Tungsten is an extremely strong, resistant, dense, hard and heat resistant metal that is often alloyed with other metals and materials to further improve strength, melting point and hardness properties. Most tungsten products are alloyed with some sort of metal, including steel, carbide, nickel, copper and iron.
The most popular tungsten alloy is tungsten carbide, which is a very strong metal used in mining, construction and industrial machinery. It accounts for 65% of the total tungsten consumption worldwide. Other alloy grades are used for weapons including bullets, body armor, cannon shells, grenades and missiles. Tungsten alloys are also used in musical instrument strings, heat sinks, armaments, turbine blades, weights, ballasts, watch/clock components, among many other products.
The defense, aerospace, marine, mining, construction and consumer product industries all employ tungsten alloys to fabricate or coat products. Tungsten alloy coatings extend the life of products like tools by many years and protect items like jewelry from scratching. Some rarer applications include organic dyes, pigment phosphors, cathode-ray tubes and x-ray screens, which are all made from tungsten-based chemicals. Tungsten alloys are very dense and are useful when fabricating kinetic energy penetrators, counterweights and flywheels.
Tungsten in raw form is a fine, grey powder. It is often combined with another metal, and then sintered to form different forms, which include bar, rod, sheet and wire. The sintering process involves packing the powder into molds and heating them in an industrial oven. The powder becomes adherent and denser, allowing a solid metal shape to form when the metal has cured and come back to room temperature. The three most popular tungsten alloys for consumer goods are tungsten-thorium, which increases the efficiency of electron discharge tubes and improves creep strength to wire in high temperatures, tungsten-molybdenum and tungsten-rhenium.
Some tungsten alloys contain mostly tungsten, generally about 90 to 98%. These are called tungsten heavy-metal alloys, and are considered nearly pure tungsten. These grades are used for warheads, computer disk drives, isotope containers, gyroscope components, as well as weight distribution adjustment for boats and racecars.
Heavy-metal tungsten alloys usually contain small amounts of cobalt, nickel, iron and copper. Tungsten by itself has many good qualities, but its high density, poor ductility in cold temperatures and tendency to strongly react with air are some of its less desirable qualities. Alloying tungsten with different metals improves some of these shortcomings and broadens tungsten’s applications in different environments.