Resistance is not futile: The use of projections for resistance joining of metal additively and conventionally manufactured parts

Metal additive manufacturing processes can produce geometrically complex and lightweight components. While conventionally manufactured components are frequently assembled to form larger parts, additive manufacturing can be used to print an entire part without needing any assembly. However, additive manufacturing processes are frequently limited in the size of the part they can produce, and it is often more economically favourable to conventionally manufacture larger or simpler geometries, such as large sheets. In this study, we demonstrate the use of a resistance joining process to facilitate the assembly of additive manufactured components. Projections are designed into additive manufactured parts to allow for joining with a conventional metal sheet. Joint performance is evaluated as a function of design choices, including the type of infill, part thickness, and proximity to adjacent joints, as well as the resistance joining process parameters. High strength joints capable of withstanding an applied torque of up to 80 Nm were obtained and functional parts were assembled to a conventionally manufactured sheet as a demonstration of the process. Incorporating projections for resistance joining into the design stage of additive manufactured parts has the potential to facilitate the use of additive manufactured components in larger assemblies and broaden the adoption of additive manufacturing in industry.