Fused Silica (Fused Quartz)
Fused silica is a glass-type material. It has a fairly low density among the glass and glass-ceramics in the database.
The properties of fused silica include two common variations. This page shows summary ranges across both of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare fused silica to other glass and glass-ceramics (top) and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Compressive (Crushing) Strength
1100 MPa 160 x 103 psi
Elastic (Young's, Tensile) Modulus
73 GPa 11 x 106 psi
Flexural Strength
67 MPa 9.7 x 103 psi
Knoop Hardness
570
Poisson's Ratio
0.17
Shear Modulus
31 GPa 4.5 x 106 psi
Tensile Strength: Ultimate (UTS)
50 MPa 7.2 x 103 psi
Thermal Properties
Maximum Temperature: Decomposition
1100 °C 2010 °F
Maximum Temperature: Mechanical
1080 °C 1980 °F
Melting Onset (Solidus)
1900 °C 3450 °F
Specific Heat Capacity
720 J/kg-K 0.17 BTU/lb-°F
Thermal Conductivity
1.4 W/m-K 0.79 BTU/h-ft-°F
Thermal Expansion
0.5 µm/m-K
Electrical Properties
Dielectric Constant (Relative Permittivity) At 1 MHz
3.8
Dielectric Strength (Breakdown Potential)
30 kV/mm 1.2 V/mil
Electrical Dissipation At 1 MHz
0.00011
Electrical Resistivity Order of Magnitude
14 10x Ω-m
Otherwise Unclassified Properties
Density
2.2 g/cm3 140 lb/ft3
Light Transmission Range
0.16 to 3.5 µm
Refractive Index
1.5
Common Calculations
Stiffness to Weight: Axial
18 points
Stiffness to Weight: Bending
63 points
Strength to Weight: Axial
6.3 points
Strength to Weight: Bending
14 points
Thermal Diffusivity
0.85 mm2/s
Thermal Shock Resistance
97 points
Followup Questions
Further Reading
Ceramic and Glass Materials: Structure, Properties and Processing, James F. Shackelford and Robert H. Doremus (editors), 2008
Glass: Mechanics and Technology, Eric Le Bourhis, 2007
Handbook of Optical Materials, Marvin J. Weber, 2003
Handbook of Optical Constants of Solids, Edward D. Palik (editor), 1998
Ceramics and Composites: Processing Methods, Narottam P. Bansal and Aldo R. Boccaccini (editors), 2012