Processing and Characterization of Hybrid Multi-material Joints

A new method for fabricating a carbon nanotube (CNT)-mixed joint is introduced by applying friction stir processing to Mg sheets coated with CNT powders. This technique transforms the processing area into a joining region containing CNTs through Mg/CNTs intermixing, as well as the progressive disintegration and separation of CNT entanglements caused by the shear flow of the metal. This process facilitates the uniform distribution of CNTs within the butt weld nugget zone (BW-NZ). The amalgamation of CNTs in the hybrid material joint positively affects dynamic recrystallization and inhibits grain growth within the BW-NZ, thereby causing a reduction in grain size. Additionally, CNTs weaken the basal texture, making the strength modification of carbon-based nanomaterials dominant when employing fine grain strengthening and intrinsic strengthening techniques. Incorporating CNTs enhances both strength and ductility by increasing the dislocation storage capacity. This study presents a novel solid-state joining approach that improves the joint strength of butt-welded sheets with mild ductility damage. Moreover, it offers a strategy for attaining a hybrid material joint in the field of metal plate butt welding.