Abstract
Ultrasonic spot welding (USW) was employed to join AA7075-T6 and casting Al alloy A380. Under a constant welding power, the influence of the welding time duration (from 1 s to 3 s) on peak temperature, microstructure, hardness, and mechanical strength of the joints were studied. It was found that the peak temperature increased with welding time. A sound solid-state metallurgical bonding was obtained at the joint interface. The cracks occurred at the edge of the joints were eventually eliminated as the welding time increased. A layer of refined grains formed in A380 adjacent to the bonding line. Hardness reduction occurred in AA7075 at the joint interface and the degree of hardness reduction and the volume increased with the peak temperature. By increasing welding time, lap shear tensile tests show that the peak load increased from 5.3 kN to 6.55 kN. The corresponding interfacial shear strength ranged from 96.29 MPa to 99.72 MPa, lower than the shear strength of both base materials (331 MPa for AA7075 and 185 MPa for A380). All joint samples exhibited interfacial fracture after lap shear tensile testing, with a thin layer of A380 remnant attached to AA7075 at the center of the fractured surface.
| Original language | English |
|---|---|
| Pages (from-to) | 126-133 |
| Number of pages | 8 |
| Journal | Journal of Manufacturing Processes |
| Volume | 110 |
| DOIs | |
| State | Published - Jan 31 2024 |
Funding
This research was financially sponsored by the US Department Energy Vehicle Technologies Office, as part of the Joining Core Program. Oak Ridge National Laboratory (ORNL) is managed by UT-Battelle LLC for the US Department of Energy under Contract DE-AC05-00OR22725. That authors would like to thank Ford Company for the supply of A380 casting plates. Notice: This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, 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. DOE 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 ). This research was financially sponsored by the US Department Energy Vehicle Technologies Office , as part of the Joining Core Program. Oak Ridge National Laboratory (ORNL) is managed by UT-Battelle LLC for the US Department of Energy under Contract DE-AC05-00OR22725 . That authors would like to thank Ford Company for the supply of A380 casting plates.
| Funders | Funder number |
|---|---|
| Ford Company | |
| U.S. Department of Energy | DE-AC05-00OR22725 |
| Oak Ridge National Laboratory | |
| UT-Battelle |
Keywords
- Dissimilar materials joining
- Grain refinement
- Ultrasonic spot welding of metals