Alumina vs. Alpha Quartz
Alumina belongs to the oxide-based engineering ceramics classification, while alpha quartz belongs to the non-glass optical ceramics. There are 11 material properties with values for both materials. Properties with values for just one material (18, in this case) are not shown.
For each property being compared, the top bar is alumina and the bottom bar is alpha quartz.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 220 to 370 | |
| 91 |
| Knoop Hardness | 960 to 1660 | |
| 740 |
| Poisson's Ratio | 0.22 to 0.24 | |
| 0.13 |
Thermal Properties
| Melting Onset (Solidus), °C | 2040 | |
| 1590 |
| Specific Heat Capacity, J/kg-K | 870 to 940 | |
| 720 |
| Thermal Conductivity, W/m-K | 14 to 30 | |
| 8.5 |
| Thermal Expansion, µm/m-K | 6.7 to 8.2 | |
| 9.5 |
Otherwise Unclassified Properties
| Density, g/cm3 | 3.4 to 4.1 | |
| 2.7 |
Common Calculations
| Stiffness to Weight: Axial, points | 35 to 53 | |
| 19 |
| Stiffness to Weight: Bending, points | 57 to 62 | |
| 57 |
| Thermal Diffusivity, mm2/s | 3.7 to 10 | |
| 4.4 |