EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Layered ceramics are present in many applications and environments such as geology, energy storage or nuclear energy. Their layered structure results in a material with stronger in-(basal)-plane than out-of-plane ({0001} basal plane) bonds. This results in a strong surface energy anisotropy which is employed for instance to promote toughening in structural components but also as a way of inserting/extracting ions into a material in energy storage applications. In structural applications, MAX phases are used as high temperature ceramics, avoiding monolithic ceramic failure and allowing the material to achieve higher levels of fracture toughness required in structural applications. Furthermore, layered ceramics such as graphite are also used in Li-ion batteries as a way of storing Li ions. In both applications, the basal plane fracture and surface energy is a key factor. Hence, in this work we use small-scale fracture testing to evaluate the basal plane failure in two different layered materials: a Ti3SiC2 MAX phase and a Highly Ordered Pyrolytic Graphite (HOPG). This allows us to the measure the basal plane delamination energy and have access to a nanoscale characterisation of the fracture mechanisms. We use this setup to better understand their performance at a macroscale including their degradation mechanisms in their respective applications and optimise future material’s designs.