Recommendation? Idea about plate quenching?

Status
Not open for further replies.

Jason Ward

DISHONEST RIP OFF ARTIST
Joined
Feb 12, 2022
Messages
54
I'm curious if anyone out there or knows anyone else that CNCs a negative of a blade design with say aluminum plate quenching and if there is any differences given that even well foil wrapped; air is pretty good at insulting so I've been told. I've thought about trying it but my ... Frank opinion is that it wouldn't be much different if anything maybe with straightening not performance (well geometry,ya I get it). Unless you plate quenched like 1095 which even then(theoretical of course). Opinions?

Also my first post here! Really haven't spent much time on here yet but the names Jason, not new to the internet and I'm glad to be here. Discuss some science with smart people finally! 😳😜


Cheers,
 
Last edited:
Welcome Jason.

Plate quenching is not so much for quench speed as it is to lessen the total time of transformation. It also greatly lessens warp issues. The steels plate quenched would harden if just suspended in the foil packet in air. The physical method of a plate quench is it absorbs the radiated energy of the packet, and this shortens the time to cool to room temp.
The minute amount of gap between the plates and the packet, and trapped air in the packet are insignificant.
 
Welcome Jason.

Plate quenching is not so much for quench speed as it is to lessen the total time of transformation. It also greatly lessens warp issues. The steels plate quenched would harden if just suspended in the foil packet in air. The physical method of a plate quench is it absorbs the radiated energy of the packet, and this shortens the time to cool to room temp.
The minute amount of gap between the plates and the packet, and trapped air in the packet are insignificant.
Thanks! Good to be here. I do agree with everything that you said. *But* Has anyone actually tested it scientifically? Larrin/KSN is a no. I've asked. I don't know anyone else who actually would and yes I'm aware I'm being VERY picky here I agree that it would probably only be for straightening there's nothing about science that I know that would .. be worth talking about but I have never seen anyone ACTUALLY test it. I guess I will! Do I think it's a waste of time. Yup. Got the equipment to do it though. I've seen people use hydro presses on foil to flatten the air out and I always asked myself . Why? Okay I get air is actually much better at insulation than most* people think but I also understand the metallurgy part -- So I came to the same conclusion in my head but why not test it. I got 150$ to blow on aluminum (🙄). I'm pretty sure (we're all 99.9% until it's that .01%) we all know the results but if I see anything unique it'll be noted here. The least exciting post of the day ladies and gentlemen 😅
 
The bugaboo will be in getting perfect alignment of the top and bottom negative plates and the blade. The only way to do that would require removal of the blade from the foil packet ... which defeats the point of the foil packet.

If doing it on carbon steel blades, it would work, if done as a die setup where the bottom recess is deeper than the blade and the top plate seats in the recess.

One point I didn't add in my first reply is that many of us use a fixed bottom plate and a floating top plate. This allows the best alignment for taper and bevel as possible. My setup uses a single point pressure on the top plate, allowing it to seat against the packet/blade as snugly as possible. I get no warp or twist at all with that setup.
 
Interesting thanks I have not received my evenheat yet everything is being vac furnaced but that's pretty much exactly how I was going to do it. My only question and it's rather pointless but by fixed bottom you mean it's affixed to a surface with a mechanical or chemical bond? If so my question would be the why as I can't think of anything off the top of my head but I'm sure I either misread or understood something.

I intended to take the existing CNC model(Yes, I CNC cut 🙄) and just totally remove the foil from the equation figuring that if I'm exact enough on the tolerances (I'm using aerospace tolerances, so essentially ±0.0005), I have the equipment to do it so that should be a good enough seal for oxygen why mess with added variables. If I'm forgetting something or if you have any other ideas or thoughts, they're much welcome and much appreciated! 👍 I'm human it's very easy to forget something very important lol.
 
Interesting thanks I have not received my evenheat yet everything is being vac furnaced but that's pretty much exactly how I was going to do it. My only question and it's rather pointless but by fixed bottom you mean it's affixed to a surface with a mechanical or chemical bond? If so my question would be the why as I can't think of anything off the top of my head but I'm sure I either misread or understood something.

