Diamond-coated Steel

An anonymous reader writes "A Dutch chemist has successfully coated steel with a layer of diamond, opening the possibility for insanely strong tools that almost never wear out -- not to mention armor tough as, well, diamond-coated nails. From Science Blog."

Comments

Tools?

[PD]

How about engine parts? They might make an engine that would run for a half million miles with normal oil changes.

Re:Tools?

[Smidge204]

They do... typically deisel engines can last up to and over a million miles with typical (and scheduled) maintainance. Take care of your car's engine and you might get more than a lifetime's worth of use out of it, too.

I'm more interested in the bonding issue. If heat can effect the bonding (because steel and diamond have very different thermal expansion coefficients), then how useful would this really be for, say, cutting tools?

Also, I can't see armor plating as being all that impressive. diamond coated steel might have excellent wear characteristics, but since the layer is just atoms thick (I'm assuming, article didn't say... maye you could build it up with repeated coatings?) it wouldn't offer much to resist bending or puncture... thus not being a big improvement for armor. Diamond is also brittle, meaning it'll be easy to crack if you bend or chip it.

Heat transfer properties, however, are very interesting. If they can build up layers, you could start with a thin wire forms and make diamond heat sinks... and diamond is a very good heat conductor. (based on the process they describe to make it, doesn't sound too expensive either... heating up hydrogen and methane gas? Pfft!)
=Smidge=

Images

[Pall Agamemnides]

This page has highly-magnified images of what this process does to steel. Here are direct links to the images:

Not wanted: graphite on tool steel
Wanted : a good-adhering diamond layer on tool steel with an intermediate layer of chromium nitride

Re:armor?

[GigsVT]

For armor piercing, lately the goal has been to keep the caliber down, and increase mass and/or hardness with depleted uranium or tungsten, which are very dense and harder than lead.

In the civilian area, teflon tipped bullets (so-called cop-killer) made a big splash a while back, but it was mostly anti-gun hype, they were designed for law enforcement use, and never available to the public. They were designed to penetrate things like car doors, not kevlar.

The teflon was actually mostly to prevent excess wear on the barrel of the gun, since the bullet was made almost entirely from brass. No cop has ever been killed by the bullets so named (As far as anyone can tell). I'd imagine a diamond coated bullet would tear up a barrel in short order, and would be totally impractical.

An interesting factoid regarding expansion: hollow and soft tipped bullets are mostly banned in engagements of war by the Hague Peace Conferences, which the US didn't technically sign on to, but they follow this part anyway. The Geneva convention also bans "weapons that cause superfluous injury". I guess the point of war is to maim, not to kill.