Science a GoGo's Home Page Forums General Discussion General Science Discussion Forum Transparent Metal

Hi all,
I realy hope this is the correct channel because I could see where this could be a sci fi question as well, but here goes; Is it probable for there to be a transparent metal used for windshields in the future? I was watching a television show where they discussed that it would not be possible for space ships to have large windshields since glass is a form of liquid and would not be able to hold its shape in space, and they said that it could be done with a plasma window, but I doubt any would be willing to go into space with nothing but a plasma window between them and space, so I was wondering if a metal could be made to look transparent or if there were another element like silicon to do the job.

Why not use cameras? You don't need a transparent windshield to see what is in front of you.

Could we really use our natural ability for peripheral vision with cameras?

Transparent metal has always been a dream (even on Star Trek) and there is a bit of research going on at the moment. However, so far, according to the metallurgist in my family, the best attempts so far look like shadow-filled translucent glass and have a high number of pores. Personally I have no idea what that would mean, but it doesn't sound good enough for space travel yet.

With camers wouldn't you still need glass?

There is no such thing as a transparent metal.
Not yet anyway. Although you can mix quite a lot of Lead (by weight) into molten glass, and it still remains clear.
Though thats not quite the same.

Your surmise that Glass is a super cool liquid is correct.
It is a very unique substance. Many unique additives have yet to be tried and tested.

Being a supercooled liquid, it will creep towards gravity, noticably taking 50+ years for its deformation to become apparent. Very old window glass often shows this effect.

Helicopter windows use a type of Polycarbonate 'plexiglass'
Its strong, but I wouldnt recommend it for a Spacecraft window either.
A 5" or 6" circular window made up of a triple layer of
'Makrolan' (which is bandit proof) might be Ok for a space window? But it would have to be coated against UV light, and probably fixed in place using a curing Silicon rubber. (No drill holes to weaken it)

There is a very very strong clear Ceramic, made from Aluminium Oxynitride, now being evaluated by the Military powers. It is genuinely bullet proof, heat proof, and "glass clear". But it costs a lot of money, as it has to be sintered to shape in a special oven.


The USA Co 'Raytheon' produced pure Sapphire bouls, in conjunction with the Swiss, over 40 years ago. The Swiss developed the method for producing perfect synthetic sapphires for the watch industry 50 years ago, by running an RF
heater, repeatedly along a vertical rod of Alumina powder.
(this production method was still a well kept secret, up until about 25 years ago)
A pure Sapphire globule formed at the top, while the impuritys collecteed at the bottom end. It took hundreds of continuous
(very slow) RF runs, always keeping a few inches of the tube molten, which allowed the pure Sapphire to gravitate upwards.
Sapphire of course is extremely hard, but it is not technically possible to make it into a flat window sheet.

Here is a news Release from the Ratheon website, (no date given)

**************************************************

Raytheon and Surmet Corp. to Develop and Market New Aluminum Oxynitride (ALON(R)) Products for Commercial, Defense and Homeland Security Applications

LEXINGTON and BURLINGTON, Mass., July 25 /PRNewswire/ --
Raytheon Company (NYSE: RTN) has signed an agreement with Surmet Corp., a pioneer and technical leader in the Advanced Materials field, that allows Surmet Corp. to develop Raytheon's aluminum oxynitride (ALON(R)) manufacturing and process technologies. Surmet Corp. will initially focus on marketing ALON(R) to the semiconductor equipment, lighting, bio-medical, bar code scanner, defense and homeland security industries.

Raytheon developed ALON(R), which has the physical appearance of glass but has phenomenal ballistic properties, as an alternative material for sapphire for missile seeker window applications.
ALON(R) products possess excellent light transmission, impact resistance and structural stability over a wide range of temperatures.

"ALON(R) was developed as advanced military material and kept as a well guarded secret," said Timothy C. Davis, president and chief executive officer of Surmet Corp. "It has never before been produced, marketed and available for commercial applications. With material properties similar to sapphire but with far lower costs, ALON(R) could be a replacement for many materials including alumina, quartz as well as sapphire."

"Using patented and proprietary plasma enhanced PVD and CVD processes, Surmet has developed advanced ceramic, metal and composite coatings that significantly improve the performance characteristics of many materials," said Dr. Suri Sastri, founder and chairman of Surmet Corp.
"ALON(R) provides tremendous synergy for the technologies we have developed over the past 20 years. We are very excited to be acquiring rights to commercialize ALON(R) and working with Raytheon to commercialize this advanced material."

"This strategic relationship is the latest example of how Raytheon's leading-edge defense technology can be utilized in commercial markets to create a long term competitive advantage for our partner," said Glenn Lenzen, vice president of Raytheon's corporate Intellectual Property and Licensing
department. "Surmet will be able to utilize ALON(R) in a variety of applications and industries that would significantly benefit from the technical and cost characteristics."

Raytheon's Intellectual Property and Licensing department teamed with Raytheon Commercial Ventures Inc. (RCVI) to form the new partnership with Surmet Corp. RCVI was established in February 2001 to create a "commercialization engine" within Raytheon and since then Raytheon has spun technology into five companies where it has retained an equity interest

Surmet Corp., of Burlington, Mass., is an industry leader in surface metallurgy and engineered coatings.

Based in Lexington, Mass., Raytheon Company is a global technology leader in defense, government and commercial electronics and business and special mission aircraft.

Amy Hosmer
781.860.2423
Raytheon Company

Timothy C. Davis
781.272.3969
Surmet Corp.

MAKE YOUR OPINION COUNT - Click Here
http://tbutton.prnewswire.com/prn/11690X57294671

SOURCE Raytheon Company



Web site: http://www.raytheon.com


CONTACT: Amy Hosmer, of Raytheon Company, +1-781-860-2423; or Timothy C. Davis, +1-781-272-3969, Surmet Corp.
.

Its interesting that there is work going on to develop a tranparent 'Metallic'Glass. Almost nothing is impossible these days.
Getting back to one of the original questions, that Rallem ask.
ie. Large glass windshields for Spaceships.

I am sure large glass domes are out, even using a laminated architectural glass would be unsafe.

However, I forgot that the International Space station does have some glass portholes, using laminated glass.
I have no idea of their total thickness, I'm guesstimating, not more than a 3/4" thick laminate, probably thinner? Since it only has to support an internal pressure of one atmosphere.
Micrometeorites would cause no problems. Some years back the Astronauts complained that their viewing window had developed a hazy bloom, making it difficult to get some good camera shots.

I dont think the reason for that, was ever given. My guess is that it might have beeen a combination of 'outgassing' of the laminating film, together with UV light?

But if its thick enough, glass is very strong. The Ocean Bathyscape that can descend to +3 miles deep? Is a case in point, it has a large viewing window. Here weight is not a problem.

At the other extreme, the thin accurate glass Hubble lenses, are protected from micometeorite erosion by an Aluminium tube.

Thank you for al of that great information.