the end. The Arkansas stones are just not quite hard enough to cut this material and are not recommended.
WHY IS ONE KNIFE EASIER TO SHARPEN THAN ANOTHER?
A couple of reasons. One is geometry. Thick blades are harder to sharpen than a thinner blade because you have to grind away so much material. The second is directly proportional to the blade edge hardness. High hardness means it is more resistant to abrasion and dulling. That is, the harder blade will always stay sharp a lot longer than will a softer blade. Consequently, a harder blade is more resistant to grinding and honingsharpening. Because a normal knife blade edge has a hardness value of 58 to 61 Rockwell (RHc), and the DiamondBlade knives have edge hardness values from 65 to 68, they will resist dulling much more effectively than will other knivesthey stay sharp longertests indicate about 10 times longer than standard best quality D2 bladesand will take more time to re-sharpen once they do eventually lose their shaving sharp edge.
WILL THE DIAMONDBLADE FACTORY RE-SHARPEN THE KNIVES AND WHAT IS THE CHARGE?
We will re-sharpen and completely recondition your DiamondBlade knife at no charge other than a nominal shipping and handling fee of $15.
HOW SHOULD I CARE FOR THE DIAMONDBLADE KNIVES?
These blades are precision instruments that required multiple manufacturing and handcraftsmanship processes to build. They deserve to be treated as you would a fine gun.
HOW SHOULD I TREAT THE BLADE STEEL?
Because the Friction Forging® process was performed on D2 steel, a stain resistant but not classed as a stainless steel, it is important you keep the blade clean and oiled or the area above the Friction Forged® zone will stain and even develop light rust. We also recommend you remove the knives from their sheaths and coat them with oil for long-term storage.
WHAT IS THE SHINY ZONE ALONG THE EDGE?
This is the undeniable trademark of a true Friction Forged® blade. The area approximately .375 inch above the edge has all been forged and is very hard. It is so hard, that when we use our ceramic peening process on the blade, the Friction Forged® zone cannot be peened and comes out bright and shiny.
True, but none with a 65-68 RHc cutting edge and not D2. A stainless edge is important, as it will resist chemical edge degradation that has the same dulling effect on a knife-edge, as does abrasion deformation.
IS THE ENTIRE BLADE D2 OR HAVE YOU WELDED OR SOMEHOW JOINED ANOTHER PIECE OF DIFFERENT METAL TO THE KNIFE BODY?
The entire blade is D2.
D2 WILL STAIN AND RUST, WHY IS THERE A STAINLESS CORROSION PROOF ZONE WHERE THE FRICTION FORGING HAS OCCURRED?
This is a bit complex. When D2 is made in the mill, the steel is alloyed with several elements such as Carbon, Vanadium, Chromium, Manganese, Molybdenum, Nickel, and Silicon at prescribed percentage ranges. When quenched under normal conditions, a percentage of the Carbon combines with the Chromium and Vanadium to form Metal Carbides. When Chromium is locked up in Carbides, this reduces the amount of Chromium available in the ferrite. When the Chromium in the ferrite is reduced below 12%, the steel is unable to prevent staining and rusting. This is why D2 is known as a high carbon, stain resistant but not stainless steel.
During the Friction Forging® process, some of the Chromium is freed up to go back into the ferrite. Under the heat and pressure of the spinning PCBN tool, the steel becomes plasticized sufficiently to go above transformation (eutectoid) temperature. At this temperature, Chromium carbides begin to dissolve. Both Chromium and Carbon are freed up and go into solution in the austenite when steel is in the Friction Forged® plasticized state.
Once completed, the Friction Forged zone is quenched rapidly by the surrounding steel which is cold, i.e. room temperature. This rapid quench is sufficiently fast as to minimize any carbide formation during cooling. This essentially freezes in the Chromium and Carbon into the very fine Martensite grain structures. The free Chromium in the martensite makes the Friction Forged zone Stainless. The extra carbon in solution enables higher hardness than in traditional process D2.
SO YOU HAVE CREATED A DIFFERENT KIND OF ALLOY?
No, we have not changed the percentage of the elements so legally it is still D2. However we have re-distributed the way the elements combine at the molecular levelthus the corrosion proof edge and extra bump in hardness.
IVE ALWAYS THOUGHT ROCKWELL VALUES ABOVE 61 OR 62 WOULD PRODUCE A BRITTLE EDGE PRONE TO CHIPPING AND LOW TRANSVERSE LOAD STRENGTH. WITH FRICTION FORGED EDGES AT 65-68 ROCKWELL, WHAT RESULTS WERE REALIZED WITH FLEX TEST?
We bent 10 test blades with edge hardness values between 65-68 RHc to over 90 degrees with no edge cracking or chipping. This was on a blade designed to the test standard blade geometry as described by the American Bladesmith Society test. No Friction Forged® blade constructed to these geometries failed the test.
WERE THESE TESTS WITNESSED BY PEOPLE OTHER THAN THOSE ON THE RESEARCH TEAM OR DIAMONDBLADE EMPLOYEES?
Yes, about 30 people outside the team and employees have witnessed this test.
ARE YOU WILLING TO PUBLICLY DEMONSTRATE THE FRICTION FORGED BLADE STYLE THAT PASSED THESE TESTS?
Yes.
WHAT EASY TO OBSERVE AND UNDERSTAND TESTS COULD WE WATCH THAT WILL INDICATE HOW HIGH QUALITY THE FRICTION FORGED BLADES ARE?
