Research development in preparation of TiC materials via molten salt-assisted method

Titanium carbide is a typical transition metal carbide that has been widely used in the machinery manufacturing, chemical, electronic, and metallurgical industries because of its many unique properties such as high hardness, high melting point, good wear resistance, and good electrical conductivity. With continuous expansion in the applications of titanium carbide materials, the market has developed new requirements on the purity, particle size, particle size distribution, and microstructure of titanium carbide materials. Addition of titanium carbide to the surface of some materials or plated substrates to alter the internal or surface microstructure of the materials and improve the physical or chemical properties of the materials can provide new application prospects in metal matrix composites, ceramic composites, and coating materials. Titanium carbide materials possessing better dispersion, uniform particle size, good crystallization, and good stoichiometry are desired in biosensors, hard coatings, composite electrodes, electrocatalytic active materials, foam stabilizers, and other applications. Titanium carbide is synthesized through various methods such as carbothermal reduction, mechanical alloying, self-propagation high-temperature synthesis, and molten salt-assisted synthesis. Often, synthesis methods of titanium carbide require high reaction temperatures and result in the poor dispersion of powder particles. Therefore, an energy-saving method having high efficiency and in which the purity and morphology of the powder particles can be controlled needs to be developed. This method can be used to develop various kinds of powder materials. Among various preparation methods, molten salt-assisted synthesis (MSS) has gained an increasing amount of attention due to its low preparation temperature, short reacting time, and high efficiency. In recent years, tremendous progress has been made in the development of the MSS method. The MSS method can be used to prepare titanium carbide powders, titanium carbide coatings, and titanium carbide fibers with varying particle sizes, morphologies, and purities. This review offered a retrospection on the research studies conducted on the preparation of titanium carbide materials via molten salt-assisted methods in China and worldwide, and this review provided elaborate descriptions about the advantages and disadvantages of various preparation methods such as carbon/metal thermal reduction, electrochemistry, direct carbonation, and microwave heating. This review mainly focused on the preparation process, preparation principle, purity of products, and morphology. In this review, key issues such as eliminating impurities, increasing purity of titanium carbide, and controlling the morphology of titanium carbide were discussed, and relevant researches topics that can be done in the future were proposed. This review helps provide a reference for the low-cost and high efficiency production of high-quality titanium carbide materials.