Silica Aerogel
Silica aerogel is an oxide-based engineering ceramic. It has the lowest density among oxide-based engineering ceramics. In addition, it has the lowest tensile strength and the lowest thermal conductivity. The graph bars on the material properties cards below compare silica aerogel to other oxide-based engineering 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
Elastic (Young's, Tensile) Modulus
0.0050 GPa 0.00073 x 106 psi
Poisson's Ratio
0.2
Shear Modulus
0.0030 GPa 0.00044 x 106 psi
Tensile Strength: Ultimate (UTS)
0.016 MPa 0.0023 x 103 psi
Other Material Properties
Density
0.1 g/cm3 6.2 lb/ft3
Thermal Conductivity
0.016 W/m-K 0.0093 BTU/h-ft-°F
Thermal Expansion
2.0 µm/m-K
Common Calculations
Stiffness to Weight: Axial
0.028 points
Stiffness to Weight: Bending
57 points
Strength to Weight: Axial
0.044 points
Strength to Weight: Bending
1.4 points
Thermal Shock Resistance
110 points
Followup Questions
Further Reading
Aerogels Handbook, Michel A. Aegerter et al. (editors), 2011
Springer Handbook of Condensed Matter and Materials Data, W. Martienssen and H. Warlimont (editors), 2005