Durability Coatings
Durability Coating
A new coating composition which:
- Is more durable than standard coatings
- Enables higher operating temperatures
- Can improve efficiency of gas turbine operation
What is the Durability Coating?
STS have identified a coating composition that has shown superior durability in comparison to a standard thermal barrier coating (TBC). This opens up completely new market perspectives based on the advanced protection properties of the coating. The composition is more resistant to very high temperatures compared to standard thermal barrier coatings, therefore could enable higher operating temperatures enabling improved efficiency and could reduce maintenance costs.
Why is it better than standard coatings?
The current material of choice for a TBC is based on yttrium stabilised zirconia (YSZ). This material has a plurality of technical advantages, but when it is exposed to temperatures above 1250ºC it becomes unstable. Consequently the coating suffers irreversible damage and eventually will fall off. It is the objective of the industry to find a coating composition or structure which will enable the operation at temperatures beyond the limiting 1250ºC.
The novel coating composition was discovered as a by-product of the sensor coating development which is the core technology of the business. The composition has been shown to reduce the development of cracks caused by severe thermal exposure. The coating can be deposited using the current industrial techniques and is a slight modification from the widely used coating technology at present.
Has the coating been applied to operating components?
The coating has been trialled in a large gas turbine for power generation in the UK where it served for 4000 hours. The STS coatings passed the maintenance checks whilst the standard reference coatings failed indicating the potential reduction in maintenance costs if employed on existing engines.
Has the coating been tested?
The coating has been tested in thermal gradient cyclic tests with ultra high surface temperatures, around 1350°C, alongside standard YSZ coatings. While the standard TBC showed significant surface delamination under similar test conditions due to the increased temperature over normal operation. The STS coating showed a smooth surface and no noticeable damage.
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