Advanced Ceramics – A Guide
Advanced ceramics are materials which exhibit an extensive range of properties and behaviours. They can be divided into two categories:
- Functional ceramics – which display specific electrical, electronic, magnetic or optical properties and performance
- Structural ceramics – which display mechanical and thermal properties and behaviours.
With the development of new ceramics these boundaries are becoming increasingly blurred, as can be seen, for example, in bio-ceramics which exhibit both structural and functional properties.
Ceramic materials are increasingly required to operate in ever more demanding environments but their unique set of properties tend to be at the upper limits of performance requirements.
Ceramics are often used in hidden, niche or specialist components but are hugely important to the UK in that they unlock performance in a wide range of high-tech industries, including aerospace (jet engines) energy (fuel cells, batteries), automotive (brakes, sensors and engine components), telecommunications and IT (electronics), defence (rocket parts, antennas and armour), healthcare (artificial hips, teeth, etc.) and many other sectors where they are identified as the ‘only material that will work’.
Ceramics provide a unique combination of hardness, resistance, strength and high temperature operation not found in traditional alternatives such as metal alloys and polymers.
A good example of the benefits of ceramics are ceramic matrix composites (CMCs).
These comprise a ceramic body, reinforced by ceramic fibres, that typically exhibits significantly enhanced toughness. In addition they have the attractive ceramic properties of low density, high hardness, good compressive strength and excellent thermal and chemical resistance.
This makes CMCs ideal as lightweight replacements for alloys in high temperature aggressive environments, such as turbine engines and exhaust systems, where they can bring significant improvements in performance, emissions and fuel consumption.