In pursuit of damage tolerance in engineering and biological materials

The ability to image and quantify material behavior in real time at nano to near-macro length scales, preferably in three dimensions, is a crucial feature of modern materials science. Here, we examine such an approach to characterize the mechanical properties of three diverse classes of materials: (1) biological materials, principally bone, using both in situ small-/wide-angle X-ray scattering/diffraction to probe nanoscale deformation behavior and X-ray computed microtomography to study microscale damage mechanisms; (2) biomimetic materials, specifically a nacre-like ceramic, where microtomography is used to identify toughening mechanisms; (3) synthetic materials, specifically ceramic textile composites, using in situ microtomography to quantify the salient mechanical damage at ultrahigh temperatures. The mechanistic insights for the understanding of damage evolution and fracture afforded by these techniques are undeniable; as such, they can help provide a basis for the achievement of enhanced damage tolerance in structural materials.