Novel interlayer-adhesive hybrid joining technique for resistance spot welding of dissimilar aluminum-steel sheet materials
Year: 2026
Type: article
Abstract: The push for lightweighting in automotive manufacturing has necessitated the introduction of dissimilar metal joints in the automobile body, often joints between aluminum and steel. Resistance spot welding (RSW), while a well-established, cost-effective and rapid welding process, experiences problems when welding aluminum-steel joints due to the formation of brittle intermetallic compounds, which degrade joint integrity. However, a previous work has shown that stainless steel interlayers can effectively inhibit excessive growth of brittle Fe-Al intermetallic compounds during RSW. This work explores the feasibility of a novel hybrid joining concept where RSW is combined with adhesive bonding together with a 316L stainless steel interlayer deposited via cold spray. Both 1.8-mm-thick extruded 6063-T6 and 2.2-thick cast aluminum sheet materials were welded to 1.5-mm-thick Al-Si-coated Usibor 1500 AS150 press-hardened steel (PHS). Weld joints were characterized with light optical microscopy and scanning electron microscopy, which revealed the formation of a thinner Fe-Al intermetallic layer between the aluminum substrate and the 316L interlayer compared with welding aluminum directly to PHS. Quasistatic tensile testing was performed in the lap-shear configuration. Both the interlayer-only and hybrid approaches showed improved tensile strength, achieving 2.9 kN and 17 kN maximum tensile force compared with 0.92 kN achieved by the reference extruded aluminum-steel RSW specimens. This work shows that this joining technique is a promising approach for providing a fixture point for automotive components prior to curing of the adhesive.
Source: Welding in the World
Institutions: Swerim, Tampere University, University of Tampere
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,290
Funder: VINNOVA
OpenAlex ID: W7123350929