Titanium chef knife?

[Larrin]

Boker made Cera-Titan knives which got their wear resistance from included Titanium Carbides, and they also added some Silver to enhance ductility. It took me awhile to tumble to the fact that the TiC inclusions were very hard and required Diamonds or Cubic Boron Nitride to make a decent edge. The wear resistance is great.View attachment 1762598

That makes sense given the marketing of this stuff. Not particularly exciting.

 

[Rockwelledge75]

That makes sense given the marketing of this stuff. Not particularly exciting.

Hey Larrin do you know what if any differences would exist with in a steels properties if already preformed carbides were added to the mix and sintered together as oppose to the carbides forming naturally in the steel as a result of whatever given formulation?

 

[Larrin]

Hey Larrin do you know what if any differences would exist with in a steels properties if already preformed carbides were added to the mix and sintered together as oppose to the carbides forming naturally in the steel as a result of whatever given formulation?

Agglomeration is very common for a larger effective carbide size, and it is typically done to have an increased carbide fraction. In general I wouldn't say that is necessarily desirable. For example people already complain about sharpening CPM-15V, Maxamet, and Rex 121.

 

[kwackster]

For anyone interested in some real world experiences:

Forever Titanium Hybride knife GHT-16 (Cera-Titan)

When writing my review of the Forever SC-16WB ceramic knife (http://www.bladeforums.com/forums/showthread.php/1206014-Forever-SC-16WB-ceramic-knife?highlight=forever+ceramic+knife) i found that the same company also produces titanium hybrid knives. According to their website these blades consist...

www.bladeforums.com

https://www.bladeforums.com/threads/forever-diamond-titanium-knives.1508000/#post-18897603

 

[Mecha]

Do you recall which titanium alloy can reach hrc 65?

Most steels are quite brittle at this hrc too, or atleast they were before the powder metallurgy process came along and started producing steels like 4v which can get that hard while maintaining a decent toughness. Which makes me wonder are there any powder metal titanium alloys that increase the toughness of otherwise brittle hard alloys? If not, than what's the hardest you've seen a Ti alloy heat treated to where it still maintains toughness that would be acceptable for a knife, 57-58 perhaps?

This is all so interesting to me, I consider my self an amateur metallurgist and know my steels pretty well but learning about titanium has sparked insightful energy in me

I don't recall the alloy, as it was probably a one-off. The number of various ti alloys that are or were mass-produced and have an ASTM grade is quite low, but there are many oddball ti alloys that were made in small batches over the years, mostly several decades ago. While steel metallurgy has continued to advance, titanium metallurgical advancements have been stalling, and sort of repeating themselves for quite some time now.

The hardest ones I tested that weren't roached-out were upper 50s, and beyond that I was getting negative results as a blade. Generally speaking, with titanium alloys it's the crystalline phase and microstructure that matters, a lot more than hardness. "Alpha Prime" Titanium martensite doesn't want to yield, and it takes a lot to break it. It's flexible and tough, but isn't malleable and doesn't want to gall (edge doesn't get easily smooshed with use, which has always been the problem with ti) which helps immensely with edge-holding.

The hardness and other characteristics after creating "Alpha Prime" titanium martensite is going to be largely determined by the alloying elements, and trying to get it to read higher on a Rockwell hardness test isn't necessarily going to increase blade performance (though of course some things do follow along with hardness). The basic main point is that in this phase, it doesn't take a set or yield, therefore the fine-grained edge is going to go through whatever's being cut without issues, provided it's not highly abrasive. That's the mechanism by which a hardened ti alloy blade works.

The general consensus is that as a knife it functions a lot like a nice basic high carbon steel.

If you guys want to see a nice chef knife, made out of actual titanium alloy, here is a recent one made by BladeMan . I only heat treated it, he did everything else:

Titanium Kitchen Knife Prototype

Just finished this Kitchen Knife Prototype, made from heat treated ATI425 Titanium. HT was done by @Mecha. Handle is stab. Redwood burl and some Titanium and Bronze. OAL is 11.7" Blade is 7" long and .110" thick Weight is 3.24 oz

www.bladeforums.com

 

[Rockwelledge75]

I don't recall the alloy, as it was probably a one-off. The number of various ti alloys that are or were mass-produced and have an ASTM grade is quite low, but there are many oddball ti alloys that were made in small batches over the years, mostly several decades ago. While steel metallurgy has continued to advance, titanium metallurgical advancements have been stalling, and sort of repeating themselves for quite some time now.

