All About Pocket Knives

Does rainbow or titanium coating do anything to a knife except color it?

How is this done?

I'm not knowledgable enough to answer, but since it's been two days and no responses I'll chime in, just to spur responses if nothing else.

My impression was that rainbow coating as well as other oxide coatings were done via anodization. I think I assumed titanium coating was done the same way, but thinking about it now, I'm not so sure.

I'd like to know too, if anyone has the answer.

Thanks Longbeachbum.
Anyone else have any info or "theories"?

Some info...

http://www.agrussell.com/knife_informat ... tings.html

http://www.efunda.com/processes/surface ... atings.cfm

Bill

Titanium nitride (TiN) is an extremely hard (~85 Rockwell C Hardness or ~2500 Vickers Hardness)1, ceramic material, often used as a coating on titanium alloy, steel, carbide, and aluminum components to improve the substrate's surface properties.

TiN has excellent infrared (IR) reflectivity properties, reflecting in a spectrum similar to elemental gold (Au). Depending on the substrate material and surface finish, TiN will have a coefficient of friction ranging from 0.4 to 0.9 versus itself (non-lubricated). Typical formation is a face-centered cubic crystalline structure with a roughly 1:1 stoichiometry. TiN will oxidize at 600 °C (~1100 °F) at normal atmosphere, and has a melting point of 2930 °C.

Uses
Far and away the most common use for TiN coating is for edge retention and corrosion resistance on machine tooling, such as drill bits and milling cutters, often improving their lifetime by a factor of three or more.
Because of TiN's metallic gold color, it is used to coat costume jewelry and automotive trim for decorative purposes. TiN is also widely used as a top-layer coating, usually with nickel (Ni) or chromium (Cr) plated substrates, on consumer plumbing fixtures and door hardware. TiN is non-toxic, meets FDA guidelines and has seen use in medical devices and bio-implants, as well as aerospace and military applications.

I hope that covers it...........

Great info, Thanks!

I went ahead lifted some verbiage out of the AG Russell link Bill posted, specifically regarding TiN coating:

"The newest and toughest of all plating is the titanium nitride plating or coating which has been available to some extent for the past ten years or more. Many people thought that plating a sharp knife with this material would insure that it would stay sharp for a long time. The problem is that plating makes it less sharp. When sharpening you remove the coating from both sides of the edge, exposing the steel so that nothing is gained. Buck's new process is very like that of Robeson in the 1940s, in that the knife is sharpened only on one side and relies on the hardness and wear resistance of the titanium nitride to keep the knife sharp. This works, at least in the short term. Time may show that it will work in the long term as well. My tests have been positive enough that I will be recommending some of these Buck knives to my customers. For this to work YOU MUST NOT sharpen the other side of the edge. The titanium is of course fully rust resistant."

So I guess we can now say we know that titanium coating at least potentially affects blade performance, at least if the blade is chisel ground. I would imagine it would also make reprofiling all that much more difficult, due to it's high hardness and wear resistance.

Also, since TiN is a nitride coating, not an oxide coating, I deduce (after reading Bill's other link) that it is not done through anodization. Therefore it would appear that the question regarding how TiN coating is applied hasn't been answered, unless I missed that somewhere.

And lest anyone put any stock in these technical observations, be advised that I'm an insurance guy with a degree in English literature.

Gentlemen,

Here in this part of The South we do it by Sputter Deposition, otherwise known as Sputtering.

It is the process where the material is not thermally vaporized and the atoms are physically redirected from the source material to the substrate by collision from a bombarding particle. The distance from the source to the substrate is much shorter than that of vacuum deposition.
Sputter can also be done under a higher plasma pressure of 5-20 mTorr and the material is heated by collisions with gas molecules.
The sputtering source itself can be made of elements, alloys, mixtures, or compounds. Titanium Nitride (TiN) and Zirconium Nitride (ZrN) along with some Boron mixed Diamond-like carbon (DLC) are common coatings for this process.
This form of deposition is commonly used in semiconductor manufacturing, on architectural glass, reflective coatings, compact discs (CDs), magnetic films, dry film lubricants, and decorative knife coatings.

Them folks over at Oak Ridge may not be able to drive a car, but they can do some funky stuff with metals.

9ball

Thank you for that unique clarification of the process, Mr. Cuemaster.

I've got to say, that for us folks here in the Southwest, it all does sound a little bit like "pi**ing into a strong wind... ... but then, it might just be the heat today.

Adios,

El Lobo

You are welcome.

Just do not P in my pool.

Thanx Guys for the info!

Now let me make sure I got this straight...

All I gotta do is P in a pool when the wind is blowin, dip a knife in it, and it'll come out with a genuine titanium rainbow coating that'll stay sharp forever, and never rust, right?

That's one way of lookin' at it...

Bill

Hey Whittlenut ,
Yes, Bill is correct about lookin' at it and you are on the right track. The water temp would have to be around 2500-3000 Degrees F, a small 10,000 gallon pool would be your best bet and you would have to drink about a pound of Titanium dust/grindings with a gallon of water before juming in also. Be sure it is distilled water.
Then P (in your pool, of course) on your item.
Kinda like underwater sand/bead blasting, if you catch my drift.

It may help if you had some morphine or other major narcotic mixed in there. In case there was blockage, it may feel like passing a million kidney stones before you get the job done.

This is all in theory and you are doing this at your own risk. Let us know how everything comes out. Post some before and after photo's/images if possible.

Good Luck
9ball

BTW:If you did it with the vacuum method, you would not be able to breathe.

9ball said:

BTW:If you did it with the vacuum method, you would not be able to breathe.

I think it's safe to say that it is already hard to breathe from all the BS oops I mean scientific discussion going on...

That is what I like about this site. No matter what it is or about, you can find it right here on AAPK. It is like a Big Book of Knowledge.

9ball

Facts.......Just The Facts
Sgt. Joe Friday LAPD