Aerospace industry
Reducing structural weight is one of the major ways to improve aircraft performance. Lighter and/or stronger materials allow greater range and speed and may also contribute to reducing operational costs. The most effective way to reduce aircraft structural weight is to reduce the density of structural materials. Ceramics are increasingly being used in commercial and military aircrafts and have been used in space shuttles for many years. Ceramic materials are generally lighter than metals, and this low mass makes them highly appealing to the aerospace industry. However, the cost of working with an advanced ceramic material is such that a clear advantage must be established by using it. Once a benefit has been identified for a product or system (e.g., being able to run at a higher temperature or increased electrical activity), a range of ceramics is available. Advanced ceramics underpin the electronics industry, and therefore such electrical components, including sensors, antennas, capacitors and resistors, are getting increasingly smaller and more capable. Therefore, this is a major area of development for advanced ceramics. Moreover, structural ceramics (crystalline inorganic non-metals) are used in aerospace as thermal barrier coatings (TBCs) in the hot part of the engine. In addition, these materials are being used in composites either as reinforcement and/or as a matrix such as in ceramic matrix composites (CMCs). Being lightweight and tough tends to be a main driver for using a ceramic composite. Ceramics are lighter than most metals and stable at temperatures substantially above high-grade technical plastics. As a result of these and other properties, structural ceramic applications include thermal protection systems in rocket exhaust cones, insulating tiles for the space shuttle, missile nose cones, and engine components. Finally, technical ceramics have been used for various parts of the engine for the past 30-40 years, but a lot of activity currently surrounds the development of silicon carbide (SiC/SiC composites) for use in jet engine turbines, mainly concentrated on the turbine blades. The main driver is fuel efficiency, as engineers seek to run the jet engine without the need for cooling channels that currently stop the metal alloy blades from melting. If the blades were made of ceramic composites, which could deal with temperatures of 1,500-1,600°C, the engine could run at higher temperatures. Energy efficiency would therefore increase, which leads to less fuel and the airplane’s ability to fly further or more efficiently.