The hardest ones I tested that weren't roached-out were upper 50s, and beyond that I was getting negative results as a blade. Generally speaking, with titanium alloys it's the crystalline phase and microstructure that matters, a lot more than hardness. "Alpha Prime" Titanium martensite doesn't want to yield, and it takes a lot to break it. It's flexible and tough, but isn't malleable and doesn't want to gall (edge doesn't get easily smooshed with use, which has always been the problem with ti) which helps immensely with edge-holding.

The hardness and other characteristics after creating "Alpha Prime" titanium martensite is going to be largely determined by the alloying elements, and trying to get it to read higher on a Rockwell hardness test isn't necessarily going to increase blade performance (though of course some things do follow along with hardness). The basic main point is that in this phase, it doesn't take a set or yield, therefore the fine-grained edge is going to go through whatever's being cut without issues, provided it's not highly abrasive. That's the mechanism by which a hardened ti alloy blade works.

The general consensus is that as a knife it functions a lot like a nice basic high carbon steel.

If you guys want to see a nice chef knife, made out of actual titanium alloy, here is a recent one made by BladeMan . I only heat treated it, he did everything else:

Titanium Kitchen Knife Prototype

Just finished this Kitchen Knife Prototype, made from heat treated ATI425 Titanium. HT was done by @Mecha. Handle is stab. Redwood burl and some Titanium and Bronze. OAL is 11.7" Blade is 7" long and .110" thick Weight is 3.24 oz

www.bladeforums.com

Very interesting properties with that titanium blade man used in his knife, a quick search revealed that it has a tensile strength in the longitudinal direction of 227,000 psi and in the transverse direction 310,000 psi.
It's interesting because there's such a difference in longitudinal compared to transverse strength, not sure if PM steels might be different, it's possible considering there transverse toughness is so much higher.
I also saw where this is an "alpha beta" alloy as oppose to an "alpha prime" or martensite titanium alloy, which from my understanding alpha beta alloys are weaker than the martensite forming and full beta alloys correct?

 

[Rockwelledge75]

I don't recall the alloy, as it was probably a one-off. The number of various ti alloys that are or were mass-produced and have an ASTM grade is quite low, but there are many oddball ti alloys that were made in small batches over the years, mostly several decades ago. While steel metallurgy has continued to advance, titanium metallurgical advancements have been stalling, and sort of repeating themselves for quite some time now.

The hardest ones I tested that weren't roached-out were upper 50s, and beyond that I was getting negative results as a blade. Generally speaking, with titanium alloys it's the crystalline phase and microstructure that matters, a lot more than hardness. "Alpha Prime" Titanium martensite doesn't want to yield, and it takes a lot to break it. It's flexible and tough, but isn't malleable and doesn't want to gall (edge doesn't get easily smooshed with use, which has always been the problem with ti) which helps immensely with edge-holding.

The hardness and other characteristics after creating "Alpha Prime" titanium martensite is going to be largely determined by the alloying elements, and trying to get it to read higher on a Rockwell hardness test isn't necessarily going to increase blade performance (though of course some things do follow along with hardness). The basic main point is that in this phase, it doesn't take a set or yield, therefore the fine-grained edge is going to go through whatever's being cut without issues, provided it's not highly abrasive. That's the mechanism by which a hardened ti alloy blade works.

The general consensus is that as a knife it functions a lot like a nice basic high carbon steel.

