What are the Pros and Cons of Titanium as a Knife Blade?

000Robert

000Robert

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I have been looking for a thread to answer that question and am coming up short. Could someone give a good answer? I even worded it different ways in the search function. I have never owned or even remember seeing a Titanium blade in person. Thanks.
 
It really depends on the use. For a sword that will likely be a wall hanger, it is superb. For a seldom used knife that needs not to rust, it is good. For a chefs knife that will cut all day long, it will suck.

The alloy also determines some of the possible issues ad uses. Mecha is the king of Ti. He can do HT procedures on certain Ti alloys that will harden it up to what a cheap pocket knife used to be.

For a seldom used knife, like a boat knife or survival knife, Ti is a good choice. It won't rust or corrode and will be sharp enough for the required occasional use. I have made Ti divers knives for the same reason.

There are also some very different considerations in working Ti over steel. One big difference is the sparks can set things on fire much easier. It is tough to grind. There is a toxicity issue, too.
 
Stacy E. Apelt - Bladesmith said:
It really depends on the use. For a sword that will likely be a wall hanger, it is superb. For a seldom used knife that needs not to rust, it is good. For a chefs knife that will cut all day long, it will suck.

The alloy also determines some of the possible issues ad uses. Mecha is the king of Ti. He can do HT procedures on certain Ti alloys that will harden it up to what a cheap pocket knife used to be.

For a seldom used knife, like a boat knife or survival knife, Ti is a good choice. It won't rust or corrode and will be sharp enough for the required occasional use. I have made Ti divers knives for the same reason.

There are also some very different considerations in working Ti over steel. One big difference is the sparks can set things on fire much easier. It is tough to grind. There is a toxicity issue, too.
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Grade 5 is 6Al4V
It's used in medical implants and jewellery right ?
 
Yes, we use titanium in jewelry. Since the grade doesn't matter much, we use whatever is cheap and available. 6Al-4V is the most common in the thin sheets it we want. We cut and shape it then use a torch or oven to color it. Ti rings are made in a factory from thick wall tubing. We also use niobium for wire-work earrings.

I have a bunch of titanium hips and knees that were in the recycle bin at a local crematorium. They were going to dump them in the trash because shipping was as much as they would get for the metal. Don't know what I will do with them, but the hips seem easy to convert to handles on machines :eek::D . Imagine changing the three arms on the drill press wheel to hip joints, or using one for the tension arm on a grinder.
 
WValtakis said:
On the contrary, some alloys of Ti hold an edge remarkably well...similar to a low alloy steel. I'll tag in Mecha Mecha though, he nerds on it way harder than I do;)
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Thanks. I thought about sending him a PM but I decided not to bother him.
 
I have a Ban Tang titanium blade with a carbidized edge.
In cutting fibrous material (rope) it performs well enough since the edge is effectively serrated.
I dare not put it to hard use, but it works well enough in the box opening domain.
It's about 6" OAL, 1/16" thick. Although only speculation, I am concerned about it taking a set (permanently bending) if worked hard.
 
Since i only make Titanium knives that are heat treated by Mecha Mecha , i can tell you that it will hold an edge and can be ground very thin. It is like a simple carbon steel in terms of edge holding and as easy to sharpen too with the advantage of beeing lighter, no rust ever and springy temper.
 
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Edge holding is pretty important to me. I might try a Titanium blade some time in the future. Being easy to sharpen doesn't matter to me since I use diamond stones.
 
I have had good luck with Titanium blades. The Mission knives (first photo) are made from hardened beta Titanium and seem to hold an edge respectably. One neat thing about Ti blades is that the edge rolls instead of chipping when you hit something hard. The roll can easily be straightened by pulling the knife (edge trailing) along a steel pipe.
Boker made some knives out of this material (top knife second photo) one of which I Carbidized with Titanium Carbide which is much harder than the Tungsten Carbide that is usually used in Carbidization. The knife was chisel sharpened (single bevel) , and the TiC was applied to the flat bevel.
The bottom knife in photo 2 uses a proprietary material that has TiC mixed into it for wear resistance as well as some Silver to enhance ductility. This blade is best sharpened on Diamond or Cubic Boron Nitride abrasives to prevent Carbide tear out.
The bottom photo has knives that I ground into clip points. The 4th knife has a CeraTitan blade like the chef knife above.
image.jpegimage.jpegimage.jpeg
 
There's a lot to say, but BladeMan summed it up. Most users of mine say it's like using nicely-tempered 1084 or 1095 in use as a knife, at least the ones made in certain alloys and heat treated a certain way.

