Accession Number : ADA258121


Title :   Evaluation of 8090 and Weldalite-049 Aluminum-Lithium Alloys


Corporate Author : ARMY LAB COMMAND WATERTOWN MA MATERIALTECHNOLOGY LAB


Personal Author(s) : Holmes, Thomas M ; Chin, Ernest S ; Huang, Paul J ; Pasternak, Robert E


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a258121.pdf


Report Date : Sep 1992


Pagination or Media Count : 39


Abstract : Aluminum-lithium (Al-Li) alloys with their high strength, high stiffness, and low density continue to be of great interest to the aerospace industry. The microstructure, properties and fracture of 8090-T8771 and WeldaliteTM 049-T8 Al-Li alloys were studied at MTL in participation with a cooperative round robin sponsored by the Air Force Advanced Aluminum Alloy Test Program. Both 8090 and Weldalite Al-Li alloys demonstrate superior strength to weight ratios compared to the 2519 and 5083 aluminum armor alloys. The 8090 alloy possesses comparable mechanical and ballistic properties to 2519, while providing an 8% reduction in density. The Weldalite has a comparable density to 2519 but demonstrates improvements of over 25% in yield strength, ultimate tensile strength and fracture toughness. Both Al-Li alloys display significantly improved axial fatigue properties over 2519. Under static loading, both materials display mixed modes of transgranular shear, microductility and intersubgranular failure. Under ballistic testing, both alloys display mixed modes of dynamic failure by plugging, spalling and delamination. Whether the goal is to reduce weight or to improve strength, Al-Li alloys offer significant potential for replacing alloys such as 2519 and 5083 as lightweight, high-strength structural armor materials.


Descriptors :   *TEST AND EVALUATION , *ALLOYS , *LITHIUM , *ALUMINUM , SHEAR PROPERTIES , ARMOR , DENSITY , RATIOS , MECHANICAL PROPERTIES , TENSILE STRENGTH , AIR FORCE , MICROSTRUCTURE , INDUSTRIES , ALUMINUM ALLOYS , AIR , DYNAMICS , MATERIALS , LOADS(FORCES) , STIFFNESS , FAILURE , PLUGGING , SPALLATION , DELAMINATION , BALLISTICS , STATICS , AEROSPACE INDUSTRY , YIELD STRENGTH , LOW DENSITY , DUCTILITY , FATIGUE , LIGHTWEIGHT , YIELD , WEIGHT , HIGH STRENGTH , FRACTOGRAPHY , REDUCTION , TOUGHNESS


Subject Categories : Properties of Metals and Alloys
      Fabrication Metallurgy
      Ballistics


Distribution Statement : APPROVED FOR PUBLIC RELEASE