When you’re looking for tough materials with high resistance to heat and most types of wear, refractory metals are most likely the answer.
There are five elements in this category, and the one with the highest melting point is tungsten – which also has one of the highest densities, along with many other practical properties.
This makes tungsten stand out as one of the most popular metals, but why is it so useful? Here are six benefits of tungsten metal that have earned its proficient reputation.
1) High melting point
With a melting point of 3414°C and a boiling point of at least 5555°C, it’s safe to say that tungsten has one of the highest levels of heat resistance of all metals.
The ability to withstand excessive temperatures without melting or boiling makes this element useful in high-temperature environments, from furnaces and kilns to aeroplane and rocket engines.
Tungsten metal is also often used to create alloys, increasing the resistance of the alloyed metal and making it strong enough to resist deforming under the stress of constant heat (‘thermal creep’).
2) Low thermal expansion
Another benefit of its heat resistance is that tungsten also has the lowest thermal expansion co-efficient of all pure metals. This means the metal remains solid and stable even in extreme heat.
Rigid tungsten metal won’t expand under high temperatures, nor will it crack from the strain of sudden temperature changes (‘thermal shock’).
The stability of this metal in these situations makes it ideal for working with everything from jet engine turbines to neural probes, from carbide cutting tools to silicon wafer testing.
3) High tensile strength
While pure tungsten is brittle, the ductile material can be combined with other elements to create super-hard metal compounds like tungsten carbide.
It has an average rating of 7.5 out of 10 on the Mohs mineral hardness scale, which puts diamond at the top – but tungsten carbide becomes almost as hard and scratch-resistant at 9.
The high-tensile strength of tungsten metal makes it a popular choice for mining and metalworking tools, used for cutting, milling, and grinding without fracturing.
4) High-density heavy metal
With a density of 19.3g/cm3 (grams per cubic centimetre), tungsten metal has a similar density to the precious metal gold – a fact that’s been used for fakery in the past!
While lead is often the go-to when you think about the heaviest element, at 11.29g/cm3 it’s actually far less dense than heavy metals like tungsten.
Having a high density is important when packing more weight into a smaller package, such as ballast for aircraft and racing cars, and kinetic missiles used in military operations.
Considering the fact that the most widely known use of tungsten metal is in light bulb filaments, it might surprise some people to know that it’s actually not the best conductor of electricity.
What makes it the best electrical conductor for certain applications is its high thermal conductivity. Tungsten can carry enough of an electrical current and maintain it through conditions of extreme heat to make it the most practical choice in many industries.
These include electronics and radiation equipment – tungsten’s high density also helps with radiation shielding as it’s difficult for X-rays to penetrate.
6) Corrosion resistance
Made up of five stable isotopes, tungsten is naturally inert, meaning that it won’t chemically react with other elements it’s exposed to. While it oxidises in air at elevated temperatures, tungsten metal is highly resistant to corrosion.
In harsh environments where other, less stable, metals would easily corrode, tungsten and its alloys can resist everything from acids to salt water for prolonged periods of time.
This is another property that makes tungsten useful in electrical conductor applications, where metal components must resist corrosion and high temperatures. It also allows tungsten metal to be used in varied situations from jewellery to fishing lures.
As you can see, tungsten is one of the most useful refractory metals. Dense and hard, yet ductile, and highly resistant to heat, corrosion, and thermal expansion – tungsten has all the qualities needed for high-pressure and high-temperature environments.
Despite having so many benefits and potential uses, tungsten metal is relatively affordable and easy to purchase online. So, if you’re looking for heavy metals or alloys for high-performance parts and fittings, look no further than tungsten.