DIA Report Reveals Military Interest in Metallic Glasses for Aerospace

The Defense Intelligence Agency reference document DIA-OS-0911-012, dated 14 December 2009 with a reissue date of 1 December 2009, was prepared under the Advanced Aerospace Weapon System Applications (AAWSA) Program, one in a series of advanced technology reports produced in FY 2009. Its subject is not propulsion or sensors but materials: metallic glasses, and whether they can serve as structural materials in aerospace vehicles. The report's central assessment is a trade-off.

Metallic glasses are amorphous metals that lack crystalline order. Because dislocations cannot exist in an amorphous structure, the strength of amorphous alloys can approach theoretical limits based on the inherent strength of atomic bonds. The document states that aluminum-based metallic glasses can be two or three times stronger than conventional crystalline high-strength aluminum alloys, and that the best iron-based alloys reach approximately 4 GPa, again two or three times greater than conventional high-strength steels.

That same absence of crystalline…