Well, how about this:
1. Cut 500 pieces of ¾ manila rope on the ERT CNC machine and have a CATRA REST reading of less than 3.0 Newtons; translation: will still shave.
2. Chop through a 2x4 10 times, no edge damage and will still have a CATRA REST of less than 3.0 and will still shave.
3. With one stroke, cut free-hanging rope 1.0 in diameter 6 inches or less from bottom at least 10 times and will still have CATRA reading of less than 3.0 and will still shave.
4. Bend to 90 degrees or more with no edge chip, crack, or breakage of any kind.
5. Coat blade with 100% Nitric Acid to test for corrosion proof edge. Immerse in saturated saltwater solution for two weeks.
These tests are well above those required for passing the ABS Journeyman test and thus should provide you a good indication of high performance. Ideally, we would prefer to test along side another non-Friction Forged blade made by another maker of any material of their choosing but both blades should be of the same geometry and of course each blade will be subjected to each of the tests listed above.
REGARDING SHARPENING
One of the greatest exaggerations ever told goes like this: Knife Buyer: How does this knife hold an edge? Knife Salesman: Great. Knife Buyer: Is it hard to sharpen? Knife Salesman: Nope, it holds a great edge and is easy to re-sharpen.
Are your red lights starting to blink? They should, because from a pure physics standpoint, a material cant be both at the same time. Its either soft, easy to dull, and easy to re-sharpen, or at the extreme end (where our blades are), very hard and very difficult to dull, and consequently they take more time to re-sharpen.
SO, THESE SUPER BLADES HARD TO SHARPEN?
Compared to other knife blades? Yes they are, however by using an aluminum oxide 320 grit Fine India stone by Norton, you can put a beautiful razor edge back on this material without a great deal more effort than experienced with a normal premium grade steel. You can also use the diamond sharpeners but they will not leave as nice of an edge. We also recommend a few strokes on a polishing strop at the end. The Arkansas stones are just not quite hard enough to cut this material and are not recommended.
WHY IS ONE KNIFE EASIER TO SHARPEN THAN ANOTHER?
A couple of reasons. One is geometry. Thick blades are harder to sharpen than a thinner blade because you have to grind away so much material. The second is directly proportional to the blade edge hardness. High hardness means it is more resistant to abrasion and dulling. That is, the harder blade will always stay sharp a lot longer than will a softer blade. Consequently, a harder blade is more resistant to grinding and honingsharpening. Because a normal knife blade edge has a hardness value of 58 to 61 Rockwell (RHc), and the DiamondBlade knives have edge hardness values from 65 to 68, they will resist dulling much more effectively than will other knivesthey stay sharp longertests indicate about 10 times longer than standard best quality D2 bladesand will take more time to re-sharpen once they do eventually lose their shaving sharp edge.
WILL THE DIAMONDBLADE FACTORY RE-SHARPEN THE KNIVES AND WHAT IS THE CHARGE?
We will re-sharpen and completely recondition your DiamondBlade knife at no charge other than a nominal shipping and handling fee of $15.
HOW SHOULD I CARE FOR THE DIAMONDBLADE KNIVES?
These blades are precision instruments that required multiple manufacturing and handcraftsmanship processes to build. They deserve to be treated as you would a fine gun.
HOW SHOULD I TREAT THE BLADE STEEL?
Because the Friction Forging® process was performed on D2 steel, a stain resistant but not classed as a stainless steel, it is important you keep the blade clean and oiled or the area above the Friction Forged® zone will stain and even develop light rust. We also recommend you remove the knives from their sheaths and coat them with oil for long-term storage.
WHAT IS THE SHINY ZONE ALONG THE EDGE?
This is the undeniable trademark of a true Friction Forged® blade. The area approximately .375 inch above the edge has all been forged and is very hard. It is so hard, that when we use our ceramic peening process on the blade, the Friction Forged® zone cannot be peened and comes out bright and shiny.
- Joined
- Jan 6, 2007
- Messages
- 911
I know nothing of steels so would friction forging work with titanium?
(And I actually know that titanium is not a steel...)
(And I actually know that titanium is not a steel...)
- Joined
- Nov 27, 2003
- Messages
- 1,727
Has the mythical packed edge become a reality?
Hey Wayne, are there plans to produce folders from this steel? This crossover of technologies sounds like a real innovation.- Joined
- Apr 3, 2004
- Messages
- 3,536
How would this stuff be to sharpen? Queen's D2 at 60 is a bear to reprofile, how hard is this?
Cliff Stamp
BANNED
- Joined
- Oct 5, 1998
- Messages
- 17,562
If grindability is an issue at all then the geometry and/or steel is poorly optomized for the knife. In the case of the Queen's I would suspect the edges are overthickened and/or very obtuse. In any case get a 200 grit silicon carbide waterstone and you can ignore grindability anyway.
-Cliff
-Cliff
- Joined
- Apr 3, 2004
- Messages
- 3,536
You reworded my question and sidestepped it. I reprofile about everything as it is, so go from there, as I asked... how hard to reprofile?
cliff: perhaps you could explain what you mean about grindability. I take it you are referring to the need to grind the finished blade if its design isn't suited to its intended task? (like the zdp cyclone?). Considering its hardness I would imagine that using a waterstone it would take more passes to sharpen than regular 60HRC D2 even though the FFD2 has much smaller carbides. Care to elaborate?