Promising Advancements in Environmental Barrier Coatings for CMCs
Ceramic Matrix Composites (CMCs) are one of the most exciting materials being developed for, predominantly, aerospace and energy applications. With the addition of fibers within the material’s composition, CMCs can withstand extreme temperatures, are resistant to oxidation, and are also light-weight compared to alternative materials.
The added benefit of reduced fuel consumption resulting from the above is also important, not only from a resource perspective but from an environmental one too. Given global initiatives to reduce emissions, CMCs can play a vital role in mitigating toxic gases emitted in the atmosphere.
That being said, one of the drawbacks of CMCs is cost. Despite their many advantages, CMCs remain expensive to manufacture, and widespread applications are therefore still limited.
Environmental barrier coatings (EBCs) are used to provide protection for CMCs against harsh environments, such as high temperature water vapor attacks; this can have further adverse effects such as corrosion. The EBC and CMC combination is already disrupting the market by allowing components to operate at higher combustion temperatures, and reaching greater power levels than before.
Air plasma spray/APS (thermal spray processing) is a popular manufacturing technique applied to EBCs, however there is still a lot of development going on in this area. One such encouraging development is being carried out at NASA’s Glenn Research Center. Here, the researchers have created an environmental barrier coating which provides a more simple and cost-effective solution to plasma spraying. Glenn’s new EBC allows for “steam oxidation life of at least 500 hours at 1482°C”, which is much more efficient than current alternatives. The center’s material affords high durability, less laborious manufacturing, corrosion protection and added lifespan to CMCs.
A positive outlook
This is a significant development in the area of EBCs, providing optimized material characteristics and also addressing one of the main barriers for CMCs, cost. These environmental barrier coatings show great potential to allow for further advancements of CMCs and progress innovation of these materials for greater market applications.
Materials engineers across the industry are continuing to innovate ways to make ceramic matrix composites more accessible and to improve their performance. Technological advancements, such as NASA’s, will continue to facilitate the growth of the CMC market- which is predicted to reach $25 billion in the next decade- and show a very promising future ahead for ceramic innovation!
If you want to find out more on the topic of CMCs, join us at Ceramics Expo on August 31 – September 1 2021, in Cleveland OH. Here, you can listen to expert speakers from GE Aviation, NASA and more speaking on the conference session Breaking Down Barriers of Entry for Ceramic Matrix Composites, as well as a host of other leaders from the industry speaking on a number of exciting panels. You can register for the free-to-attend conference and exhibition here.