Recommendation? Idea about plate quenching?

[Jason Ward]

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 ?

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

daizee Yes most of the research like this as you know is paid for by grants and is done specifically for a time frame result. That's science but. Ya I'll update the post when they decide to deliver my evenheat! And ya true N Natlek but how hard is it to make it a parallel flat surface? Trigonometry exists for a reason

 

[Jason Ward]

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?

In a short enough timeframe depends on what timeframe you're sticking to me. This was just an idea that I know has never been tried so. I do stuff when I want LoL - I think that would be the reason most of us decided to get into this so not say by the end of this week but. End of the month probably around then. And I'm really not expecting any differences but if there is something to chase then yes I have the equipment to do so outside of changing designs that quickly. It's going to require a few pieces of aluminum but it's cheap enough right now. It's 3d laser scanned and CNCd at a friend's shop. I could be missing something else I'm not thinking about - comments and criticism are welcome! Without it I don't learn.

 

[CallumRD1]

I'm still curious what your plan is for dealing with thermal expansion. How are you going to mill a negative into the plate that simultaneously fits both a hot and cold blade? Maybe I'm missing an elegant solution to the problem but I'm not currently seeing a way past it.

 

[Jason Ward]

I'm still curious what your plan is for dealing with thermal expansion. How are you going to mill a negative into the plate that simultaneously fits both a hot and cold blade? Maybe I'm missing an elegant solution to the problem but I'm not currently seeing a way past it.

Powdered aluminum is what I was thinking. Not going to be easy I never said that lol.

 

[Jason Ward]

Powdered aluminum is what I was thinking. Not going to be easy I never said that lol.

Nickle powder? May have to think about this one. I originally planned to just use multiple plates but I do want to at least get the datasheet expansion numbers calcd in for the highest minimal air gaps but ya I get it's not exact so. I'm thinking about something that would melt but not cause a fucking mess

 

[Jason Ward]

Graphite/al2o3 powder is the best I can think of right now. I'm up for any others!

 

[daizee]

why not go with a positive relief instead of worrying about thermal expansion? Or just tolerate the plates not closing entirely. Does the assembly have to be enclosed around the perimeter to be a worthwhile experiment?

I squeeze a pair of plates vertically/laterally against the largest flat surfaces of my plate-quenched blades (trickier with tapered tangs, but doable). I do it upright to attempt to reduce warping from blades bending under their own weight (plus foil packet weight). Obviously there's an air gap between the plates themselves. I've taken to pulling air through the gap on the blade side with the shop-vac, where there's minimal contact there if I grind before heat. That way blades are less likely to warp (cooler) coming out of the packet. So it's a plate/air combo of sorts. I don't do it often enough to claim any statistical improvement, but it "feels" like it's helping.

 

[Cushing H.]

In a short enough timeframe depends on what timeframe you're sticking to me. This was just an idea that I know has never been tried so. I do stuff when I want LoL - I think that would be the reason most of us decided to get into this so not say by the end of this week but. End of the month probably around then. And I'm really not expecting any differences but if there is something to chase then yes I have the equipment to do so outside of changing designs that quickly. It's going to require a few pieces of aluminum but it's cheap enough right now. It's 3d laser scanned and CNCd at a friend's shop. I could be missing something else I'm not thinking about - comments and criticism are welcome! Without it I don't learn.

Hi Jason. I think my question did not come through cleanly enough. First - I am not saying dont do this experiment - I think you should. My question was not about can you do this experiment in some certain amount of time. If this works - my question is about repeatability from knife to knife in the long run. Given the tolerances you are trying to hit - is it possible to devise a method (or equipment) so that when you (or someone else) is processing many knives, and have to deal with a very hot piece of metal being transitioned quickly from the oven into the (very tight fitting) cavity in the quench plates - it can be done consistency and repeatably so that all future knives have the same positive result? If you can accomplish that, then you have something that many others can benefit from.

(you cant tell that I have spent a lot of my career in design and process quality, can you????

 

[CallumRD1]

Graphite/al2o3 powder is the best I can think of right now. I'm up for any others!

I think you're moving in the right direction with that train of thought with a few caveats. The coefficient of thermal conductivity of aluminum oxide is quite poor. Graphite powder is much better but has a relatively low density (~2/3 that of aluminum) and slightly lower specific heat capacity so the heat capacity per unit volume of the of the powder surrounding your blade is much lower than solid aluminum. Also, by using a powder you lose one of the primary benefits of quench plates: keeping the blank from warping as it cools.

