About this Abstract |
| Meeting |
2026 AWS Professional Program
|
| Symposium
|
2026 AWS Professional Program
|
| Presentation Title |
Novel Resistance Spot Welding Technology for Dissimilar Aluminum to Galvanized Steel Joints with Improved Mechanical Properties |
| Author(s) |
Rakhi Bawa, Trey Soards, Antonio Ramirez, Jerry Gould, Olga Eliseeva |
| On-Site Speaker (Planned) |
Rakhi Bawa |
| Abstract Scope |
Dissimilar joining via resistance spot welding (RSW) has been long sought after in the automotive industry to improve energy efficiency by optimizing body-in-white vehicle designs. However, joining dissimilar alloy families such as the commonly used 6XXX series aluminum alloys and advanced high strength steels proves challenging with traditional RSW due to the formation of brittle Fe-Al intermetallic compounds (IMCs). The commonly used RSW technology in automotive manufacturing today is Medium Frequency-Direct Current (MFDC) power supplies, which convert three-phase AC power from the bus bar to a direct current pulse delivered at the tips. While efficiently automated and optimized for similar metal joining, the MFDC RSW process has a long cycle time (~500-1000 ms), which is detrimental to the growth of IMCs at dissimilar interfaces. As an alternative, a new technology for resistance spot welding has been developed which delivers a much shorter and higher current pulse to the sheets without the need for water-cooled electrodes. This Medium Frequency-Frequency Converter (MF-FC) technology uses a power supply designed to deliver a single DC pulse to the sheets with a pulse width of 5ms, drastically reducing the time at temperature experienced by the dissimilar interface; therefore, reducing diffusion and IMC growth. In this work, 6541-T4 Aluminum Alloy and Galvanized Dual Phase Steel with 600 Mpa UTS are joined using the MF-FC process. Parameter development is conducted with current range testing for 1 and 2 pulses with static mechanical tensile shear testing and cross tension testing evaluation methods. Normalized mechanical testing results show improvement over current MFDC RSW technology. Characterization via light optical microscopy reveals the nugget morphology, and characterization of the fracture surfaces and the phases forming at the interface via scanning electron microscopy provide insight into how these dissimilar materials interact during the short welding process. |
| Proceedings Inclusion? |
Undecided |