Unique mechanical properties of nano-grained YAG transparent ceramics compared with coarse-grained partners

In order to improve the inherent brittleness of the conventional coarse-grained YAG transparent ceramics, nano-grained YAG transparent ceramics were fabricated at 5GPa/450°C using the super high pressure sintering technique. Their mechanical properties were investigated by nanoindentation and the Vickers indentation measuring methods. It was found that the nano-grained YAG transparent ceramics exhibited much better ductility compared with the coarse-grained counterparts. The grain-boundary sliding provides the main contribution to plastic deformations of nano-grained YAG transparent ceramics. [Display omitted] •The nano-grained Y3Al5O12 transparent ceramics were prepared by using high pressure technique.•Nano-grained Y3Al5O12 transparent ceramics were studied by nanoindentation.•Nano-grained Y3Al5O12 transparent ceramics have a greater fracture toughness than the coarse-grained partners.•Grain-boundary sliding provides the main contribution to plastic deformation of nano-grained Y3Al5O12 transparent ceramics.