 

[Jason Ward]

Hi Jason. I think my question did not come through cleanly enough. First - I am not saying dont do this experiment - I think you should. My question was not about can you do this experiment in some certain amount of time. If this works - my question is about repeatability from knife to knife in the long run. Given the tolerances you are trying to hit - is it possible to devise a method (or equipment) so that when you (or someone else) is processing many knives, and have to deal with a very hot piece of metal being transitioned quickly from the oven into the (very tight fitting) cavity in the quench plates - it can be done consistency and repeatably so that all future knives have the same positive result? If you can accomplish that, then you have something that many others can benefit from.

(you cant tell that I have spent a lot of my career in design and process quality, can you????

Hahaha yessir I can and I can't say that I have that all figured out yet. Everything I know about science says that this is going to probably not be a very significant difference if any but that's why we gotta test real world environment.

I don't see this being able to be scaled to a mass production technique that financially/logistically makes sense but if something odd happens with hardenability/microstructure then I guess I'll just report my findings and let people make their own decisions. Is it a lot of work for a relatively stupid idea - most definitely but it's a question that being me, it's going to bother the hell out of me until I can say I know it one way or the other. I honestly didn't even think about scalability yet cause I'm not expecting it to make any logical sense to do but again. I don't know anyone who has actually tried it, I got the equipment necessary and also time to get the results just for my own interest. If it ends up being beneficial I'm not the kind of person that would even THINK about trying to patent it. I'll post it on here and y'all can fight over the IP rights I can't stand civil court with it's proponderance of the evidence biased judge bs and oh gee how could I forget the quarter of a mil legal fees just to do that.

Jason will pass

Plus I think that research should benefit anyone who wants to further that research and leave as little legal bs for anyone trying to do that. I'm not saying I'm being extremely smart there it's not going to make me rich but that's also not the idea behind it whatsoever.

That sounded awfully pompous - I am not saying I'm not a human being that loves money LMAO I'm just saying this is not. The area where that's a concern of mine?

I sure as shit ain't some saint

 

[Cushing H.]

Jason - I've always felt the best reason to do an experiment is because "you feel like it" (well .... unless your boss refuses to pay for it..... )

 

[Jason Ward]

I think you're moving in the right direction with that train of thought with a few caveats. The coefficient of thermal conductivity of aluminum oxide is quite poor. Graphite powder is much better but has a relatively low density (~2/3 that of aluminum) and slightly lower specific heat capacity so the heat capacity per unit volume of the of the powder surrounding your blade is much lower than solid aluminum. Also, by using a powder you lose one of the primary benefits of quench plates: keeping the blank from warping as it cools.

Yeah I'm trying to figure that out there's some ideal material what will take a bit of research with the temps were dealing with. I didn't actually know that about aluminum oxide so thank you! I can't say I've done any actual research yet I'll spend some time tonight trying to figure out the best overall material. Sodium crossed my mind but how. It's a question that I don't know the exact answer to yet amongst many things

 

[Jason Ward]

Jason - I've always felt the best reason to do an experiment is because "you feel like it" (well .... unless your boss refuses to pay for it..... )

Hahaha it's nice being your own boss eh pity it doesn't really work out in real life

 

[Justin W]

Probably two sintered metal plates saturated in mercury would solve your thermal expansion and conduction issues, while still being stiff enough to reduce warpage. The sintered plate is not cheap, but available in many alloys, particle sizes and densities, and is machinable. The mercury could also be a disaster.

Good luck!

 

[CallumRD1]

Probably two sintered metal plates saturated in mercury would solve your thermal expansion and conduction issues, while still being stiff enough to reduce warpage. The sintered plate is not cheap, but available in many alloys, particle sizes and densities, and is machinable. The mercury could also be a disaster.

Good luck!

Mercury boils at about 350°C…

 

[Jason Ward]

Mercury boils at about 350°C…

That's why I was thinking sodium/lithium but that's an even bigger disaster

 

[Natlek]

I think you're moving in the right direction with that train of thought with a few caveats. The coefficient of thermal conductivity of aluminum oxide is quite poor. Graphite powder is much better but has a relatively low density (~2/3 that of aluminum) and slightly lower specific heat capacity so the heat capacity per unit volume of the of the powder surrounding your blade is much lower than solid aluminum. Also, by using a powder you lose one of the primary benefits of quench plates: keeping the blank from warping as it cools.