If you guys want to see a nice chef knife, made out of actual titanium alloy, here is a recent one made by BladeMan . I only heat treated it, he did everything else:

Titanium Kitchen Knife Prototype

Just finished this Kitchen Knife Prototype, made from heat treated ATI425 Titanium. HT was done by @Mecha. Handle is stab. Redwood burl and some Titanium and Bronze. OAL is 11.7" Blade is 7" long and .110" thick Weight is 3.24 oz

www.bladeforums.com

"The hardness and other characteristics after creating "Alpha Prime" titanium martensite is going to be largely determined by the alloying elements, and trying to get it to read higher on a Rockwell hardness test isn't necessarily going to increase blade performance (though of course some things do follow along with hardness). The basic main point is that in this phase, it doesn't take a set or yield, therefore the fine-grained edge is going to go through whatever's being cut without issues, provided it's not highly abrasive. That's the mechanism by which a hardened ti alloy blade works."

The only issue I can see here that might come up is if the blade is only say hrc 55 you might have some problems with edge rolling when cutting harder material like wood and bone even if the edge doesn't flatten out per say, unless you're saying titanium can spring it's edge back, which hey if that's the case that's pretrty wild.

How thin are the edges on good titanium knives anyways, have near zero edges been made with out much issue? can you get them hair splitting razor sharp and they can hold that for awhile?

 

[Mecha]

"The hardness and other characteristics after creating "Alpha Prime" titanium martensite is going to be largely determined by the alloying elements, and trying to get it to read higher on a Rockwell hardness test isn't necessarily going to increase blade performance (though of course some things do follow along with hardness). The basic main point is that in this phase, it doesn't take a set or yield, therefore the fine-grained edge is going to go through whatever's being cut without issues, provided it's not highly abrasive. That's the mechanism by which a hardened ti alloy blade works."

The only issue I can see here that might come up is if the blade is only say hrc 55 you might have some problems with edge rolling when cutting harder material like wood and bone even if the edge doesn't flatten out per say, unless you're saying titanium can spring it's edge back, which hey if that's the case that's pretrty wild.

How thin are the edges on good titanium knives anyways, have near zero edges been made with out much issue? can you get them hair splitting razor sharp and they can hold that for awhile?

Titanium Martensite / Alpha Prime are states a titanium alloy can be in, not a type of alloy. There's more to it than that, I was just blithering on about it being more complicated than just "harder = better."

A fully beta-phase metastable titanium alloy isn't necessarily better or stronger than an alpha-beta or near-beta alloy, and they can in fact be better for a blade, by a lot. There are many factors to it, such as the affects and interplay of various alloying elements, the heat treatment, work the billet has undergone, etc. Each alloy is significantly different from the next, and in general titanium alloys are really sensitive and responsive to everything you do to them, for better or worse.

I can mostly only speak for my own titanium blade work, but ya it springs back. No real problems with edge rolling or with zero edges, and the thinner the better.

If you're cutting things that are harder than HRc 55, then a titanium knife is the wrong tool for the job. Time to reach for a really good steel blade or tool.

 

[Mecha]

Very interesting properties with that titanium blade man used in his knife, a quick search revealed that it has a tensile strength in the longitudinal direction of 227,000 psi and in the transverse direction 310,000 psi.

I reckon that means it's harder to break it by bending it over, than it is by pulling it apart, then now ain't it!

 

[Danke42]

I reckon that means it's harder to break it by bending it over, than it is by pulling it apart, then now ain't it!

Pulling it apart is how I test all my knives. Just like Forged in Fire!

 

[Mecha]

Pulling it apart is how I test all my knives. Just like Forged in Fire!

Especially kitchen knives!

 

[Rockwelledge75]

Titanium Martensite / Alpha Prime are states a titanium alloy can be in, not a type of alloy. There's more to it than that, I was just blithering on about it being more complicated than just "harder = better."

A fully beta-phase metastable titanium alloy isn't necessarily better or stronger than an alpha-beta or near-beta alloy, and they can in fact be better for a blade, by a lot. There are many factors to it, such as the affects and interplay of various alloying elements, the heat treatment, work the billet has undergone, etc. Each alloy is significantly different from the next, and in general titanium alloys are really sensitive and responsive to everything you do to them, for better or worse.

I can mostly only speak for my own titanium blade work, but ya it springs back. No real problems with edge rolling or with zero edges, and the thinner the better.

