Assessing LOX Compatibility for Aluminum-Lithium Alloys

High strength lithium bearing aluminum alloys offer a significant cost saving potential for application to advanced launch and space vehicles. Three well developed alloys, Al-Li 2090, Al-Li 8090, and Weldalite 049, were evaluated for potential application to the large liquid oxygen and hydrogen tanks for the Advanced Launch System. A series of oxygen compatibility tests evaluation was conducted which included the mechanical impact test in liquid and gaseous oxygen, as per NASA 8060.1B, and the promoted combustion test in pressurized gaseous oxygen. Test results indicated that these alloys were in the same fire hazard category as the Aluminum 2219 currently being used in the external propellant tank of the US Space Shuttles. The test results also highlighted a need for changing the current mechanical impact test standards.