Local fracture toughness measurements in polycrystalline cubic zirconia using micro-cantilever bending tests

•The micro-cantilever method is used and studied for fracture toughness measurements with notched specimen prepared by focused ion beam into a polycrystalline cubic zirconia.•Results obtained are coherent with literature toughness acquired by macroscopic tests.•Specimens are prepared to test specific crystallographic planes, and no significant difference is noticed between the three tested families {100}, {110} and {111}.•The method shows its attractiveness as local mechanical test for cracked materials as irradiated nuclear fuel. Local fracture toughness of a polycristalline ceramic was characterized with the micro-cantilever bending method. Beams were milled in single grains of cubic zirconia using a Focused Ion Beam (FIB) microscope. Grains with specific crystallographic orientations were chosen using Electron Backscatter Diffraction (EBSD) measurements to test specific plane families. Notched micro-cantilever beams were loaded up to fracture using a nano-indenter. For fracture toughness evaluation, three different methods were considered: an analytical solution, an isotropic Finite Element Method (FEM) calculation, and an anisotropic FEM model. These three methods gave similar toughness values. A good agreement was found with literature data measured on cubic zirconia single crystals at a macroscopic scale. In this work, no significant difference was noticed for fracture toughness between {100}, {110} and {111} crystallographic plane families. Such method could be used to characterize the local fracture properties of a sample showing extensive cracking such as irradiated nuclear fuel.