Fundamental characterization of the additive friction stir-deposition process via two commercial aluminum alloys

Show simple item record

dc.contributor Brewer, Luke N.
dc.contributor Davami, Keivan
dc.contributor Doherty, Kevin J.
dc.contributor MacPhee, David W.
dc.contributor.advisor Allison, Paul G.
dc.contributor.advisor Jordon, James B. Phillips, Brandon James
dc.contributor.other University of Alabama Tuscaloosa 2021-07-07T14:36:53Z 2021-07-07T14:36:53Z 2021
dc.identifier.other u0015_0000001_0003793
dc.identifier.other Phillips_alatus_0004D_14408
dc.description Electronic Thesis or Dissertation en_US
dc.description.abstract Additive manufacturing is a rapidly growing industry with numerous technologies to suit a variety of applications. However, each application has its own inherent flaws and niches. Aluminum alloys are difficult for the more popular fusion-based additive manufacturing techniques due to the intense thermal gradients generating distortion and selective vaporization of alloying elements. To subjugate some of the issues, the solid-state Additive Friction Stir-Deposition (AFS-D) method was proposed to produce high quality, defect free aluminum deposits. This work investigates the process-structure-property relationships of two popular commercial aluminum alloys employed extensively by consumer, transportation, and defense industries. The first work on process-deformation characteristics of AA6061 were evaluated by producing microhardness profiles taken from the cross-section of builds to produce relationships between mechanical characteristics and machine parameters. Resulting average hardness values were plotted against the processing window and used to determine comparative samples for microstructural analysis. Electron backscatter diffraction and transmission electron microscopy was conducted to characterize the microstructural evolution of depositions. This study provides a succinct, multiscale characterization of as-deposited AFS-D AA6061 to expound the effect of the high-shear solid-state AM process. The subsequent investigation on AA6061 is the first investigation of the process-structure-property relationships of AFS-D in an overlapping, parallel raster deposit. In particular, the deposit produced in this work explores the influence of severe plastic deformation on the as-deposited microstructure and tensile response of material that overlaps in parallel layers at the outer edge of the tool. This study sought to determine the viability of producing large scale structural components larger than the track-width of the AFS-D tool. The final study quantifies the microstructural evolution and consequential tensile response of AA5083. A brief examination of the effect of AFS-D processing parameters was undertaken to determine preferential processing conditions for a larger, free-standing AA5083 structure. Optical and scanning electron microscopy evaluate the microstructural evolution of particles and grain morphology. Tensile properties were evaluated in the longitudinal and vertical build directions, and subsequent fractography discovered the influence of lubrication on the variable mechanical response. en_US
dc.format.extent 131 p.
dc.format.medium electronic
dc.format.mimetype application/pdf
dc.language English
dc.language.iso en_US
dc.publisher University of Alabama Libraries
dc.relation.ispartof The University of Alabama Electronic Theses and Dissertations
dc.relation.ispartof The University of Alabama Libraries Digital Collections
dc.relation.hasversion born digital
dc.rights All rights reserved by the author unless otherwise indicated. en_US
dc.subject Mechanical engineering
dc.title Fundamental characterization of the additive friction stir-deposition process via two commercial aluminum alloys en_US
dc.type thesis
dc.type text University of Alabama. Department of Mechanical Engineering Mechanical Engineering The University of Alabama doctoral Ph.D.

Files in this item

This item appears in the following Collection(s)

Show simple item record

Search DSpace


My Account