7075 Aluminum vs. Optical Silicon
7075 aluminum and optical silicon belong to fundamentally different material chemistries. 7075 aluminum is a metal, while optical silicon is a ceramic material. 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 (22, in this case) are not shown.
For each property being compared, the top bar is 7075 aluminum and the bottom bar is optical silicon.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 70 | |
| 150 |
| Poisson's Ratio | 0.32 | |
| 0.28 |
| Shear Modulus, GPa | 26 | |
| 80 |
| Tensile Strength: Ultimate (UTS), MPa | 240 to 590 | |
| 110 |
Thermal Properties
| Maximum Temperature: Mechanical, °C | 200 | |
| 1350 |
| Melting Onset (Solidus), °C | 480 | |
| 1560 |
| Specific Heat Capacity, J/kg-K | 870 | |
| 700 |
| Thermal Conductivity, W/m-K | 130 | |
| 150 |
| Thermal Expansion, µm/m-K | 23 | |
| 3.0 |
Otherwise Unclassified Properties
| Density, g/cm3 | 3.0 | |
| 2.3 |
Common Calculations
| Stiffness to Weight: Axial, points | 13 | |
| 35 |
| Stiffness to Weight: Bending, points | 46 | |
| 75 |
| Strength to Weight: Axial, points | 22 to 54 | |
| 13 |
| Strength to Weight: Bending, points | 28 to 52 | |
| 22 |
| Thermal Diffusivity, mm2/s | 50 | |
| 93 |
| Thermal Shock Resistance, points | 10 to 25 | |
| 18 |