▎ 摘　　要

Resistance spot welding of similar AISI-1008 steel plates and dissimilar AISI-1008/Al-1100 alloy joints were carried out using a graphene nanoplatelets interlayer and the underlying strengthening mechanisms were discussed. Weld strength of the joints depends on the welding current/time used for the resistance spot welding. An enhancement of similar to 49% and similar to 124% was reported at certain parameters for the similar and dissimilar joints, respectively. Optical microscopy, SEM, XRD, TEM and Raman spectroscopy was used for microstructural characterization. Microhardness studies at the weld nugget cross-section revealed an enhanced hardness at the fused zone for both the cases. Al-Fe rich intermetallics formation was reported at the interfacial zone of the dissimilar joints which played a role in hardness increment. Variation of nugget size with the increase in welding current was studied. Fractured surfaces were analyzed and it was concluded that shear dimple and a mix of the shear dimple and brittle fractures were dominant in cases of similar and dissimilar metal joints, respectively.