What is DLC, what does it do and how long will it protect a blade?

[Sharpdressed man]

I just got my sixth "arachnid", a Paramilitary 2 all black. So far it seams perfect in every aspect. I cant seem to put it down.

The blade has "DLC" on it. It is not at all like a paint or cerocoat like other brands ihave. This stuff feels rough hard and and has a non shiny flat finish.

I read about it on Goggle but I would like to hear the real story from the Pros. What is this stuff and what are the advantages and disadvantages of having this coating?

[Bill1170]

Diamond-Like Carbon is very hard, so it protects from scratches. It's main function is light discipline, meaning it is non-reflective so your blade glint doesn't give away your position, useful in combat. I don't know if it has any protective properties with regard to corrosion, but s30v is pretty good in that regard, anyhow.

[Zenith]

http://bit.ly/1cFECcp

:D

[Syncharmony]

One thing to keep in mind is that is pretty cool, is that the DLC coating on the blade is actually tougher than the steel underneath it. At least that is what I've read and the abuse videos I've seen collaborate that little factoid. One video I saw had someone taking a DLC coated Paramilitary 2 through it's paces and guy was basically stabbing and tearing through aluminum cans with the knife. After he was done, the coating on the blade looked about 10 kinds of messed up with scratches running all along it. It looked like the coating was ruined, even the reviewer thought so since it was his first experience with the coating.

He cleaned it up though and it looked like new and it was amazing. Since the coating is so hard, what look like scratches are actually just leftover residue from what you've been cutting. It's some pretty cool stuff and is probably the best coating material on the market I would imagine.

[Evil D]

It's job is to make the blade non reflective. Period. It isn't a rust prohibiter. It will resist scratches better than most steels will but will also completely chip off if hit hard enough. The coating itself is stronger than the bond that adheres it to the blade.

[Michael Janich]

DLC (Diamond-Like Carbon) is molecularly bonded to the surface of the material and will not "chip off if hit hard enough." It also does in fact increase corrosion resistance.

For a more technical explanation of the process used to apply it and the benefits of the coating itself, I went to IonBond, the folks who developed it. This is from their web site:

PACVD Technology

PACVD (Plasma Assisted Chemical Vapor Deposition) is a vacuum based process used to deposit DLC (Diamond Like Carbon) coatings, also known as ADLC (Amorphous Diamond-Like Carbon). All educts of the PACVD process are gaseous. This makes it suitable for coating 3D components uniformly, without the need for rotation as is necessary in PVD.

The coatings are amorphous in structure and contain around 70% sp3 bondings, which accounts for the high hardness of the coating (10-40 GPa).

The PACVD process is used for coating a very broad range of conductive and non-conductive substrate materials at temperatures below 200° C. The typical thickness is in the range of 2 – 3 µm.

DLC coatings feature excellent hardness, wear and low friction properties under dry or deficient lubrication conditions. They are ideally suited for tribological systems found in engines, machines and other mechanical assemblies with sliding and rolling movements. The perfect surface finish without any post-treatment makes them ideal for high precision injection molding tools as well as for decorative purposes. DLC is chemically inert and biocompatible which allows for its application on medical components and implants.

Broad range of substrate materials
No distortion of high precision substrates
No post treatment necessary
Gaseous process for uniform coating of 3D geometries without rotation
Green technology with respect to educts, process and products

Here's a link to additional information that substantiates its qualities of hardness, adherence, and corrosion resistance:

http://www.renishaw.com/advancedmateria ... ngs--14211

In my previous job, many of the knives we produced were DLC coated--including DLC-coated A2 tool-steel blades. I saw many of these that had seen extensive hard use in tactical environments. The DLC held up extremely well. Even when the exposed steel at the edges of blades was allowed to corrode, the corrosion did not "bubble" under the DLC like conventional coating or plating processes and stopped where the DLC started.

I hope this helps.

Stay safe,

Mike

[Liquid Cobra]

Whoa. So....why aren't the clips coated in DLC? Problem solved!

[phillipsted]

I've scraped off some of the DLC on my Para2 right along the edge of the spine. This was caused by inserting it into a Kydex necker sheath. Not much came off - and it is right along the sharp edge of the spine. But with normal wear and tear, it can come off.

Strong, hard stuff it is - but invulnerable? Nope.

TedP

[JNewell]

I've gotten the impression that there are several different processes that are (probably incorrectly) referred to as "DLC" and that they differ somewhat - is that accurate?

[Blerv]

I've gotten the impression that there are several different processes that are (probably incorrectly) referred to as "DLC" and that they differ somewhat - is that accurate?

Like the folks that improperly treat tools and spray them with Mystery Coating X and believe they have sealed the wardrobe to Narnia? :)

[bdblue]

I've gotten the impression that there are several different processes that are (probably incorrectly) referred to as "DLC" and that they differ somewhat - is that accurate?

Yes, one person's "black" coating can be much different from another person's coating. Spyderco happens to have one of the best, Benchmade's coating isn't as good.

[chuck_roxas45]

Its another thing for knife nuts to discuss and obssess over every little detail of composition, process, and utility.

[bengaiser]

Whoa. So....why aren't the clips coated in DLC? Problem solved!

Maybe too expensive? What would be cool, is to be able to order a DLC clip as an accessory item (if indeed cost is the issue, this would not raise knife costs for casual users).

[Liquid Cobra]

Maybe too expensive? What would be cool, is to be able to order a DLC clip as an accessory item (if indeed cost is the issue, this would not raise knife costs for casual users).

Agreed.

[demoncase]

DLC coatings- like all surface treatments from the more traditional carburising and nitriding to the more modern PVD and plasma coatings- vary quite a bit in practice as described, even when a 'propriety' 'recipe' is being used.

The reasons for this are myriad in detail, but broadly come down to surface preparation- get the surface finish wrong on a material that self-passivates like just about any steel and your wonderful super-tough DLC coating will peel off like the skin on a custard.
Batch-to-batch variations in the substrate material (such as small variations in micro-constiuents like Vanadium) which wouldn't make any difference in normal practice can show up drastically when applying a coating over the top in terms final colour, sheen of the finish and indeed adhesion.

And no coating is indestructable, as has been pointed out- they are wear resistant, not wear proof.