Study of dissimilar metal joint for low carbon steel and aluminum alloy with laser-Assisted Metal and plastic direct joining

Abstract

Dissimilar material joining is a key process in manufacturing multimaterial products. The objectives of this research is to produce and evaluate dissimilar metal joints of SPCD low carbon steel and A5052 aluminium alloy with sandwiching polyethylene terephthalate (PET) plastic for both joint strength and galvanic corrosion. Laser-Assisted Metal and Plastic (LAMP) joining method could produce the sandwich structure, owing to availability of either metal-side or plastic-side laser irradiation. The maximum tensile shear load achieved 5500 N in the obtained dissimilar metal joints of 30 mm width, where both the metal sheets were elongated. Typical Transmission Electron Microscope (TEM) pictures of the jointed areas demonstrate that the steel or the aluminum was tightly bonded to PET through each metal-oxide film in nanoscale size. Moreover, it was reveled that aluminum galvanic corrosion of the obtained joints was drastically suppressed in an immersion test using salt agar, compared with conventional laser welds of carbon steel and aluminum alloy.