Abstract
2219-T87 is a precipitation hardenable aluminum-copper alloy which sees wide use in structural aerospace components. Thick panels of this alloy are joined via self-reacting friction welding (SRFSW); however, this thermomechanical process can result in significant loss of the alloy’s strengthening precipitates and large residual stresses which are detrimental to mechanical behavior and performance. High-resolution maps of the residual strain and stress states along the normal, transverse, and longitudinal directions of 2219-T87 SRFSW were obtained using neutron diffraction measurements. Residual stress had the highest tensile value in the heat-affected zone (HAZ) and the largest compressive stress in the base metal region of the normal and transverse directions. Line profile residual stress distributions displayed an “M”-shaped distribution in each direction with the longitudinal direction being the most pronounced while 2D residual stresses displayed an hourglass-shaped pattern. Average maximal longitudinal residual stress values ranged from 60.6 to 85.6% of yield. Microhardness testing across the transverse weld section produced a “V”-shaped curve with slight hardness recovery in the stir zone. Maximal and minimal microhardness values were observed in the base metal (154 HV) and thermomechanically affected zone (82 HV), respectively. Microstructural evolution was recorded using optical microscopy and showed decreasing grain size from the HAZ to the stir zone.
| Original language | English |
|---|---|
| Pages (from-to) | 4149-4159 |
| Number of pages | 11 |
| Journal | Journal of Materials Engineering and Performance |
| Volume | 33 |
| Issue number | 8 |
| DOIs | |
| State | Published - Apr 2024 |
Funding
The authors would like to acknowledge partial support though the Manufacturing and Materials Joining Innovation Center (MaJIC), University of Tennessee, Knoxville site. MaJIC is funded by the National Science Foundation (NSF) through the Industry/University Cooperative Research Center (I/UCRC) program award number IIP 1822186. This research used resources at the High Flux Isotope Reactor a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. The authors would like to thank Kevin Sisco for his contribution and assistance in microhardness testing. This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the US Department of Energy. The US Government retains and the publisher, by accepting the article for publication, acknowledges that the US Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).
Keywords
- aerospace
- aluminum
- metallography
- nondestructive testing
- residual stress
- welding