To create transparent aluminum, Raytheon starts with a powdercomprised of aluminum, oxygen and nitrogen. This powder is molded andbaked the way a ceramic is baked. The powder liquefies and then coolsinto a solid, creating a rigid crystalline structure. The resultingaluminum alloy molecules are arranged as if still in liquid form.Polishing strengthens the material and makes it clear.
Apparently, the heating and handling involved makes the process forcreating transparent aluminum prohibitively expensive outside thesurreal budgets of defense contracting. The substance has been layeredonto bullet-proof glass in vehicle-window size prototypes. The goodnews for soldiers is that transparent aluminum-coated glass weighs halfas much and is half as thick as conventional bullet-proof glass, buthas the ability to stop anti-aircraft fire.
Source: blog.mindtribe.comAdded: 16 February 2009