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Ti-6Al-4V (TC4) has been widely used in dentistry as an implant biomaterial but is faced with difficulties in forming parts by traditional processing methods. Directed energy deposition (DED), a promising additive manufacturing technology, is very suitable for developing TC4/ZrO2 composite with different proportions of nano-ceramic additions (0, 5 or 10 wt%). As the content of alloying element Zr increased, the grains were refined, and the lattice distortion was more severe due to solid solution, both of which caused Vickers hardness of the composite to increase from 308 to 485. The electrochemical tests and corrosion morphology analysis indicated that the corrosion was intensified with the decrease of pH and the increase of F− ion concentration. The corrosion product detection showed that ZrO2 oxide might reduce the compactness of the TC4 passive film containing TiO2 and Al2O3, which resulted in a slight decrease in corrosion resistance but still satisfied the clinical requirements. Cytotoxicity and cytoskeleton staining results demonstrated that the composite was beneficial to biological safety and biocompatibility.

In this work, the mechanism for hydrogen generation of a recently reported Mo-oxo catalyst is investigated by theoretical method. A novel dimerization assembly mechanism has been elaborated. Structural details of the Mo-oxo complex which are essential to the catalytic activity are provided. The dimerization mechanism of hydrogen production is demonstrated to be more feasible than the monomer mechanism proposed in the previous work. Furthermore, proton-coupled electron transfer (PCET) reaction in the hydrogen bond network after dimerization assembly plays a very significant role on the hydrogen evolution from water by molybdenum-oxo catalyst. This study can be useful in understanding of many catalytic processes for hydrogen generation and designing new catalysis with high efficiency.

We have studied the effect of substitution of Gd for Nd on the exchange coupling in nanocomposite Nd2Fe14B–α-Fe magnets, and compared it with the substitution of Y and Sm for Nd. An enhancement of the exchange coupling is observed, due to the increased exchange correlation length originating from the decrease of the magnetocrystalline anisotropy of the hard-magnetic phase. The soft grains are pinned to the hard magnet grains at the interfaces by the exchange interaction, and more soft-magnetic grains participate in the exchange coupling.