How Tungsten Is Used

Tungsten Applications

Tungsten has the highest melting point among all metallic elements. Its density is high and is comparable to that of gold. Tungsten is very hard. Tungsten carbide’s hardness is nearly equal to that of diamond. Furthermore, tungsten provides good electrical and thermal conductivity and exhibits a low coefficient of thermal expansion. It is widely used in alloy production, electronics and the chemical industry.

Alloy Field

Tungsten’s high hardness improves the strength, hardness and wear resistance of steel. It plays an important role as an alloying element and is widely employed in various steel productions. Common tungsten steels include high‑speed steel, tungsten steel and tungsten‑cobalt magnetic steel. These steels are used mainly in the manufacture of tools such as drills, milling cutters, drawing dies and forming dies.

Tungsten Carbide-based Hard Alloy

Tungsten carbide shows high wear resistance and heat resistance. Its hardness is nearly equal to that of diamond. It is frequently employed in the manufacture of hard alloys. Currently, tungsten carbide-based hard alloys represent the largest consumption sector for tungsten. The carbide is manufactured by powder metallurgy. It is produced by sintering tungsten carbide powder with a metallic binder (e.g. cobalt, nickel, molybdenum) in either a vacuum furnace or a hydrogen reduction sintering furnace. These hard alloys are typically divided into four types: tungsten carbide with cobalt, titanium carbide with cobalt and tungsten carbide, titanium carbide, tantalum carbide with cobalt, and steel-bonded hard alloys. They are mainly used in the production of cutting tools, mining tools and drawing dies.

Heat and Wear Resistant Alloys

Tungsten has the highest melting point among all metals and very high hardness. Consequently, it is used to produce alloys that resist high heat and wear. For example, alloys containing tungsten, cobalt, chromium and carbon are used to manufacture parts requiring high strength and wear resistance. These parts are used in aerospace engine valves and turbine impellers. Tungsten combined with other high‑melting-point metals is also employed to produce high‑strength components for rocket engine nozzles.

High-Density Alloy

Owing to its high density and hardness, tungsten is suitable for manufacturing high‑density alloys. Based on composition, properties and applications, these alloys are divided into series such as W‑Ni‑Fe, W‑Ni‑Cu, W‑Co, W‑WC‑Cu, W‑Ag and others. They exhibit high weight, high strength, radiation absorption capability, thermal conductivity and a low coefficient of thermal expansion. They also possess good electrical conductivity, weldability and ease of processing. They are widely used in aerospace, military, oil drilling, electrical instrumentation, medical and other industries. These alloys are applied in the manufacture of contact materials, balance hammers, armoured parts, fins, rudders and control components such as switches, power switches and spot welding electrodes.

Electronics Sector

Tungsten is widely used in the electronics and energy industries because of its high plasticity, low evaporation rate, high melting point and high electron emission capability. For example, tungsten is used in the manufacture of incandescent filaments for incandescent and halogen lamps owing to its high luminous efficacy and long operational life. Tungsten wire is used to produce hot cathodes, grids and various electronic instruments. Its properties also allow its use in gas tungsten arc welding.

Chemical Sector

Tungsten compounds are used as catalysts and in the production of inorganic pigments. For example, tungsten disulphide is employed as a lubricant and catalyst in the synthesis of petrol, tungsten oxide is used in paints, and calcium or magnesium tungstate is utilised in fluorescent powders.

Other Sectors

Tungsten’s thermal expansion closely matches that of borosilicate glass. Consequently, it is used in the manufacture of glass-to-metal seals. Its low sensitivity permits the production of high‑purity tungsten jewellery. Additionally, tungsten is used in nuclear medicine and in certain instruments that utilise tungsten wire.