Development of a Lightweight Multi-Material Joining Concept through Solid State Welded Al-Steel Bimetal Adaptor 2023-01-0940

In present work prefabricated multi-material adaptors welded with solid state welding such as roll bonding were explored. Aluminium-Steel adaptor manufactured by roll bonding was used which also has a highly oxidation resistant interface layer which resist the formation of intermetallic. The bimetal adaptors were manufactured by a machining process which carve out the adaptors in required design and configurations from a flat multi-material plate. The bimetal adaptors were used to join aluminium extrusion to steel by arc welding. The Steel side of multi-material adaptor is arc welded with steel and Aluminium side is arc welded with aluminium extrusion tube. This resulted into fabrication of a lightweight multi material joint with aluminium tube and steel. Secondary arc welding process was optimized to keep the interface of primary solid state welded adaptor below 350 Deg C. Detailed weld interface analysis was carried out to understand the effect of secondary arc weld on the interface of solid-state primary weld. Optical microscopy, SEM and SEM-EDX were utilized for microscopic and elemental analysis. Harmful Intermetallic Compounds was not observed at interface of bimetal adaptor. Corrosion performance of joint was also evaluated as per ASTM B117 till 500 hours under 5% NaCl salt. Developed process concept was also evaluated for durability performance which sustained 150000 cycles without failure. It also sustained torque upto 4000nm. Thus, developed concept can be used to manufacture lightweight Aluminium-Steel components without the need of sophisticated techniques through conventional arc welding.