Interface-Driven Plasticity in Metal–Ceramic Nanolayered Composites: Direct Validation of Multiscale Deformation Modeling via In Situ Indentation in TEM

We present in situ indentation in a transmission electron microscope on Al-TiN multilayers with individual layer thicknesses of 50 nm and 2.7 nm to explore the effect of length scales on the plastic co-deformability of a metal and a ceramic. At 50 nm, plasticity was confined to the Al layers with brittle fracture in the TiN layers. At 5 nm and below, cracking in TiN was suppressed with co-deformation evident in both layers. The in situ transmission electron microscopy (TEM) straining results demonstrate a profound size effect in enhancing plastic co-deformability in nanoscale metal-ceramic multilayers, as well as direct validation of ex situ and 3-D elastic–plastic deformation models.