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Title: Neutron diffraction studies of welds of aerospace aluminum alloys

Conference ·
OSTI ID:381757
;  [1]; ; ;  [2]
  1. Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science and Engineering
  2. Oak Ridge National Lab., TN (United States)

Neutron diffraction and electron microscopy were done on residual stress in various regions comprising variable polarity plasma arc welds of alloys 2219 (Al-6.3Cu) and 2195 (Al-4.0Cu-1.0Li-0.5Mg-0.5Ag). Results indicate that lattice parameter changes in the various weld regions may be attributed to residual stresses generated during welding, as well as local changes in microstructure. Distribution of longitudinal and transverse stress of welded panels shows peaks of tension and compression, respectively, within the HAZ and corroborate earlier theoretical results. Position of these peaks are related to position of minimum strength within the HAZ, and the magnitude of these peaks are a fraction of the local yield strength in this region. Weldments of alloy 2195-T8 exhibited higher peak residual stress than alloy 2219-T87. Comparison of neutron diffraction and microstructural analysis indicate decreased lattice parameters associated with the solid solution of the near HAZ; this results in decreased apparent tensile residual stress within this region and may significantly alter interpretation of residual stress measurements of these alloys. Considerable relaxation of residual stress occurs during removal of specimens from welded panels and was used to aid in differentiating changes in lattice parameters attributed to residual stress from welding and modifications in microstructure.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
AC05-96OR22464
OSTI ID:
381757
Report Number(s):
CONF-961017-11; ON: DE96015321
Resource Relation:
Conference: American Society of Mechanical Engineers (ASME) and Metals materials week, Cincinnati, OH (United States), 6-10 Oct 1996; Other Information: PBD: [1996]
Country of Publication:
United States
Language:
English