First-Principles Calculation of Elastic and Structural Properties of Be-W Intermetallic Compounds

Beryllium-tungsten (Be-W) intermetallic compounds are promising candidates for fusion-reactor plasma-facing components and aerospace high-temperature structural materials owing to their low density, high elastic modulus, high melting point and excellent irradiation-corrosion resistance. Nevertheless, experimental acquisition of intrinsic physical properties for single-phase Be-W intermetallics remains challenging because of significant differences in the melting points of constituent elements and the tendency for elemental segregation during preparation. In this paper, first-principles calculations based on density functional theory with the GGA-PBE functional were performed to investigate the crystal structure, thermodynamic stability, electronic bonding and mechanical properties of Be2W, Be12W, and Be22W. The results reveal that Be12W has the lowest formation enthalpy and exhibits the strongest phase-forming ability, while Be2W shows relatively poor thermodynamic stability. All three phases are metallic with no band gap, and their bonding exhibits strong Be-p–W-d orbital hybridization with partial covalent features on the basis of metallic bonding. According to the Born–Huang stability criteria, Be2W, Be12W and Be22W are all mechanically stable. Be2W possesses superior resistance to volumetric deformation; Be12W achieves the highest shear modulus, Young’s modulus and theoretical Vickers hardness, but displays relatively high brittleness; Be22W has low elastic modulus and hardness within the range of 2–8 GPa, indicating favourable machinability yet insufficient structural stability. Comprehensive analysis demonstrates that Be12W is the optimal target phase for high-temperature irradiation-resistant Be-W-based structural materials. This work clarifies the structure–property relationships of Be-W intermetallics and provides theoretical support for composition optimization, phase regulation and experimental development of relevant advanced materials.