Mullite vs. PEEK
Mullite and PEEK belong to fundamentally different material chemistries. Mullite is a ceramic material, while PEEK is polymeric. Therefore, their performance will be even more dissimilar than would be suggested by the difference in properties. There are 16 material properties with values for both materials. Properties with values for just one material (21, in this case) are not shown. Please note that the two materials have significantly dissimilar densities. This means that additional care is required when interpreting the data, because some material properties are based on units of mass, while others are based on units of area or volume.
For each property being compared, the top bar is mullite and the bottom bar is PEEK.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 800 | |
| 120 to 300 |
| Elastic (Young's, Tensile) Modulus, GPa | 110 to 170 | |
| 4.0 to 24 |
| Flexural Strength, MPa | 130 to 160 | |
| 150 to 330 |
| Tensile Strength: Ultimate (UTS), MPa | 160 | |
| 97 to 200 |
Thermal Properties
| Maximum Temperature: Mechanical, °C | 1680 | |
| 330 |
| Specific Heat Capacity, J/kg-K | 950 | |
| 1390 to 1700 |
| Thermal Conductivity, W/m-K | 3.5 to 11 | |
| 0.25 to 0.93 |
| Thermal Expansion, µm/m-K | 5.8 | |
| 15 to 52 |
Electrical Properties
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 10 to 11 | |
| 3.0 to 14 |
Otherwise Unclassified Properties
| Density, g/cm3 | 2.7 to 3.0 | |
| 1.3 to 1.5 |
Common Calculations
| Stiffness to Weight: Axial, points | 22 to 31 | |
| 1.5 to 10 |
| Stiffness to Weight: Bending, points | 58 to 62 | |
| 36 to 73 |
| Strength to Weight: Axial, points | 15 to 17 | |
| 20 to 41 |
| Strength to Weight: Bending, points | 22 to 24 | |
| 36 to 55 |
| Thermal Diffusivity, mm2/s | 1.4 to 3.7 | |
| 0.1 to 0.51 |
| Thermal Shock Resistance, points | 12 to 19 | |
| 34 to 57 |