Accession Number : ADA581752


Title :   Friction Stir Weld Failure Mechanisms in Aluminum-Armor Structures Under Ballistic Impact Loading Conditions


Descriptive Note : Journal article


Corporate Author : CLEMSON UNIV SC


Personal Author(s) : Grujicic, M ; Pandurangan, B ; Arakere, A ; Yen, C ; Cheeseman, B A


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a581752.pdf


Report Date : Jan 2013


Pagination or Media Count : 14


Abstract : A critical assessment is carried out of the microstructural changes in respect of the associated reductions in material mechanical properties and of the attendant ballistic-impact failure mechanisms in prototypical friction stir welding (FSW) joints found in armor structures made of high-performance aluminum alloys (including solution-strengthened and age-hardenable aluminum alloy grades). It is argued that due to the large width of FSW joints found in thick aluminum-armor weldments, the overall ballistic performance of the armor is controlled by the ballistic limits of its weld zones (e.g., heat-affected zone, the thermomechanically affected zone, the nugget, etc.). Thus, in order to assess the overall ballistic survivability of an armor weldment, one must predict/identify welding-induced changes in the material microstructure and properties, and the operative failure mechanisms in different regions of the weld. Toward this end, a procedure is proposed in the present study which combines the results of the FSW process modeling, basic physical-metallurgy principles concerning microstructure/property relations, and the fracture mechanics concepts related to the key blast/ballistic-impact failure modes. The utility of this procedure is demonstrated using the case of a solid-solution strengthened and cold-worked aluminum alloy armor FSW-weld test structure.


Descriptors :   *ALUMINUM ALLOYS , *BALLISTICS , *FAILURE , *FRICTION WELDING


Subject Categories : Metallurgy and Metallography
      Fabrication Metallurgy
      Ballistics


Distribution Statement : APPROVED FOR PUBLIC RELEASE