Protective potential of a metallic foam ceramic composite

Protective performance and a low weight of armors are one of the most important objectives in armor design. Because metallic foams may provide high protection without an extensive mass, they are used as a part of various laminated armor systems, [1]. Embedding ceramic spheres in metallic foam combines a high stiffness of ceramics with the flexibility of the lightweight cellular matrix. Interestingly, the material has also an extreme cutting resistance against mechanical tools such as angle grinder, drill bits or water jet cutter, [2]. Aluminium foam (EN AW-6060) matrix was embodied with the internal layout of stacked ceramic spheres (13 mm diameter) to manufacture panels for our testing campaing. The cellular core of the panel was bonded to 2 mm steel alloy faceplates. The total thickness of such a panel was 40 mm, while the thickness of the aluminum foam core was 36 mm. The objective of the experimental investigation was to assess blast wave propagation of the metallic foam ceramic composite (MFCC) panels in comparison to the blast mitigation performance of various sandwich panels with metallic foams as the interlayer. ISL internal detonation bunker was modified to evaluate the effects of blast on solid reference plates and on the developed metallic foam ceramic composite (MFCC) panels. Based on the principle of the explosively driven shock tube, the experimental tool provided a planar blast wave on 100 x 100 mm test samples. In this experimental configuration, the spherical blast wave generated a high-intensity and short-duration load. Explosive charges were detonated outside the bunker at a distance from 1 to 3 m, facing one of the three windows with an instrumented plate samples (with four load sensors) providing the real-time evolution of the force on the plate. Two high-speed cameras recorded the internal deformation of the plates/panels using Digital Image Correlation (DIC) to assess the efficiency of the blast mitigation. Our work evaluated the performance of a baseline panel with isotropic foam core and compared it to the novel MFCC configuration with ceramic sphere inclusions. After the experimental testing, further development of computational tools is needed to explore the potential of the technology via changes in the layout, spacing, foam porosity, thickness of the face sheets and other parameters.