Interlayer-assisted explosive welding of 5083Al/SS316 composite plates: Interlayer design and thermal stability

Abstract

To address the challenges of the narrow welding window and poor weldability between 5083Al aluminum alloy and SS316 stainless steel in explosive welding, this study employs an interlayer-assisted explosive welding to fabricate high-performance 5083Al/SS316 composite plates. Based on solubility calculations, a set of interlayer design criteria is proposed. Aluminum (Al), titanium (Ti), and nickel (Ni) were selected as interlayer materials for the fabrication of 5083Al/SS316 explosive composite plates. The effects of interfacial intermetallic compounds on the interface structure and properties of the composite plates are elucidated, and the thermal stability of the interfaces is investigated. The results indicate that no intermetallic compounds form at the 5083Al/1060Al interface in the three-layer 5083Al/1060Al/SS316 composite plate, while Al₃Fe is detected at the 1060Al/SS316 interface. In the four-layer 5083Al/1060Al/TA1/SS316 composite plate, AlTi and AlTi3 form at the 1060Al/TA1 interface and TiFe2 at the TA1/SS316 interface. In the five-layer 5083Al/1060Al/TA1/N6/SS316 composite plate, TiNi and TiNi3 are observed at the TA1/N6 interface, whereas no intermetallic compounds were detected at the N6/SS316 interface. The pull-off strength of the four-layer composite plate reaches 118 MPa, and that of the five-layer plate 147 MPa, with fracture occurring in both cases at the 5083Al/1060Al interface. The maximum service temperatures 300 °C and 350 °C for the four- and five-layer interfaces, respectively. Due to the intensified interlayer impact caused by the introduction of the Ni interlayer, the dislocation density at the 5083Al/1060Al interface in the five-layer composite plate is significantly higher than that in the four-layer counterpart. This high dislocation density hinders rearrangement, thereby suppressing recovery and recrystallization. Consequently, the five-layer composite plate exhibits enhanced interfacial thermal stability.