Ceramics, a natural, versatile and high performance material, used since ancient times through to today. Over the centuries, it has undergone profound developments, to the extent that it now can be used in high-end applications that require particular technical and mechanical feature. Among these innovative ceramic materials there are ceramic matrix composites.
This is a class of structural ceramic materials that combine the traditional features of ceramics, such as resistance to high temperature, resistance to environmental agents and hardness, with new properties such as optimal mechanical strength, excellent resistance to wear and good dimensional stability.
One of the fields in which this technological evolution has gained ground is the automotive sector, where traditional materials are now replaced with innovative materials. This applies, for example, to brakes, where manufacturers have looked into solutions that can guarantee low density with a high friction coefficient. The reason behind this choice is the general need to reduce the overall weight, combined with a demand for braking performance, which needs to be strong, especially in the cases of racing cars, trains and planes. In this context, ceramic material composites are the ideal solution to meet these demands, because they can be designed.
“Ceramic matrix composites are materials that offer exceptional thermal and mechanical properties, able to resist temperatures far higher than typical values of steels and super alloys. Ceramic matrix composites reinforced with ceramic fibres also features the extraordinary property of mechanical behaviour known as “quasi-ductile”, even though made up of two materials (matrix and ceramic fibre) known to be intrinsically fragile. This does not mean that this type of composite can be laminated or forged, but they can definitely tolerate mechanical processes, such as threading. Ceramic matrix composites reinforced with ceramic fibres are used in applications that reach temperatures of over 1200 °C ” explained Prof. Monica Ferraris of the Turin Polytechnic University, Department of Applied Science and Technology.
As well as the automotive and motor sport sector, technical ceramics are also used in the aerospace sector, an industry that requires materials with structural performance able to resist mechanical stress and wear even in very extreme temperature and pressure conditions.
At the conference “The Future of Ceramic Industry” held in the USA, the subjects discussed included the use of ceramics in producing the exhaust cone of the reactors on planes. Engines that are produced today can reach much higher temperatures than in the past, for reasons of efficiency, but this requires the use of materials that offer heat resistance levels beyond those of super alloys with a titanium or nickel base. Numerous tests were conducted on the ground and in flight, with results exceeding expectations, thus opening up major areas for development also in the civil aviation sector.
In light of the continuous innovations in materials engineering, technical ceramics now represent one of the most efficient materials of our time, opening up possibilities for applications that until a few years ago were unthinkable.