27 Aug 2009 Fused silica is a non-crystalline (glass) form of silicon dioxide. Its highly cross linked three dimensional structure gives rise to its high use temperature and low thermal expansion coefficient. Fused silica is a non-crystalline (glass) form of silicon dioxide (quartz, sand). Typical of glasses, it lacks long range order in its atomic structure. Its highly cross linked three dimensional structure gives rise to its high use temperature and low thermal expansion coefficient.
Key Properties
- Near zero thermal expansion
- Exceptionally good thermal shock resistance
- Very good chemical inertness
- Can be lapped and polished to fine finishes
- Low dielectric constant
- Low dielectric loss
- Good UV transparency
Mechanical
Specific gravity: 2.201 g/cm3
Poisson’s ratio: 0.17
Mosh hardness: 5.5-6
Knoop hardness: 880-1000 kg/mm2
Thermal
Thermal expansion coefficient: 5.4 x 10-7 (degree-1)
Optical
Nd: 1.45847
Nf – Nc: 0.00677
Vd: 67.70 | 
