Prediction of the interfacial relationship between Y₂O₃ and TiN using first-principles calculations

Area of Science:

• Materials Science
• Physical Chemistry
• Metallurgy

Background:

• Hypereutectic Fe-Cr-C-N-Ti alloys exhibit excellent wear resistance due to the TiN strengthening phase.
• Rare earth oxides, specifically Y2O3, are explored for their potential to refine TiN and improve alloy service life.

Purpose of the Study:

• To investigate the interfacial relationship between Y2O3 and TiN using first-principles calculations.
• To assess the effectiveness of Y2O3 as a hetero-nucleation core for TiN formation.
• To provide a theoretical basis for developing new Fe-Cr-C-N-Ti-Y2O3 alloys.

Main Methods:

• First-principles calculations were used to determine the mismatch degrees between low-index crystal planes of Y2O3 and TiN.
• An interfacial model (Y2O3//TiN) was established based on minimum mismatch and surface convergence tests.
• Interfacial properties, including adhesion work and interface energy, were calculated for various interfacial models.

Main Results:

• The Y2O3 (111) and TiN (110) planes exhibit an 8.19% mismatch, indicating moderate hetero-nucleation effectiveness.
• The most stable interface is the O-N terminated model, characterized by Ti-O ionic and N-O covalent bonds.
• Surface energy convergence was achieved at 2.75 J m^-2 for the TiN(110) surface model with 9 layers.

Conclusions:

• Y2O3 satisfies the conditions to act as a hetero-nucleation core for TiN.
• The formation of a stable O-N terminated hetero-nucleation interface is favored.
• This research provides theoretical support for the development of advanced Fe-Cr-C-N-Ti-Y2O3 alloys with enhanced properties.