Accession Number : ADA583559


Title :   Microstructural Characterization of Friction Stir Welded Aluminum-Steel Joints


Descriptive Note : Master's thesis


Corporate Author : WASHINGTON STATE UNIV PULLMAN


Personal Author(s) : Patterson, Erin E


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a583559.pdf


Report Date : Aug 2013


Pagination or Media Count : 115


Abstract : This work focuses on the microstructural characterization of aluminum to steel friction stir welded joints. A lap weld configuration, coupled with scribe technology used for the weld tool, have produced joints of adequate quality, despite the significant differences in hardness and melting temperatures of the alloys. Common to friction stir processes, especially those of dissimilar alloys, are microstructural gradients including grain size, crystallographic texture, and precipitation of intermetallic compounds. Because of the significant influence that intermetallic compound formation has on mechanical and ballistic behavior, the characterization of the specific intermetallic phases and the degree to which they are formed in the weld microstructure is critical to predicting weld performance. This study used electron backscatter diffraction, energy dispersive spectroscopy, optical and scanning electron microscopy, and Vickers micro-hardness indentation to explore and characterize the microstructures of lap friction stir welds between 6111-T4 aluminum and dual phase galvannealed steel, as well as an applique 6061-T6 aluminum armor plate alloy and a wrought homogeneous armor plate steel alloy.


Descriptors :   *ALUMINUM , *STEEL , *WELDED JOINTS , ALLOYS , BACKSCATTERING , BALLISTICS , CONFIGURATIONS , CRYSTALLOGRAPHY , ELECTRON DIFFRACTION , ELECTRON MICROSCOPY , ENERGY , FRICTION , GRADIENTS , GRAIN SIZE , HARDNESS , INTERMETALLIC COMPOUNDS , JOINTS , MECHANICAL PROPERTIES , MELTING , MICROSTRUCTURE , OPTICAL PROPERTIES , PHASE , PRECIPITATION , QUALITY , SCANNING ELECTRON MICROSCOPES , SPECTROSCOPY , TEMPERATURE , THESES , TOOLS , WELDS


Subject Categories : Fabrication Metallurgy


Distribution Statement : APPROVED FOR PUBLIC RELEASE