Need some Ti advice (finish, grade, location)

[Rilner]

Morning chaps!

I plan to use Titanium more extensively from here on out, but still unsure about a few of its properties...

Finish: As I understand it, Ti naturally reacts with air (or at least Oxygen in the air) to develop its own sort of oxidized barrier which protects the bulk of the metal from corrosion and so on and naturally thickens over time. How would the finish affect the metal aside from aesthetics? Other threads I've perused have touched on how nice looking stonewashed finishing vs. other types is, but not so much in terms of what other qualities would be affected. I like the look of stonewashing, but not at the cost of performance; corrosion resistance is of particular importance because of a humid climate and regular-ish exposure to water. Would stonewashing increase rust resistance, lower it, or neither?

Grade: As for grade, I keep hearing a lot of hype for Grade 5, but am not sure exactly how much stronger it's supposed to be when compared to Grade 4, and otherwise how it's supposed to be much more desirable outside of that, unless workability is easier. I wouldn't know ~ just buy them, don't make them (not yet anyway). Some of the higher numbered grades on paper look impressive, but it seems the higher you go after a certain point, the less readily available it seems to be (commercially, at least).

Also trying to figure out which grade would be best for A) strength + anti-rust + edge holding and B) impact toughness + anti-rust (i.e: knife vs. hammer/hatchet)


Location: Finally, where should I buy from? I *know* the USA is excellent, but for smaller accessories (idk, belt buckles n' such) is China an entirely bad idea? I keep reading "yes" but surely someone, somewhere, in some company out of all those people are reputable. It's just that the cost in some scenarios is so much lower.

P.S: You'd think we Canucks would have the element and services surrounding it in abundance as well, since we seem to extract more of it than most of everyone else... >.>

 

[gdwtvb]

I have a hobby of making things out of titanium, and it is my favorite knife handle material. First as far as edge holding ability, titanium stinks compared to just about any modern steel.

These are the generally accepted benefits of titanium:

It is virtually non-corrosive, so it is used in highly corrosive environments, like salt water. (Diving knives)
It is reasonably flexible without forming stress fractures from repeated flexing like most Aluminum alloys. (Which is why it works well in jet fighters, or as a locking side of a Reeve integral lock folding knife.)
It is non-allergenic, making it suitable for implantation in the human body. (Hips, knees, the screws in my back, etc.)
Pound for pound it is stronger than steel. (This is a mass measurement, not size.)
I don't believe that the titanium oxide coating builds up over time, it just forms immediately with the contact with air. It can be forced to build up thicker through electro anodizing causing it to refract light and make pretty colored titanium. The difference is that the coating that immediately forms on titanium is a thin coat that is bonded directly to the titanium which blocks any other oxidation from occurring (Think a couple atoms thick.) unlike iron oxide that is red, crusty, and gets worse.

The cons being:
Hard to machine...I wish I had a nickel for every ruined drill bit.
The same elasticity makes sharpening titanium difficult, it wants to bend at the edge rather than be ground to a sharp point...this is why it is also such a pain in the butt to machine. To visualize, try to imagine trying to grind a piece of solid rubber to a sharp point.
Titanium on titanium movement tends to gall. (Titanium is not well suited to sliding against other titanium, which is why it is a rather poor choice for making things like titanium flashlights, the threads aren't smooth. )
Titanium is a rather poor conductor of heat or electricity. (This does make it seem 'less cold' in the winter, or less scorching hot when left in the sun than other metals though.)

As far as finishes go, they would not affect anything other than appearance. Polished titanium scratches rather easily, and stonewashed or bead blasted titanium hides the scratches better.

I use grade five, but for no real reason other than it's available in the sizes I like to work with. I make necklace charms mostly. For my use, I like the hypoallergenic properties, the lack of corrosion, and the fact that I can anodize my creations all kinds of pretty colors with baking soda and a couple batteries. Frankly, titanium is a pain in the butt to work with, and I spend more money replacing worn out out drill bits, saw blades, and Dremel carbide cutters than I spend on titanium.

