Design of TiCx nanoparticles and their morphology manipulating mechanisms by stoichiometric ratios: Experiment and first-principle calculation

Abstract The morphology of TiC x nanoparticles is one of the most significant inherent factors that influence their comprehensive performance and extensional applications. However, the design of TiC x nanoparticles and their growth morphologies manipulating in the Al melt are always in challenges, while the stoichiometric ratios controlled synthesis will show a promising prospect. In this study, TiC x ceramic nanoparticles with different stoichiometric ratios (x = 0.5, 0.625, 0.75, 0.875 and 1.0) were fabricated successfully by combustion synthesis in Al-Ti-C reaction system. Based on the evaluation of nanosized TiC x specific exposed planes in the Al melt, the stoichiometric ratios manipulated the Al/TiC x interface performances, including interfacial stability, the nature of bonding and the interface electron transfer were analyzed via first-principle calculation. With the increasing stoichiometric ratios, the TiC x (100) exposed planes in the Al melt gradually stabilized and became exposed, while the TiC x (111) planes show poor stability and gradually shrank and disappeared. The corresponding morphology will also evolve from octahedron to truncated-octahedron then spheroid with increasing x . Moreover, those interface performances can be selectively controlled by the stoichiometric ratio of TiC x nanoparticles. Finally, morphologies with specific exposed crystal planes in the Al melt can be effectively designed and manipulated for various applications.