Solid oxide membrane-assisted controllable electrolytic fabrication of Ti5Si3/TiC composites in molten salt

Abstract

The titanium silicide Ti5Si3 possesses many desirable properties, such as a high melting point, excellent high-temperature oxidation resistance, low density, and relatively high hardness, and it is considered a promising structural intermetallic compound. However, like most ceramic materials, originating from low symmetry (D88) in its crystal structure, Ti5Si3 has poor fracture toughness and limited flexibility at room temperature, and at high temperatures, its creep resistance also drops sharply, which hinders its application. To overcome these shortcomings, it is suggested that TiC is a practical addition to Ti5Si3 to overcome the brittleness. Compared with monolithic Ti5Si3, Ti5Si3/TiC composites have a higher fracture toughness. Ti5Si3/TiC composites can be prepared by many ways, which commonly require high energy cost, complex processes and provide low efficiency. Therefore, the search for environmentally friendly strategies for the production of Ti5Si3/TiC is still ongoing. This article proves that we can successfully prepare Ti5Si3/TiC composites from CaTiO3/SiO2/C precursor by using SOM technology and explores the reaction mechanism of electrochemical process. In the process of electroreduction of CaTiO3/SiO2/C particles into Ti5Si3/TiC composites, we mainly used SOM technology at 1273 K and 4.0 V in molten CaCl2 and under an argon atmosphere. The results show that the Ti5Si3/TiC composites can also be successfully electrosynthesized from CaTiO3/SiO2/C precursors by using SOM-based anode systems at 1273 K and 4.0 V in molten CaCl2. The Ti5Si3/TiC composites can been successfully electrosynthesized from CaTiO3/SiO2/C precursors by using SOM-based anode systems at 1273 K and 4.0 V in molten CaCl2. This work demonstrates that Ti5Si3/TiC composites have been successfully electrosynthesized from CaTiO3/SiO2/C precursors using SOM-based anode systems at 1273 K and 4.0 V in molten CaCl2. The Ti5Si3/TiC has a smooth surface and micro/nano-porous structure. The formation routes for Ti5Si3 and TiC are independent. In summary, the SOM-assisted controllable electroreduction process has the potential to provide a novel one-step route from CaTiO3/SiO2/C precursors to Ti5Si3/TiC composites in molten salts. In summary, this paper demonstrates that Ti5Si3/TiC composites have been successfully electrosynthesized from CaTiO3/SiO2/C precursors by using SOM-based anode systems at 1273 K and 4.0 V in molten CaCl2.the main intermediate stages in the electrolysis process include Ti2O3, Ca2SiO4, and SiC. The above steps of CaTiO3, SiO2, C → Ti2O3, Ca2SiO4, SiC → Ti5Si3/TiC make up the electroreduction process.Compared with the initial powders before electrolysis, the obtained Ti5Si3/TiC composite has a smooth surface and possesses a nodular microstructure.