Most ti alloy is 6al4v which does not get very hard and in fact is made to bend or gall rather than crack, and remain flexible and not take a gross set under stress. The alloys and heat treatment I use are different, and don't compare to titanium alloys as normally seen and heat treated for typical fabrication uses. Or other titanium alloy blades (I actually like tungsten carbide 6al4v blades a lot for getting work done).

After heat treatment, the blade will normally not take a set, gall, or smoosh anymore, but will instead break off a piece of the edge if subjected to too much shock/impact stress, which takes a LOT to do since the alloy is still so resilient even in this hardened state, which is called "alpha prime" or also, titanium martensite. This extreme resilience against taking a set, a permanent bend, galling, or otherwise yielding to the medium getting cut is the mechanism by which the blades stay sharp, rather than through hardness or carbides. They can be VERY thin and yet still strong and resilient.

Rockwell hardness is not very useful in determining the mechanical characteristics of titanium alloys. One of my titanium knives (low 50s HRc) was tested next to a Japanese high carbon steel knife at low 60s HRc, and found to be similar in cutting performance and edge-holding. Another one was used by the owner at a packaging factory to cut thick cardboard and other materials all day and it was still sharp when he went home that day. One guy as been using a machete for around 7 years and has not sharpened it yet. I can't even imagine a kitchen knife ever getting dull at all, though eventually I guess it would.

Almost all of the information I can give on the comparative performance is anecdotal, and I can only speak for my own and BladeMan's blades which I heat treated. I can say with confidence though, that almost everyone who's used them has been pleased or even amazed. It works fine, even very well as a knife, and in my opinion is amongst the very best materials imaginable for a sword or long blade which have different considerations to address.
 
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All that said above, the pros and cons when used as a knife:

Pros:
-no rust
-tough and resilient
-can be very thin
-easy to maintain, very low maintenance
-lightweight
-resistant to crack propagation
-will not break while batoning or subjected to shock stress


Cons:
-unlikely to compare to the high blade performance of advanced wear-resistant hard steels
-lower hardness and density means can't chop a cinderblock without damage to the thinnest part of the edge
-low density/weight means heavy chopping/cutting requires speed (can be dangerous)
-more likely(?) to get dull when cutting highly abrasive materials like sandbags


Simply put, titanium, in the right alloy and with the right heat treatment, does function well as a knife and is totally worthwhile to use, and can even become the favorite knife of many users. It's extraordinary as a long blade for several reasons.

Just like amongst the various steels, which are all different, titanium alloy is yet another way to get the job done, with its own quirks, nuances and feel. It by no means displaces steel, but I say it's well worthy of taking a seat with them at the round table of cutlery.
 
000Robert said:
Thanks. I thought about sending him a PM but I decided not to bother him.
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I like getting bothered. :D Many times it becomes a phone call because I'll only poke at a smartphone for so long.

My website, which seriously needs an update, has some FAQs and a bit more info.

Mad Science Forge - Forged Titanium Swords and Knives - FAQ

Forged Beta Titanium Swords and Knives | Welcome to Mad Science Forge, the secret headquarters, laboratory, and manufactorium of the original forged titanium alloy swords. Beta Titanium Sword and Knife
www.madscienceforge.com www.madscienceforge.com
 
The performance of Titanium blades is very similar to Stellite blades in my experience. Great edge holding at lower Rockwell hardnesses. Great corrosion resistance.
 
Mecha said:
I like getting bothered. :D Many times it becomes a phone call because I'll only poke at a smartphone for so long.

My website, which seriously needs an update, has some FAQs and a bit more info.

Mad Science Forge - Forged Titanium Swords and Knives - FAQ

Forged Beta Titanium Swords and Knives | Welcome to Mad Science Forge, the secret headquarters, laboratory, and manufactorium of the original forged titanium alloy swords. Beta Titanium Sword and Knife
www.madscienceforge.com www.madscienceforge.com
Click to expand...

Texting gets old for me quick as well. But I use a PC mostly online and use my phone for a phone. Titanium being a toxic metal, it is ok to use for cutting food?
 
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