Abstract

Three-dimensional residual stress mapping of an aluminum 2024-T3 arcan specimen, butt-welded by the friction stir technique, was performed by neutron diffraction. Results indicate that the residual stress distribution profiles across the weld region are asymmetric with respect to the weld centerline, with the largest gradients in the measured residual stress components occurring on the advancing side of the weld, with the longitudinal stress, σL, oriented along the weld line, as the largest stress. Within the region inside the shoulder diameter, the through-thickness stress, σZ, is entirely compressive, with large gradients occurring along the transverse direction just beyond the shoulder region. In addition, results indicate a significant reduction in the observed residual stresses for a transverse section that was somewhat closer to the free edge of an Arcan specimen. Microstructural studies indicate that the grain size in the weld nugget, is approximately 6.4 microns, with the maximum extent of the recrystallized zone extending to 6 mm on each side of the weld centerline. Outside of this region, the plate material has an unrecrystallized grain structure that consists of pancake shaped grains ranging up to several mm in size in two dimensions and 10 microns in through-thickness dimension.

1.
James, M., Mahoney, M., and Waldron, D., 1999, “Residual Stress Measurements in Friction Stir Welded Aluminum Alloys,” Proceedings of the 1st International Symposium on Friction Stir Welding, June, Thousand Oaks, CA.
2.
Sutton, M. A., Yang, B., Reynolds, A. P., and Taylor, R., 2000, “Preliminary Studies of Mixed Mode Fracture in 2024-T3 Friction Stir Welds,” Best of Aeromat Session, ASM Materials Solutions Conference and Exhibition, St. Louis, MO, October 9–12.
3.
Jata
,
K. V.
, and
Semiatin
,
S. L.
,
2000
, “
Continuous Dynamic Recrystallization During Friction Stir Welding of High Strength Aluminum Alloys
,”
Scr. Mater.
,
43
, pp.
743
749
.
4.
Rhodes
,
C. G.
,
Mahoney
,
M. W.
,
Bingel
,
W. H.
,
Spurling
,
R. A.
, and
Bampton
,
C. C.
,
1997
, “
Effects of Friction Stir Welding on Microstructure of 7075 Aluminum
,”
Scr. Mater.
,
36
, No.
1
, pp.
69
75
.
5.
Murr, L. E., Liu, G., and McClure, J. C., 1997, “Dynamic Recrystallization in Friction-Stir Welding of Aluminum Alloy 1100,” J. Mater. Sci. Lett., No. 16, pp. 1801–1803.
6.
Wang, D.-Q., Hubbard, C. R., and Spooner, S., “Residual Stress Determination for a Ferritic Steel Weld Plate,” ORNL, TM1999/141.
7.
Sutton, M. A., Abdelmajid, I., Zhao, W., Wang, D.-Q., and Hubbard, C. R., Basic Studies of Welds in a Tank Car Steel: Residual Stress Measurements and Weld Characterization for TC-128B Plate Steel,” accepted to be published in Transaction of Transportation Research Board.
8.
Xu, S., Deng, X., Reynolds, A. P., and Seidel, T. U., “Finite Element Simulation of Material Flow in Friction Stir Welding,” Sci. Technol. Weld. Joining (in press).
9.
Nunes, A. C., Jr., Bernstein, E. L., and McClure, J. C., “A Rotating Plug Model for Friction Stir Welding,” submitted to the Welding Journal Research Supplement (in review).
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