Mechanical Behavior of Layered Composite Structures of Aluminum Foam Partially Filled with Polyamide

In this study, the mechanical properties of layered composite structures were investigated. We achieved the layered structure by hot-pressing 1 mm, 3 mm, or 5 mm thick polyamide 6 (PA) sheets into the pores on the top and bottom sides of an open-cell metal foam at 240 °C and 15 MPa (150 bar). The PA-infiltrated depths varied with the thickness of the hot-pressed PA sheets. According to the bending and post-impact bending tests, flexural strengths improved as the infiltration depth of PA increased. Compared to the metal foam, a maximum of 15% increase in flexural strength and a 400% increase in residual flexural strength were measured. However, using a 1 mm thick PA sheet lowered the flexural strength of the open-cell metal foam. We found that the 1 mm thick PA sheet failed to fully infiltrate the foam pores, resulting in residual voids at the metal-PA interface, which caused premature fracture during bending.