If you're cutting things that are harder than HRc 55, then a titanium knife is the wrong tool for the job. Time to reach for a really good steel blade or tool.

Yea I understand that about the martensite, it's similar to how steel has a martensite crystal structure too and how certain elements namely carbon allow it to form more easily, I'm guessing with titanium there's elements in certain alloys that either help or retard the formation of that structure.

I thought maybe a fully beta alloy might be the best do to hardness but after a little more research from the link you posted me I see that's probably not the case since the more beta phase the alloy has the less martensite. It's hard to wrap your head around it first that softer phases of titanium produce the most martensite and that martensite is actually the springiest or highest yield strength ductile phase in titanium because in steel martensite is just hard and generally you don't want crystal structures like softer phase austenite messing with your martensite in steel but with titanium it's the opposite atleast that's what I'm gathering from my limited reading of just a few articles tonight, I'm by no means an expert so you tell me if I'm in ball park here or way out of field

lol I didn't mean cutting things harder than 55hrc, I meant that if your titanium is less hard than 55hrc it might cause problems cutting things like hardwoods but clearly this isn't the case as you've already said with these super springing high yield strength edges.

 

[Rockwelledge75]

I reckon that means it's harder to break it by bending it over, than it is by pulling it apart, then now ain't it!

I believe so yes, I've always understood yield strength as a material's ability to resist bending and taking a permanent set and tensile strength as a material's ability to resist being pulled apart. tensile strength doesn't really matter at all in knives although it tends to be quite high with higher hardness steels anyways.

 

[Mecha]

Yea I understand that about the martensite, it's similar to how steel has a martensite crystal structure too and how certain elements namely carbon allow it to form more easily, I'm guessing with titanium there's elements in certain alloys that either help or retard the formation of that structure.

I thought maybe a fully beta alloy might be the best do to hardness but after a little more research from the link you posted me I see that's probably not the case since the more beta phase the alloy has the less martensite. It's hard to wrap your head around it first that softer phases of titanium produce the most martensite and that martensite is actually the springiest or highest yield strength ductile phase in titanium because in steel martensite is just hard and generally you don't want crystal structures like softer phase austenite messing with your martensite in steel but with titanium it's the opposite atleast that's what I'm gathering from my limited reading of just a few articles tonight, I'm by no means an expert so you tell me if I'm in ball park here or way out of field

lol I didn't mean cutting things harder than 55hrc, I meant that if your titanium is less hard than 55hrc it might cause problems cutting things like hardwoods but clearly this isn't the case as you've already said with these super springing high yield strength edges.

Sounds like you got it. I call those very high beta alloys "over-alloyed" and they are not optimal for a blade. It's all a fine balance.

Though I have basic metallurgy instruction through welding school, I'm not a metallurgist. Just someone who has pursued, specifically, the making of high-performance titanium alloy swords, and I keep researching titanium metallurgy in order to continue advancing my craft and to understand my observations and repeatable results.

It just happens that these results make a worthwhile knife, not just a sword, which is significantly different.

It's all about testing. Sometimes I'll read an 80-page peer-reviewed article about some nuance of titanium alloys, just to find one single nugget of information that finally explains a persistent observation.

 

[Rockwelledge75]

Sounds like you got it. I call those very high beta alloys "over-alloyed" and they are not optimal for a blade. It's all a fine balance.

Though I have basic metallurgy instruction through welding school, I'm not a metallurgist. Just someone who has pursued, specifically, the making of high-performance titanium alloy swords, and I keep researching titanium metallurgy in order to continue advancing my craft and to understand my observations and repeatable results.

It just happens that these results make a worthwhile knife, not just a sword, which is significantly different.

It's all about testing. Sometimes I'll read an 80-page peer-reviewed article about some nuance of titanium alloys, just to find one single nugget of information that finally explains a persistent observation.

Oh wow that's really cool, I didn't even know you could make swords out of titanium, what's your favorite/ best alloy to use for that purpose? Do you find it can cut tougher things like tatami mats, coconuts, bamboo and the like?

