Hydrogen Transportation Behaviour of V-Ni Solid Solution: A First-Principles Investigation

Area of Science:

• Materials Science
• Physical Chemistry
• Computational Materials Science

Background:

• Hydrogen embrittlement degrades materials in metal-hydrogen systems.
• Alloying is a key strategy to mitigate hydrogen embrittlement.
• Vanadium (V) based alloys are relevant in metal-hydrogen applications.

Purpose of the Study:

• To investigate the impact of nickel (Ni) addition on the stability, dissolution, trapping, and diffusion of hydrogen (H) in pure vanadium (V).
• To evaluate the potential of V-Ni alloys for improved resistance to hydrogen embrittlement.

Main Methods:

• First-principles calculations were employed.
• Lattice dynamics and solution energy analyses were performed.
• Calculations focused on interstitial and vacancy hydrogen behavior in V-Ni systems.

Main Results:

• V-Ni solid solutions exhibit dynamic and thermodynamic stability.
• Ni addition reduces the stability of VHx phases, enhancing resistance to hydrogen embrittlement.
• Hydrogen atoms preferentially occupy tetrahedral and octahedral interstitial sites and diffuse rapidly along these paths.
• Ni addition minimizes hydrogen trapping by vacancies and suppresses hydrogen retention.
• Monovacancy defects significantly impede hydrogen diffusion, while Ni doping has a negligible effect on the overall hydrogen diffusion coefficient.

Conclusions:

• Nickel alloying effectively enhances the hydrogen embrittlement resistance of vanadium.
• The study provides fundamental insights into hydrogen-metal interactions in V-Ni alloys.
• Understanding these mechanisms is crucial for designing advanced metal-hydrogen materials.