The Knowledge About Niobium Carbide Properties And NbC Application

Niobium carbide is an inexperienced cubic crystal with metallic luster and  belongs to the sodium chloride kind cubic crystal gadget. Niobium carbide is a  metallic carbide with the chemical formula NbC.

Properties of Niobium Carbide:

The melting point of niobium carbide is 3500 ℃, and its microhardness is>  23.five Gpa (> 2400 kg / mm2), which is tougher than corundum. Niobium  carbide has an elastic modulus of 338000 N / mm2, a thermal growth coefficient  of 6.65 × 10 ^ (-6) / k, a thermal conductivity of 14 w / (m · ok), and a  resistivity of 35 μΩ · cm.

Niobium carbide is insoluble in bloodless and warm hydrochloric acid,  sulfuric acid, and nitric acid, and it’s far soluble in warm hydrofluoric acid  and nitric acid combined solution. It’s miles strong at 1000 – 1100 ℃, and  quickly oxidizes to niobium pentoxide above 1100 ℃. Niobium carbide is fusible  in compounds such as titanium carbide, zirconium carbide, and tungsten carbide,  and together bureaucracy a homogeneous stable solution mixture.

Fields of NbC application:

1.NbC application in composite substances

(1) Composite ceramics

As one of the raw substances of multiphase ceramic substances, the synthetic  multiphase ceramic materials are frequently used within the fields of  damage-resistant components, slicing equipment and electrodes due to their  excessive hardness, excessive melting factor, splendid chemical balance, and  conductivity.

(2) Hard alloy

Not simplest can be used as an inhibitor of cemented carbide grain boom but  can also form a third dispersed phase excluding WC and Co together with other  carbides, which can notably improve the thermal hardness and resistance to  thermal shock Antioxidant ability. Because niobium carbide has the advantages of  enhancing the hardness of the alloy and improving the fracture durability of the  alloy, it can be used to prepare hard alloy reducing tool materials with  exceptional slicing performance.

(3) Surfacing electrode

The difficult niobium carbide tough section enters the shape of the surfacing  layer, in order that the welding layer has a better wear-resistant skeleton, and  the wear resistance is greatly advanced. The damage resistance of this electrode  surfacing is 1.2 – 1.eight times higher than that of quenched 45 steel (HRC50),  and 2.4 – 3.6 instances higher than Fe-Cr-C-B type put on-resistant  alloy.

(4) Aerospace additives

It is used as instruction cloth for parts of many aerospace equipments  including turbine rotors, fuel rudders, blades, engine nozzle linings, and  structural elements of nuclear reactors.

2. NbC application in coating materials

(1) mold metal surface coating

As a steel carbide, niobium carbide has high hardness, heat resistance, and  abrasion resistance. consequently, coating it on steel indicates that it may  improve the damage resistance of the mold surface.

(2) Coating of steel workpieces

The niobium carbide layer is compounded on the floor of the bottom of the  metallic workpiece, which greatly improves the surface hardness that could reach  HV2800 or higher, and at the same time, will increase the operating temperature  and tissue density of the workpiece, thereby extending its service  lifestyles.

(3) different niobium carbide coatings

The high-temperature components of the spacecraft are lined with niobium  carbide, which can drastically growth their provider life. In the electronics  industry, the material of the center layer of the electron emission tube makes  use of ultra-first-rate cobalt-containing niobium carbide, which has a  substantial effect on growing the emissivity of the gate surface, decreasing the  gate temperature and lowering the thermal emission of the gate, thereby  extending the electron emission tube’s existence.

3. NbC application in the production of metal niobium

We specifically make use of indirect discounts to produce metallic niobium.  The produced niobium carbide is used as a decreasing agent, which interacts with  niobium pentoxide to supply crude steel niobium, and then is subtle to gain  metallic niobium with higher purity. Besides, niobium carbide can without delay  lessen niobium pentoxide to form pure metallic niobium.