Why the melting point of tantalum carbide is very high?
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Author : Ada
Update time : 2023-02-13 13:11:32
What is tantalum carbide? Tantalum carbideis a black or dark brown metallic powder, cubic crystal system, hard, with a relative density of 13.9, a melting point of 3880 ℃, and a boiling point of 5500 ℃. It contains a mixture of 75% tantalum carbide and 25% hafnium carbide, with a melting point of more than 4200 ℃. Its chemical properties are extremely stable. It is insoluble in water, slightly soluble in sulfuric acid and hydrofluoric acid and soluble in the mixed solution of hydrofluoric acid and nitric acid. Tantalum pentachloride and methane are used as the reaction gas, argon is used as the carrier, and silicon carbide resistance is used to radiate and heat from the outside; Tantalum carbide or tantalum pentoxide is mixed with carbon black, formed by pressure powder, and heated in hydrogen or vacuum. It is used to manufacture cutting tools. Tantalum carbide (TaC) is a member of the ultra-high temperature ceramic family, with a high melting point (3880 ℃), high hardness (20 GPa), high elastic modulus (450 GPa), good electrical conductivity and thermal conductivity (25 ℃, 42.1 μ Ω · cm-1,22W · m-1 · K-1). It has excellent physical and chemical properties, such as chemical corrosion resistance, high-temperature strength, good thermal shock resistance, etc. The densification and molding method of TaC is mainly powder sintering, and the powder's quality directly determines the material's performance.
Preparation of tantalum carbide From the industrial point of view, the carbothermal reduction of metal oxides is the most widely used method. Still, its reduction temperature is above 1500 ℃, and the reaction rate is very slow. When the reaction temperature increases, the TaC particles easily grow and reduce their mechanical properties. In industry, the ball milling method is used to prepare micron-sized tantalum carbide powder. The method is to mix solid carbon balls and tantalum pentoxide and then put them into a vacuum and argon atmosphere for ball milling. At 1700 ℃, After reduction and carburization, the particle size can be greater than 2 μ M of tantalum carbide powder.
Use of tantalum carbide Researchers have conducted a lot of research on the strengthening effect of TaC on WC-Co cemented carbide γ Solid solubility of W in the phase [ii]; One believed that TaC can expand the width of the two-phase zone of WC-Co alloy, thus adjusting the carbon content of the alloy; Research shows that γ The solid solution in the phase decreases the solid solubility of W, while C γ The solid solubility in the phase is correspondingly increased. Therefore, TaC can slightly increase the carbon content of WC-Co alloy. Meanwhile, TaC can delay the γ The dissolution and precipitation process in the phase can prevent the WC grain from generally growing/in practical application γ The solid solubility in the phase is limited (w=0.3%), and the amount of TaC usually added to the alloy has far exceeded the saturated solid solubility value. TaC must be precipitated mainly in TaC-WC solid solution and exist in a free state. Still, its grain size is (1 μ m～2 μ m) Greater than WC grain size (<1 μ m). Therefore, free TaC-WC solid solution grains cannot be completely distributed in WC- γ On the phase boundary.
Price of tantalum carbide Tantalum carbide particle size and purity will affect the product's Price, and the purchase volume can also affect the cost of tantalum carbide. A large amount of large amount will be lower. The Price of tantalum carbide can be found on our company's official website.
Tantalum carbide supplier Luoyang Tongrun Nano Technology Co. Ltd. (TRUNNANO) Luoyang City, Henan Province, China, is a reliable and high-quality global chemical material supplier and manufacturer. It has more than 12 years of experience providing ultra-high quality chemicals and nanotechnology materials, including tantalum carbide, nitride powder, graphite powder, sulfide powder, and 3D printing powder. If you are looking for high-quality and cost-effective tantalum carbide, you are welcome to contact us or inquireat any time.
