Extreme Energy Dissipation via Material Evolution in Carbon Nanotube Mats

Thin layered mats comprised of an interconnected meandering network of multiwall carbon nanotubes (MWCNT) are subjected to a hypersonic micro‐projectile impact test. The mat morphology is highly compliant and while this leads to rather modest quasi‐static mechanical properties, at the extreme strain rates and large strains resulting from ballistic impact, the MWCNT structure has the ability to reconfigure resulting in extraordinary kinetic energy (KE) absorption. The KE of the projectile is dissipated via frictional interactions, adiabatic heating, tube stretching, and ultimately fracture of taut tubes and the newly formed fibrils. The energy absorbed per unit mass of the film can range from 7–12 MJ kg−1, much greater than any other material. Porous, unoriented multiwall carbon nanotube mats dissipate extraordinary amounts of kinetic energy by a variety of processes via their ability to dramatically reconfigure, align, and strengthen during shock impact to exhibit the highest specific energy absorption (≈12 MJ kg−1) for projectile perforation of any known material.