Scientists use laser to create black metal

[phantom power]

Two useful applications that come to my mind:

1) thermal solar capture

2) catalyst substrate

ROCHESTER, N.Y., Nov. 21 (UPI) -- U.S. scientists say they have created a laser technology that can change the properties of nearly any metal and render it, literally, black.

"We've been surprised by the number of possible applications for this," said Chunlei Guo, University of Rochester assistant professor of optics and lead investigator. "We wanted to see what would happen to a metal's properties under different laser conditions and we stumbled on this way to completely alter the reflective properties of metals."

The process involves an ultra-brief, ultra-intense beam of light called a femtosecond laser pulse. The laser burst lasts only a few quadrillionths of a second; a femtosecond is to a second what a second is to about 32 million years, the scientists explained.

During its brief burst, the laser unleashes an immense amount of power onto a spot the size of a needlepoint. That intense blast forces forms nanostructures that both dramatically increase the area of the surface and capture radiation.

Guo's research team tested the absorption capabilities of the black metal and confirmed it can absorb virtually all the light that falls on it, making it pitch black.

http://www.sciencedaily.com/upi/index.php?feed=Science&article=UPI-1-20061121-15094700-bc-us-blackmetal.xml

[iconoclastic cat]

1. Cool!

[Drum]

2. lol!

:P

[grizmaster]

3. interesting

too bad the article doesn't give much info. For instance, how much area becomes black from the pinpoint blast.

[seriousstan]

5. Microscale would imply pinpoint especially since the structures are nano.

Microscale periodic ordering of random surface nanostructures induced

by femtosecond laser pulses on metals

A.Y. Vorobyev, V.S. Makin, and C. Guo, submitted to J. Appl. Phys. (2006).

[grizmaster]

6. ask and ye shall receive

thanks

[Dudley_DUright]

8. You could always raster the beam across a surface while pulsing

the laser. I was just talking about femtosecond lasers in my optics class the other day. This is a nice application I will have to make sure I mention.

[Nihil]

11. Hmmm ... image-printing metal itself rather than just inking it?

That could make for a resilient photograph ...

Alternatively, if the "point" is scanned at a faster rate, less of the
surface will be blackened so you will get various shades of grey.
If you did this on an iron-rich base, you could end up with a grey car
that gradually shaded to brown then orange as it rusted!

Bake the bodyshell after the desired exposure then apply a clear coating.
Mind you, it would be a real bugger to match with a re-spray after denting
it ...

:-)

[leveymg]

4. In a few decades, they'll have a military application for this.

True stealth.

[bananas]

10. They already do

but it's a secret, so I can't tell you.

[Ian David]

7. Ship.... Sun...

"Every time I try to operate one of these weird controls, which is labeled black on a black background, a small black light lights up black to let you know you’ve done it!"

[phantom power]

9. Wild colour scheme!

:rofl:

[Canuckistanian]

12. Solar heat collectors!

I made a solar water heater a few years back using serpentine copper pipes in a black thermal mass metal plate.

But since copper and metals don't absorb a lot of heat, I had to paint it black using a high-heat enamel. But this reduces the efficiency, since the paint doesn't transfer the heat readily to the pipe underneath.

With this process, it looks like not only is there a good thermal conductivity, but also increased surface area. Good news.

There's already a process to make metals black (I think it's called nitrification), but it's very expensive.