The hydrogen absorption behavior of C15 Laves phase compounds ZrV₂ has been systematically investigated by the first-principles calculations. In the C15 Laves phase, hydrogen atoms can occupy three possible tetrahedral interstitial positions—2A2B, 1A3B, and 4B—in which the 2A2B site, being the largest interstitial space among the three possible positions, is the most favorable interstitial site. In addition, 2A2B and 1A3B sites can form some ordered clathrate-type structures to provide diffusion paths for hydrogen atoms to move inside the ZrV₂ compounds. According to the calculated barrier energies of H atoms in different diffusion paths in ZrV₂, it is found that hydrogen atoms prefer intra-ring diffusion to inter-ring diffusion, although inter-ring diffusion provides a non-negligible contribution to the overall H diffusion process. However, the existence of 1A3B sites can facilitate the diffusion of hydrogen atoms in adjacent six-membered rings. Finally, the absorption energies and electronic structures of ZrV₂H_x (x = 0.5, 1, 2, 3, 4, 6, 7, and 12) were computed, and the results show that the hydrogen content reaches its maximum on the condition of 6 < x < 7. Moreover, hydrogen atoms make a stronger covalent bond with V atoms than with Zr atoms.

Metal and alloy toughening was the core and long-term research direction in materials filed. As grain size had bimodal distribution, micro/nano-structured alloys presented excellent comprehensive mechanical properties, and this had become one of the research hotspots and developing trends in the field of nanotechnology. In-situ tensile test was a direct and effective method to study the deformation mechanism of materials, which revealed the multiple mechanisms responding to feature grain sizes and provided reliable experimental means and research technique. Research on development of in-situ technique and its applications in mechanical properties was reviewed in this paper according to the recent advances on the modern mechanical properties for high strength and high plasticity alloy at home and abroad. The disadvantages of the present study of preparation methods and investigation techniques for high-performance alloy had been concluded. Finally, the development prospects of high strength and high plasticity alloy materials were analyzed.