Application Spotlight: Abradability
At A&A Coatings, we offer high quality abradable coating solutions that are suited for a wide range of industries. If your thermal spray coatings have the right amount of abradability, you can reduce fuel consumption, reduce emissions and even improve safety in your turbomachinery. Whether you own power generation steam or gas turbines, or aviation gas turbines, you can be sure that we have abradable materials for all your clearance control applications. Let’s find out more about our coatings for abradability applications.
Why Opt for Thermal Spray Coatings with Increased Abradability?
First, you should note that abradable coatings are produced to preferentially abrade upon contact with a mating part. This type of thermal spray coating typically has low structural integrity and that’s why they are readily abraded when another moving surface (with higher structural integrity) comes into contact with it. You can rest assured that abradable coatings will not damage the mating surface. In addition, below is a quick look at the various benefits that abradable coatings offer:
- Blade and tip wear are prevented
- Low coefficient of friction
- Stellar internal strength
- Can resist thermal shock
- Ideal balance of erosion resistance and abradability can be achieved
- High degree of abradability
- Impact resistant
- Able to resist oxidation well
Common Abradable Coating Structures
Next, there are different abradable coating types. Each of them cater to different operating temperatures, mating materials and corrosive environments. The common coating structures include:
- Uniform, dense and structured: These coatings often include additives such as boron nitride, bentonite, graphite and polymers. These additives can provide some degree of dry lubrication and weaken the matrix material of the coating.
- Very porous: This type of coating can contain many unmelted or unreacted particles. To avoid producing inferior coatings, careful selection of spraying parameters is imperative.
Understanding the Main Applications of Abradable Coatings
Thermal sprayed abradable coatings are often applied to improve gas path clearance control in gas turbine engines. In most cases, these engines are manufactured with minimal clearance, especially in the gas seal locations. When you use abradable coatings to keep clearances to a minimum, you can lower the risk of catastrophic failure, enhance gas turbine engine efficiency and more. With that in mind, below is a quick summary about what we can do for the main components that have just been discussed.
- Steam turbines
A&A Coatings can apply abradable coatings on your steam turbine assembly, including parts such as steam flow path seals, balance piston seals and shaft seals.
- Power generation gas turbines
Our coatings suit a wide range of power generation and mechanical drive applications. What’s more, you can increase compressor efficiency up to 5% by applying our clearance control coatings on your industrial gas turbine compressors.
- Aircraft gas turbine engines
Aircraft propulsion engines, be it turboshaft engines or civil/military turbofan engines, can log millions of flight hours annually. That’s why our coatings are designed to improve operational safety and efficiency. Our coatings can be applied on rotor path linings, bearing air seals, intermediate pressure compressor seals and more.