Technical ceramic

0.8-45 usd/kg
Circularity potential
Ultra low
Strength
High
Production energy
Very high
Stiffness
Very high
Embodied CO2
High
Density
High

Technical ceramics, also called advanced ceramics, are a group of very hard, inert, and dimensionally stable oxides, carbides and nitrides. They are formed from powder, solid or gas, into engineering components and coatings used in some of the most demanding and extreme applications.

The chemical composition of these materials is carefully controlled and adjusted to suit the requirements of an application. 3D shapes are formed by pressing a powder into shape, CNC machining and sintering (fusing with heat). A range of processes exist for this, including those suitable for high volumes, such as die pressing (compacting into a mould) and ceramic injection moulding (a binder is added to the powder to help it flow into the mould under pressure). Isostatic pressing is used for smaller volumes. Powder is placed into a flexible mould (membrane) and pressure is applied by liquid or gas. With cold isostatic pressing (CIP), a second sintering step is required. In the case of hot isostatic pressing (HIP), the powder is sintered as it is formed, resulting in superior mechanical properties and surface finish.

With these processes it is possible to make parts with extremely precise dimensions and very thin wall sections. Applications span aerospace, architecture, military, industrial, automotive, electrical and medical applications.

As well as bulk 3D parts, technical ceramics are applied as coatings onto metal, glass and plastic by vacuum deposition. This technique is used by many industries – tooling, solar panels, medical, lighting, consumer products, jewellery and so on – to create thin film ceramic coatings for enhanced protection, performance and colour.


Sustainability concerns
Non-renewable ingredients
Raw material generates polluting by-products
Low circularity potential


Aluminium oxide (Al2O3), alumina, is the most common technical ceramic, with a good balance of electrical and mechanical properties, wear resistance and corrosion resistance. It is predominanyly used as an electrical insulator, such as in spark plugs, but also utilised in mechanical and pump seals, nozzles, prostheses, medical implants, labware, armour and abrasive media. Purity ranges from 85% to 99.9%. Mechanical properties, hardness and chemical resistance all increase with purity. Colour progresses from pinkish-brown in low purity types through white and ivory at 99.9%.


Design properties
Cost usd/kg
0.8-3
Embodied energy MJ/kg
50-55
Carbon footprint kgCO2e/kg
2.5-3
Density kg/m3
3700-3970
Tensile modulus GPa
350-390
Tensile strength MPa
260-300
Flexural strength MPa
310-379
Compressive strength MPa
1750-2620
Hardness Mohs
9
Poissons ratio
0.23
Thermal expansion (µm/m)/ºC
7
Thermal conductivity W/mK
12-32
Temperature min-max °C
"-250 to 1500"
Thermal
conductive
Electrical
insulator