Tungsten metal

Tungsten metal powder is a kind of metal tungsten in powder form, the colour is usually dark grey or black, with high melting point, high hardness, high density, etc. It plays a key role in alloy manufacturing, electronic industry, aerospace and aviation and many other fields.

Properties

Appearance: Usually silver-grey or grey-black powder with metallic luster.

Density: high density, about 19.3g/cm³, which makes tungsten powder has an advantage in some applications that require material density, such as for the manufacture of high-density tungsten alloys, counterweights and so on.

Melting point: the melting point is as high as about 3400℃, which is one of the materials with higher melting point among the metals, which determines that it has good stability and heat resistance under high temperature environment, and it can be used to manufacture high temperature components such as heating elements of high temperature furnaces and nozzles of rocket engines.

Boiling point: the boiling point is about 5555℃, the high boiling point makes tungsten metal powder not easy to volatilise at high temperature, and it can keep good performance.

Crystal structure: Body-centred cubic crystal.

Stability: At room temperature, tungsten metal powder is chemically stable and does not react with air and water. However, at high temperature, tungsten will react with oxygen, chlorine, nitrogen and so on. For example, when the temperature rises to 400℃, tungsten will rapidly react with oxygen to form tungsten trioxide; at about 500℃, tungsten reacts with chlorine to form tungsten hexachloride.

Solubility: tungsten metal powder is soluble in the mixed acid of nitric acid and hydrofluoric acid, and melts with the mixture of sodium hydroxide and sodium carbonate; slightly soluble in nitric acid, sulphuric acid and aqua regia; insoluble in water, hydrofluoric acid and potassium hydroxide.

Particle size characteristics: wide range of particle size, ranging from submicron to tens of microns. For example, the particle size of tungsten metal powder commonly used in industrial production is generally Fischer’s average particle size of 2~10μm, and for the high purity and ultra-fine particle size of tungsten metal powder required by special applications, the particle size can be less than 0.05μm. The particle size affects the performance of tungsten metal powder, and the particle size of tungsten powder will become coarser with the increase of the reduction temperature. And the size of particle size also affects the specific surface area, bulk density, rocking density and other parameters of tungsten powder.

Hardness properties: Tungsten’s hardness is the hardest among the metals, the hardness of sintered tungsten bar is 200~250, and the hardness of tungsten rod after rotary hammering is 350~400.

APPLICATIONS

Cemented carbide field:

Cutting tool manufacturing: tungsten metal powder is an important raw material for manufacturing cemented carbide cutting tools, such as turning tools, milling cutters, drills and so on. Cemented carbide tools have high hardness, high wear resistance and high heat resistance, and can maintain good cutting performance under high-speed cutting and heavy load cutting conditions, and are widely used in machining, automobile manufacturing, aerospace and other fields.

Mould Manufacturing: Used in the manufacture of stamping moulds, injection moulds, die-casting moulds and so on. These moulds play a vital role in industrial production and need to have high hardness, high strength and good wear resistance to ensure the service life of the moulds and the quality of the products.

Alloy material field:

Tungsten Alloy: Tungsten metal powder mixed with other metal powders (such as molybdenum, rhenium, iron, nickel, etc.) can be made into various tungsten alloys. For example, tungsten-molybdenum alloy has good high-temperature strength and creep resistance, commonly used in high-temperature furnace heating element, cathode of the electronic tube, etc.; tungsten rhenium alloy has a high melting point and good plasticity, and can be used to manufacture aerospace engine blades, rocket nozzles and other high-temperature parts; high-density tungsten alloy has a high-density, high-strength features can be used to manufacture counterweights, gyroscopes and so on.

Tungsten-copper alloy: both tungsten’s high melting point, high strength and copper’s good electrical conductivity, thermal conductivity, commonly used as electrical contact materials, electrode materials, electronic packaging materials. For example, in the high-voltage switch, tungsten-copper alloy contacts can withstand high voltage and high current impact, while ensuring good electrical conductivity.

Electronic industry field:

Electrode materials: due to its high melting point, high conductivity and good chemical stability, tungsten metal powder can be used to manufacture electrodes in electronic devices, such as the electrodes of incandescent lamps, electron tubes, field emission displays and so on. In these devices, the electrodes need to withstand high temperatures and high currents, tungsten electrodes can ensure the normal operation of the device.

Semiconductor manufacturing: In the semiconductor manufacturing process, tungsten metal powder can be used to manufacture sputtering targets. Through the sputtering process, tungsten atoms on the tungsten target are deposited on the semiconductor chip to form metal wires or electrodes to realise circuit connections inside the chip.

Aerospace field:

Engine components: High-temperature alloy materials made of tungsten powder can be used to manufacture key components such as blades, turbine discs, combustion chambers and other parts of aircraft engines. These components need to have good high temperature resistance, high strength and fatigue resistance under high temperature, high pressure and high speed working environment, and tungsten alloy materials can meet these requirements.

Spacecraft structural parts: Due to the high density and high strength of tungsten, tungsten alloy materials can be used to manufacture structural parts of spacecraft, such as the brackets of satellites, antenna reflectors, etc., which can improve the structural strength and stability of spacecraft.

Medical field:

Radioactive shielding: tungsten metal powder has the characteristic of high density, which can be used to manufacture radioactive shielding materials, such as medical X-ray protection equipment, radioactive drug storage containers, etc., which can effectively block radioactive rays and protect the safety of medical personnel and patients.

Medical devices: It can be used to manufacture orthopedic implants, surgical blades, needles, dental instruments and other medical devices. Tungsten alloy materials have good biocompatibility and corrosion resistance, and can exist stably in the human body for a long time.

3D printing field: As a metal powder material, tungsten powder can be used in 3D printing technology to create various complex shapes of parts, such as aerospace parts, medical devices, moulds, etc.

Thermal spraying field: In the process of thermal spraying and welding, tungsten metal powder can be used as a spraying material, which is used to form a wear-resistant, corrosion-resistant and high-temperature-resistant coating on the surface of the workpiece to improve the service life and performance of the workpiece.

Filter material field: tungsten metal powder can be sintered into filters with various porosities for filtering impurities and particles in gases and liquids, such as filtration equipment in petrochemical, pharmaceutical, food and beverage industries.