Composite metal foams

[bernorange 8359]

I posted a thread about them roughly a year ago on the old board:

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Foam body armor? Even armor-piercing bullets cannot get through this foam.

And the foam doesn’t just stop bullets. It destroys them…this foam decimates bullets into dust.

North Carolina State University Professor Afsaneh Rabiei led the team that created the amazing foam.

This is not ordinary foam like the kind used for shaving, for example. This is a special type of foam called composite metal foams, or CMF.

The military and law enforcement could use this kind of foam for advanced, ultra light body armor to protect personnel.

And this research team has other foams up its sleeve that have the potential to keep military and first responders safe from radiation and extreme heat too.
...
This foam is able to stop and block X-rays. In tests, it can even protect against various forms of gamma rays.
...

http://www.foxnews.com/tech/2017/02/23/this-foam-stops-bullets-cold-and-pulverizes-them-to-dust.html

The tech was developed at NC State:

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...
The researchers found that the high-Z foam was comparable to bulk materials at blocking high-energy gamma rays, but was much better than bulk materials – even bulk steel – at blocking low-energy gamma rays.

Similarly, the high-Z foam outperformed other materials at blocking neutron radiation.

The high-Z foam performed better than most materials at blocking X-rays, but was not quite as effective as lead.

“However, we are working to modify the composition of the metal foam to be even more effective than lead at blocking X-rays – and our early results are promising,” Rabiei says. “And our foams have the advantage of being non-toxic, which means that they are easier to manufacture and recycle. In addition, the extraordinary mechanical and thermal properties of composite metal foams, and their energy absorption capabilities, make the material a good candidate for various nuclear structural applications.”

The paper, “Attenuation efficiency of X-ray and comparison to gamma ray and neutrons in composite metal foams,” is published in Radiation Physics and Chemistry. Lead author is Shuo Chen, a recent Ph.D. graduate at NC State. The paper was co-authored by Mohamed Bourham, a professor of nuclear engineering at NC State. The work was supported by DOE’s Office of Nuclear Energy under Nuclear Energy University Program grant number CFP-11-1643.

https://news.ncsu.edu/2015/07/rabiei-foam-rays-2015/

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... The bullet in the video is a 7.62 x 63 millimeter M2 armor piercing projectile, which was fired according to the standard testing procedures established by the National Institute of Justice (NIJ). And the results were dramatic. (The video can also be found at https://www.youtube.com/watch?v=lWmFu-_54fI).

“We could stop the bullet at a total thickness of less than an inch, while the indentation on the back was less than 8 millimeters,” Rabiei says. “To put that in context, the NIJ standard allows up to 44 millimeters indentation in the back of an armor.” The results of that study were published in 2015. ...

https://news.ncsu.edu/2016/04/metal-foam-tough-2016/

More: https://news.ncsu.edu/2016/03/rabiei-heat-2016/

The author of the FoxNews article from a year ago (mentioned above) has a new article about it:

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... The M1 Abrams Main Battle Tank, for example, weighs in at more than 60 metric tons, so every pound matters.

Rolled homogeneous armor steel plate is frequently used for tanks and armored vehicles. The new foam has potential to provide enhanced protection — three times lighter than the current armor approach.

Here’s a practical example: A future vehicle could theoretically be kitted out with just 4 tons of CMF, rather than 12 tons of the traditional armor.

This means approximately the same protection, but with armor that is 8 tons lighter.

Imagine what an impact lighter weight could have on future combat vehicles. This remarkable foam would then be providing yet another whole set of advantages, from faster speeds through to more maneuverabilty and agility.

The Army is considering next gen replacements for the M1 Abrams main battle tank and M2 Bradley infantry fighting vehicle, both of which will require state of the art, groundbreaking armor.

http://www.foxnews.com/tech/2018/04/09/new-foam-armor-for-tanks-can-pulverize-enemies.html

[El Diablo 4232]

There's a good bit of basic info on metal foams in this Wiki entry.

https://en.wikipedia.org/wiki/Metal_foam

I remember reading about 20 years or so ago about the auto industry attempting to use metal foams as a fuel source. I don't remember the details but the basic idea was that you would have a tank full of the metal foam and then run a fluid thru it that would cause the metal to release atoms like hydrogen, something that could be burned as fuel. Of course the source metal would become depleted over time and there were many other roadblocks but the idea was intriguing at the time.

[thunderlounge 7813]

Sure could be a lot of practical uses for that stuff. Aside from just armors. 

Hurricane shutters, tornado shelters, the list goes on and on. 

[El Diablo 4232]

Unfortunately the reality is there's no economic incentive to do a lot of things that we CAN do. One of the reasons I love to read NASA TechBriefs is for weird, off the wall technology that may or may not have any practical applications. The cool part there is it's available if you find/figure out a way to successfully monetize it.

Edited April 14, 2018 by El Diablo

[HOOK'EMHOOAH 1610]

Armor is great, but the real reason R&D monies are being put into it for armor is because it stands to cut down on the amount of payout life insurance companies will have to do thereby increasing their profit margins. In the end, it will also save lives... so i guess thats a nice side bonus.