I intended to take the existing CNC model(Yes, I CNC cut 🙄) and just totally remove the foil from the equation figuring that if I'm exact enough on the tolerances (I'm using aerospace tolerances, so essentially ±0.0005), I have the equipment to do it so that should be a good enough seal for oxygen why mess with added variables. If I'm forgetting something or if you have any other ideas or thoughts, they're much welcome and much appreciated! 👍 I'm human it's very easy to forget something very important lol.
How are you keeping your blades oxygen free in the oven and then transferring to the plates oxygen free if you're not using foil? And you're going to have lots of issues if you're machining your plates to the same nominal dimension as your blade blanks because of thermal expansion. As a back-of-hand rule of thumb, steel expands about 1 thou per inch per 100˚F (actually slightly less but it's close enough). So when you take your 8" knife out of the oven at 2000˚F, it will be about 20 thou per inch longer than when it was cold. Over an 8" knife that is about 1/8" growth! And that's not to mention the distortion and change in geometry that inevitably arises during heat treat. After cooling your geometry won't be the same as before to within 5 thou everywhere, let alone half a thou.
 
By fixed lower quench plate, I mean that it sits flat on the bench top surface and does not move or tilt. It is not mechanically bonded. I can slide it forward and back as needed or change it for a different plate if needed.
The upper quench plate is placed on the foil blade packet and pressure is applied to the top plate just in front of the ricasso area. This allows the plate to tilt minutely in any direction needed to sit as snugly to the packet as possible. The main tilt is along the distal taper of the blade, which prevents warping. It also tilts a bit toward the edge. Best results are when you place the tip end of the packet at the end of the quench plates.
 
Why you simple not cut end of foil , take blade out and clamp between aluminium plates so you have that full contact ???
 
By fixed lower quench plate, I mean that it sits flat on the bench top surface and does not move or tilt. It is not mechanically bonded. I can slide it forward and back as needed or change it for a different plate if needed.
The upper quench plate is placed on the foil blade packet and pressure is applied to the top plate just in front of the ricasso area. This allows the plate to tilt minutely in any direction needed to sit as snugly to the packet as possible. The main tilt is along the distal taper of the blade, which prevents warping. It also tilts a bit toward the edge. Best results are when you place the tip end of the packet at the end of the quench plates.
A lot of gymnastics there ..............
Don t you think that best result are when you HT piece of steel and then make knife from that ?
 
The bugaboo will be in getting perfect alignment of the top and bottom negative plates and the blade. The only way to do that would require removal of the blade from the foil packet ... which defeats the point of the foil packet.

If doing it on carbon steel blades, it would work, if done as a die setup where the bottom recess is deeper than the blade and the top plate seats in the recess.

One point I didn't add in my first reply is that many of us use a fixed bottom plate and a floating top plate. This allows the best alignment for taper and bevel as possible. My setup uses a single point pressure on the top plate, allowing it to seat against the packet/blade as snugly as possible. I get no warp or twist at all with that setup.
Why ? What would happen in that five seconds ? It not defeat anything if you ask me .
Watch first 2 minute of this video . ..............
 
You're all right calm down Jesus. Thank you C CallumRD1 for pointing out my failure point in thinking. I'll have to figure that out. (Nitrogen room purge is possible). I calculate for the thermal expansion in datasheet guys I have a materials science background - I do understand physics and chemistry just a little bit lol. And N Natlek you're also correct in that time not making a significant difference but it IS making one. I'll post the results of my study when it's complete. This is science. I come from knife steel nerds and that's what got me into knife making. My day job is PC network cyber security systems. I don't do the internet because of this BS and I can't escape it even with knife makers. And actually N Natlek it doesn't matter when you quench you don't want to do it and then grind that is as I'm sure you know or seem to, stupid and a huge waste of your time. Now you don't fully finish a knife either but go as thin as possible with the given alloy.
How are you keeping your blades oxygen free in the oven and then transferring to the plates oxygen free if you're not using foil? And you're going to have lots of issues if you're machining your plates to the same nominal dimension as your blade blanks because of thermal expansion. As a back-of-hand rule of thumb, steel expands about 1 thou per inch per 100˚F (actually slightly less but it's close enough). So when you take your 8" knife out of the oven at 2000˚F, it will be about 20 thou per inch longer than when it was cold. Over an 8" knife that is about 1/8" growth! And that's not to mention the distortion and change in geometry that inevitably arises during heat treat. After cooling your geometry won't be the same as before to within 5 thou everywhere, let alone half a thou.

Why ? What would happen in that five seconds ? It not defeat anything if you ask me .
Watch first 2 minute of this video . ..............
 
