As a leading supplier and manufacturer of machined products – we stock several unique refractory metals. One such metal that we stock is tungsten. Perhaps the most durable in our repertoire, tungsten metal is used across hundreds of industries in a huge variety of applications – from alloys and aeronautics to electronics and the production of super-hard materials.
But why is tungsten so important?
Here we outline six advantages of tungsten metal, which help to explain why it is used so widely.
1. Resistance to high temperatures
Of all metals in their purest form, tungsten has the highest melting point (3422°C). This can be hugely beneficial in certain situations (particularly when compared to other more common metals). For example, it makes tungsten an excellent material for high-temperature environments – and this is why it is so widely used in the aerospace, automatic and construction industries.
Tungsten metal is also regularly used to create alloys and superalloys. Its extremely high melting point and resistance to thermal creep help to strengthen the alloy, making it suitable for more thermally intensive applications, where other metals would fail.
Tungsten benefits from a very high density. In fact, at 19.3 g/cm3, it is amongst the highest of all metals, with tungsten’s density measuring approximately 19.3 times higher than that of water and 1.7 times higher than that of lead.
As a result of this property, tungsten can hold much more weight in a smaller package – and is commonly used for applications were mass is required in small sizes. For example, due to the high density of tungsten, it is a fantastic option for making racing car ballast, aircraft ballast and kinetic munitions – which must be small and streamlined, yet capable of transferring lots of energy.
It’s also used as an effective, alternative metal for jewellery-making. Tungsten’s density is extremely similar to that of gold (i.e. tungsten being just 0.35% less dense) – yet it’s much cheaper to buy. Therefore, since the 1980s, it has frequently been used to make counterfeit gold bars, either by plating a tungsten bar with gold or drilling holes in a genuine gold bar and adding tungsten rods.
Lastly, thanks to its high-density, tungsten is regularly employed to create heavy metal alloys. One particularly good example is high-speed steel, which can contain as much as 18% tungsten. However, tungsten’s density can also prove useful when combined with nickel, copper, iron and more.
3. Low thermal expansion
Tungsten has the lowest coefficient of thermal expansion of all pure metals. Compared to common manufacturing materials (e.g. steel), this gives it the benefit of added stability under extreme heat. It has a structural solidity unmatched by other metals and is especially useful when rigidity at high temperatures is required – such as in tungsten carbide cutting tools or jet engine turbine blades.
4. Electronic structure
Due to its conductive properties and relative inertness, tungsten metal is widely used in the electronics industry and environments involving high levels of radiation. For this reason, along with its very high density, tungsten is one of the main sources of metal for X-ray targets and other high-energy radiation shielding – as the relatively inert, very high-density material is difficult for x-rays to penetrate. Tungsten metal also frequently finds use in electrodes, conductors and metallic films.
Tungsten is highly resistant to corrosion and can be used in a range of corrosive environments and outdoor applications. For example, it is particularly useful when prolonged exposure to corrosive substances – such as water, acid, or solvents – is likely.
A commonly-encountered corrosive environment, which many metals are unable to deal with, is a marine environment. Salt water, in particular, is extremely corrosive to many metals. However, when alloyed with other metals, the resistance of tungsten metal makes it extremely suited to such a harsh environment, enabling it to be used in shipbuilding, fishing lures and jewellery.
6. Strength in fabrication
Tungsten is an extremely robust metal, with the highest tensile strength of all pure metals. While this can make it brittle under certain circumstances, when it comes to the process of metal fabrication, tungsten’s rigidity means that it can be drawn into very thin wires without fracturing.
Perhaps the most obvious example of this is tungsten’s use in the context of light bulb filaments. In this particular application, extremely thin wires must be heated to extremely high temperatures, in order to emit light – and tungsten’s high melting point is a crucial factor in allowing this to happen.