Coatings: The Hidden Heroes of Modern Engineering
Jet engines are an incredible engineering achievement, yet they face a critical challenge. The air entering them is hotter than the melting point of the engine’s metal parts, which is problematic. The air can reach temperatures over 1,000°C, far exceeding the tolerance of many materials.
To address this, designers have applied heat-resistant ceramic coatings to engine blades. Researchers are now working on even stronger coatings to allow engines to run at even higher temperatures. Increasing the engine’s temperature by just 30°C can save up to 8% in fuel consumption, and significantly reduce CO2 emissions.
Coatings are powerful tools that transform materials, enhancing their functionality and durability. While often unnoticed, they are essential in boosting the performance of high-end machines and protecting expensive equipment in extreme conditions.
Dr. Ben Beake and his team are pushing these coatings to their limits, testing their durability under extreme conditions. The testing process isn’t always smooth. Dr. Beake remembers once telling a missile manufacturer, “We’ve broken your coating,” which led to a heated reaction from the company.
In addition to testing at high temperatures, Micro Materials uses a unique “woodpecker” device— a tiny diamond stylus that taps a coating repeatedly. This tests the coating’s durability by simulating real-world wear.
Recently, the company partnered with UK-based Teer Coatings to test coatings for satellite components, including gears and bearings. These coatings need to perform in both the harsh conditions of space and the moisture-rich environment of Earth. According to Xiaoling Zhang, the tests have been successful.
Coatings also help address issues beyond just machinery protection. For example, biofilms—clumps of bacteria that form inside pipes—grow faster in space. This could affect water supplies and equipment on spacecraft. To combat this, researchers at MIT, led by Kripa Varanasi, have developed coatings that prevent biofilm formation. Their work was tested aboard the International Space Station with positive results.
These biofilm-resistant coatings make surfaces slippery, reducing bacterial buildup and preventing mechanical failures. Varanasi’s work also extends to products like toothpaste tubes, where a similar coating ensures every last bit of paste is used up.
Coatings can also have a significant impact on industrial equipment. At the Norwegian University of Science and Technology, Nuria Espallargas and her team created a silicon carbide-based coating for tools used in aluminum manufacturing. This non-stick solution helps prevent molten aluminum from sticking to equipment, though the exact mechanism behind it is still a mystery.
For companies like Atlas Machine and Supply, this coating has been a game-changer. It has extended the lifespan of their equipment, saving millions in rebuild costs. What once required rebuilding every two days now lasts a week, cutting costs from $4.5 million to $1.3 million annually.
However, coatings don’t always work as planned. In some cases, like with fire-resistant paint on car park structures or coatings on commercial ships, issues arise. In particular, ships often face biofouling, where barnacles and other sea life attach to the hull. This increases friction and fuel consumption.
Choosing the right coating for each situation is crucial. Factors such as the environment and usage patterns affect the choice of coating. Incorrect choices can lead to costly repairs.
Despite the challenges, there are still many opportunities to improve coatings. Researchers continue to explore new ways to enhance the performance and longevity of machines, infrastructure, and technology in the future.