Corrosion and structural properties of lightweight magnesium and aluminum alloy cores based sandwich composites

Metal plate core-based sandwich composites have the potential to revolutionize various industrial fields due to their mechanical strength and vibration damping. In this study, AZ91 (a magnesium alloy) and Al1050 (an aluminum alloy) metal core-based sandwich composites of AZ91/carbon fiber-epoxy, AZ91/glass fiber-epoxy, Al1050/carbon fiber-epoxy, and Al1050/glass fiber-epoxy sandwich composites were manufactured. These composites' mechanical and dynamic properties were determined through tensile, three-point bending, and vibration tests. AZ91-reinforced carbon fiber composites exhibited a 28.8% higher tensile strength than glass fiber composites, while Al1050-reinforced carbon fiber composites showed a 17.2% higher tensile strength performance than glass fiber composites. Moreover, AZ91 reinforcement led to composites with higher average flexural strength for both fibers. In vibration tests conducted under clamped and free-free boundary conditions, the highest first natural frequency was observed in AZ91/carbon fiber samples, sparking further interest. Conversely, the highest first damping ratio was observed in Al1050/glass fiber specimens. In addition, the corrosion behavior of sandwiches was evaluated, and it was found that glass fiber provided better corrosion resistance than carbon fiber. Highlights: Sandwich composites comprising AZ91/Al1050 cores and carbon/glass fiber reinforced epoxy face sheets were manufactured. Galvanic corrosion effects were evaluated, and glass fiber was found to provide higher corrosion resistance. AZ91/carbon fiber sandwich showed 28.8% higher tensile strength than glass fiber. Vibration tests revealed the AZ91/carbon fiber sandwich had the highest first natural frequency. Al1050/glass fiber sandwich exhibited the highest first damping ratio.