Abstract:
Considering the difficulties of low strength and limited application of aluminum-steel joining, a wire-based friction stir additive manufacturing method was proposed and utilized on the aluminum-steel transition joints. 5B06 aluminum alloy wires and 3 mm 316L stainless steel sheets were used as feedstock and substrate, respectively. The process was conducted with a laser texturing method assisting, and manufactured at a depositing efficiency of 3.0 kg/h with 1.0 mm thickness of each layer. The wires were thermo-plasticized and filled into the textured groove. No defect was observed along the interface. Metallurgical bonding was achieved by Al/Fe intermetallic compounds (IMCs) layers with a thickness of 1.8 μm. The shear strength of the joint reached 110.0 MPa ± 4.7 MPa., which increased by 18% relative to the joints with untreated surfaces. Aluminum alloys and IMCs (Fe
2Al
5 and Fe
4Al
13) were noticed on the fracture of the steel side, indicating that sound bonding was achieved by mechanical and metallurgical joining. The fracture mode of the joints was tough-brittle composite fracture. This method showed great potential in manufacturing aluminum-steel transition joints.