Microstructural Investigation and Evaluation of Mechanical Properties in Friction Stir Welded Joints

Abstract

With involvement of the United States Military in various places in the world, increased improvements in personnel and vehicle protection are needed. Traditionally, armoring techniques have performed well against particular threats; however, a new threat has emerged from improvised explosive devices (IEDs), which has exposed the vulnerability of the undercarriage of the vehicle to explosions. Various solutions have been proposed to combat this problem, such as implementation of a unibody construction of the chassis. While traditional joining techniques have shown promise, the variability in mechanical properties of the weldment can be costly and needs to be addressed. Friction Stir Welding (FSW) is a solid-state welding technique, which involves local softening of the material subjected to severe plastic deformation, coupled with a localized heat flux, creates a unique microstructure in and around the weld that is dependent on the FSW parameters. The current work involves the characterization of the microstructures that develop during FSW as it relates to the locally spatial mechanical properties in the weld zone. The microstructure will be characterized by using scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) techniques, which, when coupled with mechanical testing data, can be used to shed light on the spatial stress-strain behavior of the welded sample.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Aug 01, 2011
Accession Number
ADA558384

Entities

People

  • Brian Justusson

Organizations

  • United States Army Research Laboratory

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Friction Stir Welding
  • Grain Size
  • Heat Flux
  • Joints
  • Materials
  • Mechanical Engineering
  • Mechanical Properties
  • Mechanical Working
  • Microscopy
  • Microstructure
  • Tensile Strength
  • Tensile Testing
  • Test Methods
  • Welded Joints
  • Welding
  • Weldments
  • Welds

Fields of Study

  • Materials science

Readers

  • Materials Science and Engineering.
  • Reinforced Composite Materials
  • Structural Health Monitoring of Composite Structures.

Technology Areas

  • Microelectronics