Before I even start with test like this I would do simple test .Two exactly same blade wrapped in foil .One i will quench in ordinary way between Al plates other one /cut foil and take blade out / quench in salt or in oil .And then search for difference . I still don t know how I would measured hardness on already finished bevels because that is most important part of blade to search/measure for difference
Quenching in oil should probably give little more hardness then quenching in Al plates , but it will be all over the steel so it can not be problem in test for comparison .

 

[Natlek]

why not go with a positive relief instead of worrying about thermal expansion? Or just tolerate the plates not closing entirely. Does the assembly have to be enclosed around the perimeter to be a worthwhile experiment?

I squeeze a pair of plates vertically/laterally against the largest flat surfaces of my plate-quenched blades (trickier with tapered tangs, but doable). I do it upright to attempt to reduce warping from blades bending under their own weight (plus foil packet weight). Obviously there's an air gap between the plates themselves. I've taken to pulling air through the gap on the blade side with the shop-vac, where there's minimal contact there if I grind before heat. That way blades are less likely to warp (cooler) coming out of the packet. So it's a plate/air combo of sorts. I don't do it often enough to claim any statistical improvement, but it "feels" like it's helping.

Maybe to heat plates before quenching to compensate thermal expansion in steel ? Expansion from heat in metals is predictable ?

 

[Natlek]

daizee Yes most of the research like this as you know is paid for by grants and is done specifically for a time frame result. That's science but. Ya I'll update the post when they decide to deliver my evenheat! And ya true N Natlek but how hard is it to make it a parallel flat surface? Trigonometry exists for a reason

Ok , why you don t test first one blade quenched in ordinary way between Al plates ? Almost all air trapped in foil would be on bevels side .So I guess the temperature transfer from steel to AL plates will be slower there ? And then measure hardness on spine or ricasso / flat and parallel part of steel / and use trigonometry to measure hardness on bevels?

 

[Jason Ward]

Ok , why you don t test first one blade quenched in ordinary way between Al plates ? Almost all air trapped in foil would be on bevels side .So I guess the temperature transfer from steel to AL plates will be slower there ? And then measure hardness on spine or ricasso / flat and parallel part of steel / and use trigonometry to measure hardness on bevels?

Well. Partially correct. Most steels I use are air hardening. Can you do canola or Parks a real oil quechant - well technically yes also like I could technically forge 3+ % carbon. it's just not something that is a smart idea. And not every alloy responds the same. It's called hardenability as I'm guessing you know lol. And ya I already got the hardness data from a vac furnace and cryo as I wait evenheat. 3/10 weeks You're correct that it's going to be harder where it's thinner on the bevels and most tests are done on the spine that's exactly what I want to test. I want to see what numbers match more uh. Shitty heat treats used in production knives compared to a shitty HT just with some help from physics. yep exactly what I planned on doing thanks for the assistance with this guys. That goes for everyone.

Pretty much everything I know what to do except I need to find something to expand and contract that acts as filler. Has anyone added nitrogen to an evenheat? Atmospheric pressure not 5 bar. Me thinks it's possible so why not? Additional easier test that again afaik nobody has tried it.

I do also have an XRF spectrometer that is far from the ideal machine to get an alloy measurement on steel. Mine can actually measure anything heavier than Mg so it's possible to kinda math out a generality but it can't see carbon etc that has to be mathed out and isn't well. Accurate enough for me.

I guess I should mention that if anyone wants to send me something to test I can run a full CATRA edge retention test, I don't have a Charpy izod tester I'm..lazy and I feel I can make that easier than buying one. Uhh. Anything else that I could help anyone out with that I can't think about. I'm a pretty chill dude until you stick me around stupid people . And of course there's no costs for testing except for shipping and if you want a CATRA test done.. well. The paper isn't exactly cheap so I won't ask for money but I am far from rich (admittedly okay I have friends that actually are asinine rich) which is how I have access to what I do.

Anyone want some science done? This you could actually put me on a schedule for and I'd only take money for CATRA test card. You can offer - I'll politely decline. I don't do this for money I do it for knowledge.

Making knives also I really don't do for profit business. I'm a nobody except for the people who absolutely can't stand me because I don't have a college degree. (KSN folk). I have more questions than the average person and I learn this shit really quick cause I'm an autodidact. I have found that to anger people that have the same knowledge but +300k in student debt. Starting to sound cocky which isn't intentional at all I'm just honestly letting you guys know more about me that is actually pertinent information. I'm an open book - anyone have a question for me just ask. I'll answer literally anything. **As honestly as I can, some stuff I just don't know. Gee how about that!** Please don't take my text the wrong way or read into anything that I didn't say exactly. Not trying to be a drama fuck just opening up if anyone wants to know me.