Investigation of separation of A1050 aluminum and SS400 steel joined body by foaming

Porous aluminum is fabricated by heating and foaming a precursor, which is fabricated by adding a foaming agent and a thickening agent to solid aluminum. In recent years, joining technologies have been developed owing to multi-materialization, but from the viewpoint of recycling, it is necessary to separate the joined materials when they are to be disposed. It is well known that the strength of porous material decreases compared with that of the base material. Taking advantage of this fact, we attempted to reduce the strength of the joining area by adding a foaming agent to the joining area when joining dissimilar metals, and then heating and foaming the joining area at the time of disposal for the purpose of easy separation. As a result, it was found that the fracture load and absorbed energy required to fracture the specimen can be reduced just by heat treatment, but they can be further reduced by heating and foaming the joining area compared with those in the case of a nonporous specimen. © 2022 The Japan Institute of Light Metals.