Non-cuttable material created through local resonance and strain rate effects

Abstract

We have created a new architected material, which is both highly deformable and ultra‐resistant to dynamic point loads. The bio-inspired metallic cellular structure (with an internal grid of large ceramic segments) is non-cuttable by an angle grinder and a power drill, and it has only 15% steel density. Our architecture derives its extreme hardness from the local resonance between the embedded ceramics in a flexible cellular matrix and the attacking tool, which produces high-frequency vibrations at the interface. The incomplete consolidation of the ceramic grains during the manufacturing also promoted fragmentation of the ceramic spheres into micron-size particulate matter, which provided an abrasive interface with increasing resistance at higher loading rates. The contrast between the ceramic segments and cellular material was also effective against a waterjet cutter because the convex geometry of the ceramic spheres widened the waterjet and reduced its velocity by two orders of magnitude. Shifting the design paradigm from static resistance to dynamic interactions between the material phases and the applied load could inspire novel, metamorphic materials with pre-programmed mechanisms across different length scales.

Investigations of strain rate, size, and crack length effects on the mechanical response of polycaprolactone electrospun membranes

“…[54][55][56] It is well known that the mechanical response of polymers as other materials groups, metals, and composites, depends on the strain rate either positively or negatively. [57][58][59] Positive strain rate sensitivity is attributed to the fact that when the material is deformed at a faster rate, the plastic deformation mechanisms and their interactions with each other are enhanced and increase the stress level. 60,61 Therefore, understanding the fundamental deformation mechanisms of the PCL membranes by observing the microstructure at different strain rates is of utmost importance to discuss the observed strain rate sensitivity (Figure 2).…”

Methods Used for the Compaction and Molding of Ceramic Matrix Composites Reinforced with Carbon Nanotubes

“…The methods described above are powerful for molding ceramics from prospective inorganic materials that would come in broad use in the near future [213][214][215][216][217][218]. An innovative composite material has been reported very recently, which demonstrated an extremely high resistance against abrasive wear under the action of cutting tools and water jets [219]. The material consisted of a porous aluminum foam matrix and rows of alumina spheres contacting with each other through the matrix.…”