Vacancy induced brittle-to-ductile transition of Nb5Si3 alloy from first-principles

Enhancing the Vickers hardness, melting point and thermodynamic properties of hafnium dodecaboride

“…The Debye temperature of TM-doped HfB 12 is calculated by the average sound velocity, which is obtained by: 53,54…”

Influence of vacancy on structural and elastic properties of NbSi 2 from first-principles calculations

“…Early works have focused on the mechanical properties of Nb\ \Si based superalloys [7][8][9][10][11][12][13]. For example, the calculated bulk modulus and shear modulus of Nb 5 Si 3 are 193 GPa and 125 GPa [14], and the bulk modulus and shear modulus of Nb 3 Si are 183 GPa and 72 GPa [15], respectively. Recently, our works further found that the Young's modulus and Vickers hardness of NbSi 2 are 339 GPa and 27.5 GPa [16], which are larger than that of Nb 5 Si 3 and Nb 3 Si.…”

Prediction of New Structure, Phase Transition, Mechanical, and Thermodynamic Properties of Nb3Si

“…It is worth noticing that the calculated bulk modulus of Nb 3 Si with Ta 3 Si‐type structure is about 182 GPa, which is larger than that of other structures. For Ta 3 Si‐type with tetragonal structure, although the shear modulus is much smaller than that of Nb 5 Si 3 (125 GPa by GGA), the bulk modulus of the former is slightly smaller than the latter by 11 GPa. Therefore, Nb 3 Si with Ta 3 Si‐type structure can guarantee the mechanical properties of Nb/Nb 5 Si 3 composites.…”

“…The earlier works have proposed that the brittle fracture of Nb‐based silicides is attributed to the brittle phases such as Nb 5 Si 3 and Nb 3 Si . Although the intrinsic brittleness of Nb 5 Si 3 is affirmed experimentally and theoretically, the nature of brittle, or ductile behavior of Nb 3 Si is unknown.…”