Niobium Carbide powder（NbC） 

Chinese name: niobium carbide

English name: Niobium carbide

Chemical formula: NbC

Molecular weight: 104.923

Relative density: 8.47

Lattice constant: a=0.447nm

Melting point: 3500 ℃

Density: 7.6g/cm ³ (25℃)

Microhardness:>23.5 Gpa (>2400 kg/mm2), harder than corundum

Elastic modulus: 338000 N/mm2

Thermal expansion coefficient: 6.65 × 10^(-6)/K

Thermal conductivity: 14 w/(m · K)

Heat of formation: - 140.7 kJ/mol

Specific heat capacity: 36.8 J/(mol · K)

Resistivity: 35 μ Ω·cm

Physical and chemical properties: niobium carbide is green cubic crystal with metallic luster, belonging to sodium chloride type cubic crystal system. It is insoluble in cold and hot hydrochloric acid, sulfuric acid and nitric acid, and soluble in hot hydrofluoric acid and nitric acid mixed solution.

Application field:

1) Refractory high-temperature materials; With good chemical stability and high temperature performance, it is a high melting point and high hardness material, widely used in refractory and high-temperature materials; It is stable at 1000~1100 ℃, and rapidly oxidized to niobium pentoxide above 1100 ℃. Niobium carbide is easy to melt in titanium carbide, zirconium carbide, tungsten carbide and other compounds, and together form isomorphic solid solution mixture.

2) As a carbide carbide carbide additive, it is a ternary and quaternary carbide solid solution component, such as WC-NbC-C ternary system. It can also be used as purple artificial gem.

3) Niobium carbide is a ternary and quaternary carbide solid solution component, which is used in combination with tungsten carbide and molybdenum carbide for hot forging dies, cutting tools, jet engine turbine blades, valves, tail skirts and rocket nozzle coatings.

4) Used for producing wear-resistant film and semiconductor film. It can also be used as raw material for the production of molybdenum carbide, as well as for the manufacture of special chrome-free alloys and engineering ceramics.

① Application in composite materials:

Composite ceramics: As one of the raw materials of composite ceramic materials, the composite ceramic material made of niobium carbide is often used in wear-resistant parts, cutting tools and electrodes due to its high hardness, high melting point, excellent chemical stability and conductivity.

Cemented carbide: not only can be used as an inhibitor of grain growth of cemented carbide, but also can form the third dispersed phase except WC and Co with other carbides, significantly improving the thermal hardness of cemented carbide and the ability of thermal shock resistance, thermal compression resistance and oxidation resistance. Niobium carbide can be used to prepare cemented carbide tool materials with excellent cutting performance due to its advantages of improving the hardness and fracture toughness of the alloy. In addition, niobium carbide can also be processed into purple artificial gemstones

Surfacing electrode: the hard niobium carbide hard phase enters into the structure of the surfacing layer, which makes the welding layer have a good wear-resisting framework, and the wear-resistance is greatly improved. The wear resistance of the wear-resistant alloy deposited with this electrode is 1.2-1.8 times higher than that of quenched 45 # steel (HRC50) and 2.4-3.6 times higher than that of Fe-Cr-C-B wear-resistant alloy. At the same time, the wear-resistant surfacing layer can be welded on the surface of the workpiece without preheating. The small cracks generated on the surface can release the stress of the surfacing layer and will not diffuse into the base metal. In addition, adding a small amount of niobium carbide into the steel strengthening phase in the process of steelmaking can achieve the effect of precipitation strengthening and fine grain strengthening, thus improving the comprehensive mechanical properties of the steel.

Aerospace parts: used as the preparation materials for many aerospace equipment parts, such as turbine rotors, gas rudders, blades, engine nozzle liners, and structural parts of nuclear reactors.

② Application in coating materials:

Surface coating of die steel: As metal carbide, niobium carbide has high hardness, heat resistance and wear resistance. Therefore, coating it on steel can improve the wear resistance of the die surface.

Coating of metal workpiece: Niobium carbide layer is compounded on the surface of metal workpiece substrate to greatly improve its surface hardness, which can reach more than HV2800. At the same time, the working temperature and tissue density of the workpiece are increased, thus extending its service life. Niobium carbide coating can be realized on the surface of cast iron piston ring by chemical liquid deposition, and the coating is firmly combined with the base material; The coated piston ring has both good pocket oil storage structure and high hardness, which can significantly reduce the sliding friction coefficient of non-lubricating medium and diesel oil lubrication, greatly improve its wear resistance, reduce the friction loss of diesel engine and improve the performance of diesel engine.

Other niobium carbide coatings: the use of niobium carbide coatings on high-temperature parts of spacecraft can significantly improve their service life. In the electronic industry, the intermediate layer material of the electron emission tube is made of ultra-fine cobalt-containing niobium carbide, which has a significant effect on improving the emissivity of the grid surface, reducing the grid temperature and reducing the thermal emission of the grid, thus extending the life of the electron emission tube.

③ Application in the production of metal niobium: China mainly uses indirect reduction method to produce metal niobium. First, the produced niobium carbide is used as a reducing agent to react with niobium pentoxide to produce crude metal niobium, and then refined to produce high purity metal niobium. In addition, niobium carbide can also directly reduce niobium pentoxide to produce pure niobium metal.

Market analysis of key countries and regions:

Europe and the United States: At present, the niobium carbide industry in Europe and the United States (including Western Europe, North America, South America, etc.) has entered the late stage of rapid development or the early stage of maturity, especially in the United States, Brazil, Germany, the United Kingdom, Switzerland, Canada and other regions. The niobium carbide industry is gradually mature, with high product quality, sufficient or surplus supply, and market demand is gradually saturated or declining. The entire industry is in a highly competitive situation.

Storage conditions: inert gas anti-static packaging should be sealed and stored in a dry and cool environment, and should not be exposed to the air for a long time.