Hope this helps,

Grizz

 

[Mecha]

Pretty much what gdwtvb said, except that "titanium" in its common alloys may not hold a good edge, but heat-treatable beta ti alloys can be very good in this regard. People also have great results with knife edges that are carbidized 6al4v.

Grade 5 (6al4v) is simply the most common ti alloy around, constituting something like 90% of all alloyed titanium that's made. It's a really nice all-around alloy for structural purposes, but it's made for toughness and flexibility - formulated so that it resists hardening. It's what's commonly referred to simply as "titanium"

Grade 4 is pretty much just unalloyed titanium, of which there are several grades based on purity and oxygen content. There are also several different grades of 6al4v. Titanium alloys have drastically different properties than the metal in its pure form (just like iron), and many beta alloys are made in small batches for specific purposes and have no grade number at all.

http://www.engineershandbook.com/Tables/titaniumgrades.htm

Titanium alloys are impervious to rust. Over time, and I mean decades, the ti will start to look more gray, that's it.

These alloys are very difficult and costly to make. American, Russian, Japanese or Brazilian titanium is trustworthy. It's worth it to get the good stuff for a blade, because purity is of utmost importance in ti alloys.

Grade 5 titanium is WAY better than pure ti in pretty much every way for anything that aren't just trinkets. It's classified as an "alpha-beta" ti alloy; it's a cross between an alpha- and a beta-ti, and harbors both crystalline phases at room temperature, in various forms. Any alpha-beta alloy should make a great blade if carbidized, and these alloys also work-harden (toughen). Fully beta-metastable titanium alloys can have wild and greatly varying properties, and are quite responsive to heat-treatment.

tl; dr version:

Any finish you want, Grade 5 with tungsten carbide, and USA.

 

[Rilner]

That's awesome! Thank you both for your replies!!

Do you know anyone who could make me some Ti roller buckles and belt tips? Need them to accommodate 40mm straps. Tip engraving would be ideal (I have shapes I want ready) but not essential. Really, REALLY want some in stonewashed grade 5 (I'm convinced)

 

[Rilner]

Also, I toyed with the idea of asking Strider if they would make a Ti version of their BS Hatchet. No idea if they entertain customs or not... have a friend in Alabama who makes hawks but he refuses to play with it for the reasons you mentioned...

 

[Mecha]

Might have to make the tips and buckles yourself: grade 5 (6al4v) sheet and round rod stock, heat it up with a propane torch and commence "micro-forging." Once it's glowing orange, it will be easy to bend permanently into shape. GMAW/tig torch for welding.




Wait... what? You want a Stridor what? A REAL titanium alloy hatchet is a rare thing, but they're sometimes made and I believe I've seen them in the custom knife maker's sale section of this forum.

 

[Rilner]

https://imgflip.com/memegenerator

 

[Mecha]

Exactly. You heat up the spaceship metal with fire, then forge it with hammer and willpower!

 

[Rilner]

https://imgflip.com/memegenerator

 

[Rilner]

Actually just finishing a deal with some dudes in China. They make all the belt parts (except belt tip at first, made a deal with them to temporarily subsidize cost of getting the tip mold) in Titanium, will use grade 5 if I want (asked for grade 4, it's a belt) and can do laser engraving and use smooth or stonewashed finish (STONE! O_O). I asked for a roller buckle, they said they could do it.

Somewhat expensive, but it's Ti. Presuming my liking of their first set, I'll be going back for more. Just could not find anyone in North America to do that kind of stuff. Actually not too many people over there either! Excited for it ^_^

 

[Mecha]

Grats, Rilner! I'd pimp a titanium-buckled belt, just like Danger Mouse.

 

[Rilner]

*Only the Aww ya remains...*


https://imgflip.com/memegenerator

 

[mete]

Did someone call me ?? DM

Mecha ,what alloy does the Sebenza have ? it's easy to engrave . I've engraved mine

 

[Danke42]

You should delete your link to the auction site.

Re Titanium oxidizing. Yes it does get thicker with time but since we're talking nanometers you can just call it stable for this application.

