Why isn't Tungsten Metal Used to Make Aero Engines?

Tungsten metal is the metal with the highest melting point in the world, with a melting point as high as 3380℃. In comparison, the melting point of iron is only 1538℃, and the melting point of nickel is only 1455℃. Therefore, the filament made of metal tungsten is used in the incandescent light bulbs we commonly use, because only this metal can withstand the huge heat generated when current passes through.

When we are talking about high temperature resistance, there may be no where we need to look for high temperature resistant materials but aero engines. After all, aero engines need to produce a large amount of energy through extremely violent combustion to drive the aircraft to fly, resulting in a temperature rise after the combustion chamber. It needs to be as high as 2000℃ or even higher.

But why we didn’t see tungsten metal in aero engines processing, even compounds containing tungsten？

• Characteristics of Tungsten Steel

 First of all, because the density of tungsten steel is higher than other steel materials, using tungsten steel to make engines will cause the engine to be too heavy. This will not only affect the fuel consumption and operating efficiency of the engine, but also affect the performance of the entire aircraft.

Secondly, tungsten steel is prone to brittle fracture at high temperatures. Environmental factors such as air pressure and temperature at high altitude will produce very high pressure and temperature in the engine. These pressures and temperatures can easily cause brittle fracture of tungsten steel. This is fatal for the use of engines such as aircraft and rockets.

• The scope of tungsten application

In addition to the limitations of the physical properties of tungsten steel, there are actually limitations on the scope of application of tungsten steel. Tungsten steel is mainly used in the manufacture of wear-resistant and corrosion-resistant industrial cutting tools and drill bits. These fields have high requirements on the hardness, toughness and wear resistance of the material, but are not very concerned about shortcomings such as brittleness at high temperatures. Therefore, it is less likely to use tungsten steel in high-temperature and high-pressure applications such as engines.

Therefore, even though tungsten metal has a high melting point, its shortcomings are equally obvious, that is, the density of tungsten metal is a full 19g per cubic centimeter, which is twice that of steel and four times that of titanium alloy. It is not a good choice in high-temperature and high-pressure situations such as engine manufacturing. Relatively speaking, the use of other materials such as titanium alloy is more suitable in these situations.