Aluminium oxynitride (AlON) is a transparent ceramic composed of aluminium, oxygen and nitrogen. It is marketed under the name ALON and described in U.S. Patent 4,520,116. The material remains solid up to 1,200 °C (2,190 °F), and is harder than glass. When formed and polished as a window, the material currently (2005) costs about US$10 to US$15 per square inch (~ US$20,000/m²).

It is currently the crucial outer layer of experimental transparent armor being considered by the US Air Force for the windows of armored vehicles. Other applications include semiconductors and retail fixtures.

Objects are usually formed from pressed, cast or molded powder. The formed objects are then densified by heating in an oven, and polished until transparent. The polishing substantially improves the armor's impact resistance.

[edit] See also

• Transparent alumina
• Transparent aluminium

[edit] References

• Sales (2003) (.PDF). ALON Optical Ceramic. Surmet Corporation. http://www.surmet.com/docs/Product_sheet_ALON.pdf. Retrieved 2009-01-09. 
• Air Force testing new transparent armor by Laura Lundin, Air Force Link, October 17, 2005, retrieved June 25, 2008

[edit] External links

• ALON product page
• Aluminum Oxynitride Spinel (ALON): A Review (Storming Media)
• Raytheon and Surmet Corp. to Develop and Market New Aluminum Oxynitride (ALON(R)) Products for Commercial, Defense and Homeland Security Applications (PRnewswire.com/alunet.net) Raytheon press release