The influence of W-doping concentration on the structural stability, elastic properties, hardness, and brittle-to-ductile behavior of ZrB2 high-temperature ceramics

Abstract

To improve the mechanical properties of ZrB₂ ceramics, the influence of W-doping on the structural stability, elastic properties, hardness and brittle-to-ductile behavior of ZrB₂ is studied using first-principles calculations. Three W-doping concentrations are considered. The results show that although W-doped ZrB₂ exhibits both thermodynamic and dynamical stability, the structural stability of W-doped ZrB₂ weakens with increasing W-doping concentration, particularly showing a reduction in dynamical stability. Furthermore, W-doping enhances the volume deformation resistance of ZrB₂, while it reduces the shear deformation resistance and Vickers hardness of ZrB₂. In particular, W-doping induces a trend of brittle-to-ductile transition in ZrB₂ ceramics. Essentially, this improvement of the trend of brittle-to-ductile transition arises from the introduction of W-doping, which weakens the electronic interaction between B and B atoms along the shear direction. Therefore, we believe that the W metal is a promising element for improving the mechanical properties of ZrB₂ high-temperature ceramics.