By fixed lower quench plate, I mean that it sits flat on the bench top surface and does not move or tilt. It is not mechanically bonded. I can slide it forward and back as needed or change it for a different plate if needed.
The upper quench plate is placed on the foil blade packet and pressure is applied to the top plate just in front of the ricasso area. This allows the plate to tilt minutely in any direction needed to sit as snugly to the packet as possible. The main tilt is along the distal taper of the blade, which prevents warping. It also tilts a bit toward the edge. Best results are when you place the tip end of the packet at the end of the quench plates.
That's how I was taught. Thank you. Seriously. I know you can't know what I do.
 
The bugaboo will be in getting perfect alignment of the top and bottom negative plates and the blade. The only way to do that would require removal of the blade from the foil packet ... which defeats the point of the foil packet.

If doing it on carbon steel blades, it would work, if done as a die setup where the bottom recess is deeper than the blade and the top plate seats in the recess.

One point I didn't add in my first reply is that many of us use a fixed bottom plate and a floating top plate. This allows the best alignment for taper and bevel as possible. My setup uses a single point pressure on the top plate, allowing it to seat against the packet/blade as snugly as possible. I get no warp or twist at all with that setup.
Stacy , I understand what he wants to do and It can be done that way , but I don't understand how he will check the result ? As far as I know, you can t measure Rockwell hardness on tapered surface / bevels / ?
I am missing something here ?
 
Sounds like a lot of work, especially if you have multiple blade profiles or if they aren't all exactly identical.
What problem would this solve, exactly?

Plunging the blade into cryo would then stress it more, and no longer held by the plates. IME, correcting warps between plate quench and cryo/sub-zero is futile, as you don't know what the blade will do during the cold treatment.

Hardness can be less-precisely checked with hardness chisels, but you'll have to make some over 64Rc.
 
Sounds like a lot of work, especially if you have multiple blade profiles or if they aren't all exactly identical.
What problem would this solve, exactly?

Plunging the blade into cryo would then stress it more, and no longer held by the plates. IME, correcting warps between plate quench and cryo/sub-zero is futile, as you don't know what the blade will do during the cold treatment.

Hardness can be less-precisely checked with hardness chisels, but you'll have to make some over 64Rc.
No idea it's called a science experiment for a reason LoL. I have a CATRA edge retention tester. I obviously have a Rockwell tester. I honestly agree with what you said 100%. It's one of 50,000 ideas I have but actually have the equipment to scientifically test.
 
Stacy , I understand what he wants to do and It can be done that way , but I don't understand how he will check the result ? As far as I know, you can t measure Rockwell hardness on tapered surface / bevels / ?
I am missing something here ?
A taper is a flat surface. 😋 It's not a "bevel". I know you just slapped yourself for not thinking about that. It's okay we're all human. I forgot about the 5 seconds in atomosphere!
 
Sounds like a lot of work, especially if you have multiple blade profiles or if they aren't all exactly identical.
What problem would this solve, exactly?

Plunging the blade into cryo would then stress it more, and no longer held by the plates. IME, correcting warps between plate quench and cryo/sub-zero is futile, as you don't know what the blade will do during the cold treatment.

Hardness can be less-precisely checked with hardness chisels, but you'll have to make some over 64Rc.
Sorry I read this twice. This would eliminate any warping but it's caused by mainly simple thermal expansion - to which sub 350F to -320F (okay a good delta) most of the thermal expansion is done and as far as I know (which isn't much 😅) warping isn't going to be as big of an issue AND YES I GET IM SAYING THIS ON AN EVEN SMALLER ISSUE but I need hard science here. KSN only goes so far. Not far enough for me.
 
A taper is a flat surface. 😋 It's not a "bevel". I know you just slapped yourself for not thinking about that. It's okay we're all human. I forgot about the 5 seconds in atomosphere!
I will slap myself again , twice this time :) Taper is still flat surface of course , but to measure hardness with Rockwell tester you need two parallel FLAT surface not tapered one ?
 
Jason - I am mat sci/chem e … so I get where you are coming from. If you can do the experiment, why not?

Don’t worry about the banter- I don’t have to tell you that every forum has its share of “personalities” and differing opinions.

My question would be one of consistency. Let’s say you do the experiment and you see a difference that is worth chasing for. Can you the devise a setup where you consistently get a 2000 degree piece of metal positioned to a tolerance on the order of a couple mils in a short enough time?
 
Ok, for fun it is. Looking forward to what you learn.

I'm an engineer of sorts who works in the sciences. We often have to prioritize what we experiment with because we're usually trying to solve a particular problem in a time-frame on a budget
 
Status
Not open for further replies.
Back
Top