Product Name: Tantalum Carbide (TaC) 
Specification: 0.8-10um (D50) 
Appearance: Irregular 
Color: Black Grey 
Features: high melting point, high hardness, high elastic modulus, good chemical stability, and corrosion resistance 
Application: Hard alloy, cutting tools, military, electrode materials, metal matrix composites and 

Tantalum carbide 
CAS No.： 12070-06-3 
EINECS number: 235-118-3 
Molecular formula: CTa 
Molecular weight: 192.96 
Melting point: 3880 ℃ 
Boiling point: 5500 ℃ 
Hardness: 2100HV0.05 
Crystal form: Light brown metallic cubic crystalline powder, belonging to the sodium chloride type cubic crystal system. 
Density: 14.3g/cm3 
Resistance: 30 Ω at room temperature 
Properties: Insoluble in water, insoluble in inorganic acids, soluble in mixed acids of hydrofluoric acid and nitric acid, and decomposable. Strong antioxidant capacity, easily melted and decomposed by potassium pyrosulfate. 
Application: (1) Tantalum carbide has high hardness, melting point, and good high-temperature performance, mainly used as an additive for hard alloys. Adding tantalum carbide can refine the grain size of hard alloys, significantly improving their thermal hardness, resistance to thermal shock, and resistance to thermal oxidation. Long term dependence often involves adding a single tantalum carbide to tungsten carbide (or tungsten carbide and titanium carbide), mixing with binder metal cobalt, forming, and sintering to produce hard alloys. In order to reduce the cost of hard alloys, tantalum niobium composite carbides are often used. Currently, the main tantalum niobium composites used are: TaC: NbC with 80:20 and 60:40. The highest amount of niobium carbide in the composite reaches 40% (generally considered to be no more than 20%). In the production of hard alloys, TAC mainly plays a role in inhibiting the growth of alloy grains, improving the alloy's red hardness and wear resistance, enhancing the alloy's oxidation resistance and corrosion resistance, and improving the alloy's microstructure. In ordinary tungsten cobalt and tungsten cobalt titanium hard alloys, only 0.3% -0.4% needs to be added. TaC cannot be wetted by cobalt alone and needs to be combined with WC and TiC solid solutions. 
(2) Used as an additive for powder metallurgy, cutting tools, fine ceramics, chemical vapor deposition, hard and wear-resistant alloy cutting tools, tools, molds, and wear-resistant and corrosion-resistant structural components to improve the toughness of alloys. The sintered body of tantalum carbide displays a golden yellow color and can be used as a watch decoration. 
Preparation method: 
(1) Restoration method 
The main preparation process is to mix tantalum oxide or carbon powder with carbon, and perform primary and secondary carbonization under high temperature, hydrogen protection, or vacuum conditions to generate tantalum carbide. The reason for the need for secondary carbonization is that the first carbonization is not thorough due to various factors, and the chemical carbon, free carbon, and impurities in the product are difficult to meet the requirements. Excessive carbon and tantalum in secondary carbonization form carbides under vacuum conditions. The main factors affecting the quality of carbides include: carbon content, raw material particle size and purity, loading method, carbonization temperature, carbonization time, secondary carbonization, etc. The above method can only prepare block shaped or large particle shaped TaC. 
From an industrial perspective, the carbon thermal reduction method of metal oxides is the most widely used method, but its reduction temperature is above 1500 ℃, and the reaction rate is very slow. At higher temperatures, TaC particles tend to grow and reduce their mechanical properties. In industry, micrometer sized tantalum carbide powder is prepared using ball milling method. The method involves mixing solid carbon balls with tantalum pentoxide and ball milling them in a vacuum and argon atmosphere. At a high temperature of 1700 ℃, reduction and carburizing treatment are carried out to obtain tantalum carbide powder with a particle size greater than 2 μ m. In order to accelerate the reaction speed and improve the shortcomings of traditional methods, microwave reduction can effectively increase the powder diffusion rate, reduce the reaction temperature by 50-100 ℃, shorten the processing time, save energy, and save costs. The preparation process is as follows: Ta2O5+carbon black is reduced by microwave at 1250 ℃ -1500 ℃, with a heating rate greater than 100 ℃/min. When the temperature exceeds 1400 ℃, Ta2O5 is completely converted to TaC without generating any intermediate phase or Ta low valence oxide. 
