What are tungsten carbide coatings?
Tungsten carbide is a chemical compound of tungsten and carbon, which appears as a light grey powder in its most basic form. With an extremely high melting point, tungsten carbide is often used to create thermal spray coatings. Through the high velocity oxygen fuel process, tungsten carbide powder is injected into a hot gas stream. The jet of powder and gas is then directed towards a surface, producing a tungsten carbide coating.
What are the benefits of tungsten carbide coatings?
Tungsten carbide coatings can provide a number of beneficial properties to surfaces. When applied through the high velocity oxygen fuel process, the properties of the coating can be tailored through volume fraction and grain size. Whether a component requires increased hardness or improved strength, the characteristics of the coating can be tailored to the application. This is particularly beneficial in the aerospace industry, where there is a wide range of critical components that have a specific set of requirements.
How can tungsten carbide coatings be used in the aerospace industry?
The aerospace industry is one of the largest consumers of HVOF tungsten carbide coatings. With aerospace products being exposed to such extreme environments, it is vital that they can withstand these conditions. Below, we have explored how tungsten carbide coatings can be used to strengthen different aircraft components.
Landing gear
To provide adequate support to an aircraft throughout the duration of its flight, landing gear must be able to withstand enormous pressure. Even during take-off, the landing gear components need to be strong enough to support the heavy load of the aircraft, as well as the weight of a full tank of fuel. Whilst landing gear is designed to absorb most of this energy, it is common for components to develop fatigue.
Tungsten carbide coatings can improve the wear resistance of landing gear components, including the axles, pins and bearings. This will help to improve the strength of the landing gear, providing passengers with a more comfortable experience throughout take-off and landing.
Turbine engines
Without regular maintenance, turbine engines can develop a number of complications. One of the most common problems is caused by the burning of the aircraft fuel. During this process, sodium sulphate gas is released which attacks nearby metal components, including the blades of turbine engines. This can quickly lead to sulfidation, causing large blisters to form on the surface of the metal. At this point, component failure is often unavoidable.
Tungsten carbide coatings can provide corrosion resistance to turbine engine components. In fact, it has been proven that tungsten carbide provides fourteen times more corrosion resistance than stainless steel, significantly increasing the longevity of turbine engines.
Flap tracks
Whilst designed to withstand the pressures of flight, it can be challenging to minimise the fatigue of flap tracks. When flap tracks are down, they have a huge amount of wind pushing against them. When the flap tracks are up, they are gradually wearing away the flap tracks slots. Over time, this constant pressure can cause flap tracks to become damaged, and can even lead to cracking.
HVOF tungsten carbide coatings can be used for effective fatigue control. By tailoring the coating characteristics, tungsten carbide can provide increased strength to flap tracks, improving the fatigue life of the components.
Improve the longevity of aerospace components
EP Coatings specialises in the production of thermal spray coatings for the aerospace industry. Through rigorous testing, we have identified tungsten carbide coatings as one of the most effective solutions for aircraft components. With a team of experts, we will develop an understanding of your core challenges. This will allow us to create a HVOF tungsten carbide coating that is tailored to your requirements.
To find out more about our development process for aircraft components, get in touch.