Effect of explosive welding parameters on Al/LCS interface cladded by low velocity of detonation explosive welding (LVEW) process

Interfacial properties govern the metallurgical and mechanical behaviour of welded specimens. Hence to study the effect of different parameters on weld interface is an important aspect to bring the desired output properties for various applications. In this study, a newly developed low velocity of detonation explosive welding (LVEW) process was applied to clad aluminium (Al) and low carbon steel (LCS) plates. Loading ratio (R) and stand-off distance (SD) were adopted for this study, as these two mostly affect the welding behaviour and act as important welding parameters. Microstructural examination as well as mechanical tests were performed. Three kinds of morphology were observed at the weld interface, i.e. large waves (LW), small irregular waves (SIW) and smooth flat interface (SFI), where SIW and SFI contribute interface devoid of voids, intermetallic and melting pockets. But at higher R and SD, AlFe and Al 2 Fe intermetallic were observed in non-continuous form in micron range. Elemental analysis confirmed the local diffusion with very thin diffusion thickness of 0.8–2 μm. Micro-hardness profile discloses the shock hardening effects across the vicinity of the weld interface, where an increase in hardness value was above the parent value. Chisel test and shear strength test also confirmed the good quality of bonding, while in shear fracture study, dimple structure was dominated in all the specimens. All these observations concluded that for cladding Al/LCS, LVEW process is best suitable and further, the practicability of these welded plates was checked by fabricating components like bi-metallic O-ring (push-fit type), hollow cylinder and bolts.