(2) Legalization 
Chemical synthesis is a common solid-phase method for preparing TaC. Under certain conditions, T and C undergo a chemical reaction to directly generate TaC: Ta (s)+C (s) → TaC (s) 
(3) Chemical vapor deposition method 
The CVD method for preparing TaC coatings requires the use of the source material TaCl5. TaCl5 is vaporized at 500K, and the vaporized TaCl5 is used as a gas source and poured into a CVD furnace to deposit TaC together with other introduced reducing atmospheres. The reaction process is as follows: 
TaCl5+CmHn+H2→TaC+HCl+H2 
Storage conditions: Inert gas anti-static packaging should be sealed and stored in a dry and cool environment, and should not be exposed to air for a long time. 
Tantalum carbide (TaC) is a type of ultra-high temperature ceramic material, commonly referred to as ultra-high temperature ceramics (UHTCs), which have a melting point exceeding 3000 ℃ and are used in high temperature and corrosive environments above 2000 ℃ (such as oxygen atom environments), such as ZrC, HfC, TaCHfB2, ZrB2, HfN, etc. Tantalum carbide has a melting point of up to 3880 ℃, high hardness (Mohs hardness 9-10), large thermal conductivity (22W · m-1 · K-1), high bending strength (340-400MPa), and small thermal expansion coefficient (6.6 × 10-6K-1). It exhibits excellent thermochemical stability and superior physical properties, and has good chemical and mechanical compatibility with graphite and C/C composite materials. Therefore, TaC coatings are widely used in aerospace thermal protection, single crystal growth, energy electronics, and medical devices. 
Application areas: 
1) TaC has excellent thermochemical stability and physical properties, and has good chemical and mechanical compatibility with graphite. Preparation of TaC coating on graphite surface can effectively enhance its oxidation resistance, corrosion resistance, wear resistance, and mechanical properties. Especially suitable for growing GaN or AlN single crystals in MOCVD equipment and SiC single crystals in PVT equipment, the quality of the grown single crystals is significantly improved. Due to the excellent acid and alkali resistance of TaC coating to H2, HCl, NH3, in the silicon carbide semiconductor industry chain, TaC can also completely protect the graphite substrate material and purify the growth environment during epitaxial treatments such as MOCVD. 
2) Porous tantalum carbide ceramics can better achieve gas-phase component filtration, adjust local temperature gradients, guide material flow direction, and control leakage. 
3) With the development of modern aircraft such as aerospace vehicles, rockets, and missiles towards high speed, high thrust, and high altitude, the requirements for high temperature resistance and oxidation resistance of their surface materials under extreme conditions are also increasing. When aircraft enter the atmosphere, they face extreme environments such as high heat flux density, high stagnation pressure, and fast airflow erosion, as well as chemical erosion caused by reactions with oxygen, water vapor, and carbon dioxide. When an aircraft flies out and into the atmosphere, the air around its nose cone and wings is severely compressed, causing significant friction with the surface of the aircraft and resulting in its surface being heated by the airflow. In addition to aerodynamic heating during flight, the surface of the aircraft is also affected by solar radiation, environmental radiation, etc., causing the surface temperature of the aircraft to continuously rise. This change will seriously affect the service condition of the aircraft. TaC is a member of the ultra-high temperature resistant ceramic family. Its high melting point and excellent thermodynamic stability make it widely used in the hot end of aircraft, such as providing protection for the surface coating of rocket engine nozzles. 
4) TaC has broad application prospects in fields such as cutting tools, grinding materials, electronic materials, and catalysts. For example, adding TaC to hard alloys can prevent grain growth, increase the hardness of hard alloys, and improve their service life; TaC has good conductivity and can form non stoichiometric compounds. The conductivity varies with different components, which makes TaC have attractive application prospects in the field of electronic materials; In terms of catalytic dehydrogenation of TaC, studies on the catalytic performance of TiC and TaC have shown that TaC has little catalytic activity at lower temperatures, but its catalytic activity significantly increases above 1000 ℃. Research on the catalytic performance of CO has found that the catalytic products of TaC at 300 ℃ include methane, water, and a small amount of olefins.