Abstract
Multi-material joints consisting of aluminium joined with a higher strength metal such as steel, titanium or copper enable the production of hybrid products utilizing the strength of both metals, at the same time achieving a lower weight and design flexibility. However, upon recycling, the separation of the two metals into the original base metal constituents is a major challenge since cross-contamination between different metals can degrade the recycling possibilities. This chapter discusses possible solutions and methods for the automated disjoining of multi-material joints by the application of fracture strain, utilizing the differences in mechanical properties between the base materials and the nature of the intermetallic phases to separate the materials. The chapter exemplifies the method for steel–Al and Cu–Al welds, including results from laboratory experiments showing how this method can ensure a separation with minimum iron contamination, and suggest how the disjoining using fracture strain can be automated.