Advanced ceramics have exceptional mechanical properties compared to metals and plastics. Compressive strength is very high for all groups of advanced ceramics, but other properties, such as density, hardness, resistance to wear, shock resistance and flexural strength vary from one type of ceramic to the next.
Description
Density is the mass of a material per unit volume. The unit of measurement can be expressed in different ways (g/cm3, kg/m3, etc.) according to the reference system used.
Advanced ceramics have densities that vary between 2.5 g/cm3 and approximately 6 g/cm3, depending on the family of ceramics. They are generally heavier than plastics but lighter than steels. Out of all the grades of advanced ceramics, boron carbide has the lowest density of 2.5 g/cm3, followed by sintered silicon nitride and carbide, and aluminium nitride with a density of just over 3.0 g/cm3. Alumina have densities between 3.6 and 3.9 g/cm3, while for zirconias, they reach 5.5 g/cm3 for magnesia-stabilised zirconia and approximately 6.0 g/cm3 for yttria-stabilised zirconia.
Application markets
Only the lightest advanced ceramics will be specifically used in industries where they provide a significant advantage as a result of this characteristic. In particular, it is worth noting that boron carbide is very popular in the military industry for shielding applications and silicon nitrides and carbides in the space industry for structural parts, reflectors, nozzles, etc.
Comparative table of properties
| Values at ambient temperature – 20°c |
Density (g/cm3) |
Resistance to compression (MPa) |
Resistance to bending (MPa) |
Young's modulus (GPa) |
Hardness (Vickers -GPa) |
Mechanical shock resistance (Tenacity) K(Ic) |
| Alumina (94 to 99.8 % ) | 3.6 to 3.9 | 1700 to 2500 | 250 to 350 | 350-370 | 12 to 18 | 4 to 5 |
| Alumina-zirconia composites | 4.0 | 2000 | 450 | 350 | 14 | 5 to 6 |
| Zirconia MgO | 5.5 | >1700 | 550 to 700 | 170 to 200 | 11 to 12 | 6 to 8.5 |
| Zirconia Y-TZP | 6.0 | 2000 to 2500 | 900 to 1250 | 200 to 220 | 12 to 16 | 10 to 13 |
| Aluminium nitride | 3.3 | 2000 | >300 | 310 | - | 3 |
| Silicon nitride | 3.2 | 2500 to 3000 | 650 to 900 | 300 to 315 | 15 to 16 | 7.5 to 8 |
| Silicon carbide | 3.1 | 2500 to 3900 | 400 to 550 | 410 | 24.5 to 28 | 4 to 4.6 |
| Boron carbide | 2.5 | >1500 | 425 | 440 | 28 | 3 to 4 |
Acceptable: + ; Good: ++ ; Very good: +++.
These values are for information only and do not constitute a contractual obligation.