“…Nevertheless, the anisotropic properties (predominant [001] texture [14,22]) of hexagonal diborides, combined with the shear modulus differences, need to be considered to interpret the hardness evolution in the case of the TiB 2 /WB 2 system. Additionally, for the TiB 2 /ZrB 2 system, the influence of a possible tissue phase at the absolute values of the fracture toughness-not their progression as the elemental composition is similar throughout the coating series [23].…”