Jin;
Aluminum oxide is hard and very strong but it is brittle like most ceramics.
You can grind it but that's about all. The stuff is formed-to-size as "green
tape" ans then vitrified in a VERY high temperature process. Kyocera is
probably the biggest supplier of alumina products. Coors (yep, the same
guys) used to make it too, but I don't know if they are still in the
ceramics business these days.
We (Texas Instruments) use it for making a few older hybrid circuits
(electronics). Conductor pastes of metallic gold, cermet resistor pastes and
glass pastes are silkscreened on a flat alumina substrate and then fired at
high temperature-- sort of like a ceramic printed circuit board.
We sometimes also use beryllium oxide where higher thermal conductivity is
required.
Regards, Neil Tucson, AZ
-----Original Message-----
From: Waldron, James [mailto:James.Waldron@CWUSA.COM]
Sent: Thursday, May 02, 2002 11:24 AM
To: land-speed@autox.team.net
Subject: RE: Transparent Aluminum
But this ceramic is not going to have the malleable characteristics of metal
(bend, stretch, form, weld, etc.) is it? I know that aluminum oxide is very
hard (3rd only to diamond and tantalum-di-oxide(?)) Any information on
structural properties (tension, torsion), and what about radar reflectivity?
(See through stealth?)
(A couple of years ago at Oshkosh they had a Stealth Fighter on display. At
one point when a thunderstorm threatened and they towed the fighter to a
hangar for protection, but the captain stayed at the display site to answer
questions. When asked where the stealth fighter was he casually gestured
over his shoulder and said, "Right there.")
Thanks,
Jim.
-----Original Message-----
From: Albaugh, Neil [mailto:albaugh_neil@ti.com]
Sent: Thursday, May 02, 2002 12:18 PM
To: 'Robert Jepson'; land-speed@autox.team.net
Subject: RE: Transparent Aluminum
Note that this is alumina (Al2O3)-- a ceramic, not aluminum (Al) metal.
Alumina is chemically related to sapphire; both are hard, strong, good
electrical insulators and have decent thermal conductivity. Sapphire is
transparent, 99% pure alumina is normally pure white.
Hard anodizing is a neat coating, especially when the pores are sealed with
micron- sized Teflon!
Regards, Neil Tucson, AZ
-----Original Message-----
From: Robert Jepson [mailto:robere@xensei.com]
Sent: Thursday, May 02, 2002 4:29 AM
To: land-speed@autox.team.net
Subject: Transparent Aluminum
http://www.rense.com/general20/transparentalum.htm
Kinda like aluminum anodized all the way through; years ago some M.I.T.
guys brought the idea of hard anodizing to my grandfather's (big)
plating shop, where they developed the technique. At the time they
thought they might be able to eventually penetrate the whole piece with
resulting 70 Rockwell (?) oxide, but only got in .001 or so.....
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