The stability, fracture toughness and electronic structure at γ-Ni (101)/(Ti, Nb)C (110) interface: A first-principles investigation

(Ti, Nb)C particles reinforced Ni45 coatings were made by a fiber laser system. The atomic structure, interfacial stability, interfacial fracture toughness, electronic structure and bonding nature of γ-Ni/(Ti, Nb)C were systematically analyzed using first principles calculations. TEM results showed that the interface orientation relationship of γ-Ni/(Ti, Nb)C was [01¯0](202)//[001¯](220). For the γ-Ni/(Ti, Nb)C interfaces, the stacking sites have much influence than the substitution position of Ti, the center-site stacking interfaces shower higher adhesion work and lower interface energy, indicating the interfacial alloying or new phases were prone to formed. According to the interfacial fracture toughness results, the mechanical failure of γ-Ni/(Ti, Nb)C may initiate at the interface or close to γ-Ni rather than (Ti, Nb)C. The bonding behavior of γ-Ni/(Ti, Nb)C was a blend of covalent bond and partial ionic bond. The chemical bonding properties of interfacial atoms were also discussed in view of electronic structure and partial density of states (PDOS) results.