Pop-in phenomenon at nanoindentation and fracture toughness of two-phase ceramic composites

Material’s resistance to crack propagation corresponds to its fracture toughness. This characteristic can be calculated in laboratory tests, e.g. 3-point bending of notched bars or by indentation test. Spherical, conical, or pyramidal tips can be used during nanoindentation and micro indentation tests, e.g. Vickers, Berkovich, or Cube-Corner tip.