Architectured ceramics with tunable toughness and stiffness

Abstract Architectured materials/structures provide avenues as a robust design strategy to enhance the strength and toughness of brittle materials. Architectured materials and interfaces can transform brittle ceramics into impact resistant structures with tunable toughness, strength and stiffness. In this work, we have developed a fast, simplified and industrially scalable fabrication technique based on laser machining for large-scale architectured ceramics. Utilizing this technique, a new class of advanced ceramics based on bio-inspired architectures have been designed to improve and tune the mechanical response in multi-impact conditions. The multilayered ceramics were manufactured by stacking laser-cut hexagonal tiles (with differing cut depths) and interlayers made of the commercial monomer Surlyn®. Stereo/3D laser scanning microscopes and nondestructive evaluation (NDE) techniques including infrared thermography, X-ray radiography and X-ray penetrant inspection were used to assess the architectures before and evaluate the multiscale damage after each impact. It was found that the multilayered architectured ceramic systems with a partial-cut depth (i.e., 40% and 70%) exhibited higher dynamic energy absorption performance (up to 220% for the 3rd impact) and higher stiffness (up to 80% for the 3rd impact) than the multilayered plain ceramic. The results showed a bell-shaped response in the partial-cut architectured ceramics, indicating tough materials (opposed to the plain one) and superior multi-hit resistance owing to the energy dissipation mechanisms including plastic deformation in adhesive interlayers and inter-cuts, crack deflection, frictional energy dissipation due to tile sliding (absent toughening mechanisms in the plain system) as well as ceramic fracture upon flexural cracks in the partial-cuts and delamination crack (absent mechanisms in the 100% cut-depth architectured system).