 

[Rilner]

Might have to make the tips and buckles yourself: grade 5 (6al4v) sheet and round rod stock, heat it up with a propane torch and commence "micro-forging." Once it's glowing orange, it will be easy to bend permanently into shape. GMAW/tig torch for welding.



Wait... what? You want a Stridor what? A REAL titanium alloy hatchet is a rare thing, but they're sometimes made and I believe I've seen them in the custom knife maker's sale section of this forum.

Do you think cryo treatment would alter Ti to such a point where edge retention/wear resistance would be practical for that (hatchet) application without taking away too much toughness?

 

[Rival1314]

This thread is probably best suited for the knifemaker secion of this forum...you will find a lot of answers there.

Do you think cryo treatment would alter Ti to such a point where edge retention/wear resistance would be practical for that (hatchet) application without taking away too much toughness?

Cryo treatment would have no impact on edge toughness or retention on standard ti. To create a working cutting edge out of ti you need to carbidize it. I have been making knives out of titanium for a little over a year, others have been doing it longer. Adding a layer of tungsten carbide to the edge gives it a HRC of 71 on the carbide side, combined with the softer titanium makes for a nice cutting edge that is easy to maintain and completely corrosion resistant. Not sure how it wouold,stack up on a hatchet as you would be using a lot more force than a regular knifeblade...but im certain it would work out ok.

Whats a thread without pics right...you can see the carbide added to the blade in the pics:

Regarding the OP questions about quality...stick with grade 5. The grade 4 and Chinese ti is a variant called tc4 titanium, it has small amounts of toxins and impurities within the alloy, which is why you need grade 5 or higher for use in medical/aerospace applications. The price difference is minimal, so don't be cheap;-)

 

[Danke42]

Cyro makes Ti more malleable.

The idea is to have it done prior to assembly. That way you can work the mater harder.

Post production it doesn't made sense.

Be sure to check your bank account. A good custom hawk will run you $5-800. Ti should just about quadruple that.

 

[Rilner]

-THANK YOU- for this information ^^^^ Gold.

 

[Rilner]

Cyro makes Ti more malleable.

The idea is to have it done prior to assembly. That way you can work the mater harder.

Post production it doesn't made sense.

Be sure to check your bank account. A good custom hawk will run you $5-800. Ti should just about quadruple that.

Thank you too ~ ^^^^^ Silver AND Gold.

 

[Rilner]

This thread is probably best suited for the knifemaker secion of this forum...you will find a lot of answers there.



Cryo treatment would have no impact on edge toughness or retention on standard ti. To create a working cutting edge out of ti you need to carbidize it. I have been making knives out of titanium for a little over a year, others have been doing it longer. Adding a layer of tungsten carbide to the edge gives it a HRC of 71 on the carbide side, combined with the softer titanium makes for a nice cutting edge that is easy to maintain and completely corrosion resistant. Not sure how it wouold,stack up on a hatchet as you would be using a lot more force than a regular knifeblade...but im certain it would work out ok.

Whats a thread without pics right...you can see the carbide added to the blade in the pics:

Regarding the OP questions about quality...stick with grade 5. The grade 4 and Chinese ti is a variant called tc4 titanium, it has small amounts of toxins and impurities within the alloy, which is why you need grade 5 or higher for use in medical/aerospace applications. The price difference is minimal, so don't be cheap;-)

Glad to know that difference for grades. How would that process you outlined work out for a straight razor? I was hoping to eventually get a hold of one in Ti, because of corrosion resistance (I'm a little picky about things that scrape my face like *CRRSSHHHT*) and toughness (ever tried to shave with a bent or rolled or chipped razor?) I know it's up to the user to maintain their equipment but... *shudders* I'm not sure how it would be price wise compared to say an entire full tang hawk.

http://www.discommon.com/goods/the-straight-razor-titanium <---- this is what I've found so far within that realm. Would you think that to be a typical price for that in Ti? Could you make a razor in Ti? From what you've explained of the carbide effect, it would substantially reduce the effort needed in terms of sharpening and stropping. I think I'm developing a Ti obsession. LET Ti RAIN FROM THE SKY (away from my head)

P.S: Will check out that section.