Have any pictures you could send me in a PM? (don't want to clutter this thread up since it's about kitchen knives)

 

[Mecha]

Oh wow that's really cool, I didn't even know you could make swords out of titanium, what's your favorite/ best alloy to use for that purpose? Do you find it can cut tougher things like tatami mats, coconuts, bamboo and the like?

Have any pictures you could send me in a PM? (don't want to clutter this thread up since it's about kitchen knives)

Coconuts and tatami? Like butter. So easy. My favorite test medium is hard green bamboo.

Check out this thread:

Big fat titanium tanto

Described as a "sumo tanto" by the sword mounter who made the tsuka and saya, this is one of the very first welded-edge multi-alloy forged titanium blade billets I made, so it was a bit of a test piece. The body of the sword is 6al4vELI body implant alloy, welded to a BT23 Russian armor alloy...

www.bladeforums.com

And my subforum and website for more info:

Mad Science Forge

All things forged titanium! Visit the site at: Madscienceforge.com

www.bladeforums.com

www.madscienceforge.com

There was a spinoff of Forged in Fire called, "Knife or Death," sort of a blade obstacle course. I was lucky enough to be able to take part, season 2, episode 12, called "Seax and Violence." Using a ti alloy blade, and showed that it can hang with the steel blades, at least.

My favorite alloy is a Soviet-era Russian ballistic armor plate alloy, called BT23 or VT23. Perhaps not the best for a knife, but really good for a long thin blade.

 

[BladeMan]

How thin are the edges on good titanium knives anyways, have near zero edges been made with out much issue? can you get them hair splitting razor sharp and they can hold that for awhile?

I have done that, yes. No issues at all. In fact most of the smaller knives i do have an edge prior to sharpening that is around 0.1 mm / 0.0039" thick.

Oh wow that's really cool, I didn't even know you could make swords out of titanium, what's your favorite/ best alloy to use for that purpose? Do you find it can cut tougher things like tatami mats, coconuts, bamboo and the like?

I do have a few of Mechas blades, and since they get razor sharp and are also thin there is no reason why they should not could mats and the like.

 

[Rockwelledge75]

Coconuts and tatami? Like butter. So easy. My favorite test medium is hard green bamboo.

Check out this thread:

Big fat titanium tanto

Described as a "sumo tanto" by the sword mounter who made the tsuka and saya, this is one of the very first welded-edge multi-alloy forged titanium blade billets I made, so it was a bit of a test piece. The body of the sword is 6al4vELI body implant alloy, welded to a BT23 Russian armor alloy...

www.bladeforums.com

And my subforum and website for more info:

Mad Science Forge

All things forged titanium! Visit the site at: Madscienceforge.com

www.bladeforums.com

www.madscienceforge.com

There was a spinoff of Forged in Fire called, "Knife or Death," sort of a blade obstacle course. I was lucky enough to be able to take part, season 2, episode 12, called "Seax and Violence." Using a ti alloy blade, and showed that it can hang with the steel blades, at least.

My favorite alloy is a Soviet-era Russian ballistic armor plate alloy, called BT23 or VT23. Perhaps not the best for a knife, but really good for a long thin blade.

Seems BT23 can only be heat treated to rockwell 48, is that really sufficient for your swords?. They look absolutely amazing though, Truly spectacular craftsmanship. I can only imagine very light too.

 

[Mecha]

Seems BT23 can only be heat treated to rockwell 48, is that really sufficient for your swords?. They look absolutely amazing though, Truly spectacular craftsmanship. I can only imagine very light too.

I'm done here. Thank you for the compliment. I already explained how the hyper-focusing on Hardness, Rockwell C scale numbers is not instructive in this case.

 

[Rockwelledge75]

I'm done here. Thank you for the compliment. I already explained how the hyper-focusing on Hardness, Rockwell C scale numbers is not instructive in this case.

Sorry I was just trying to bring it back to the topic of knives, I'm sure your swords perform admirably even at somewhat lower harnesses because of that amazing spring like yield strength of titanium. But if we're talking knives personally in my option I think the blade material needs to be a higher hardness especially if it doesn't have wear resistant carbides in it, has nothing to do with resistance to edge deformation I know we already went over that.