# 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 10 ^{6} psi*

Poisson's Ratio

0.2

Shear Modulus

0.0030 *GPa* 0.00044 *x 10 ^{6} psi*

Tensile Strength: Ultimate (UTS)

0.016 *MPa* 0.0023 *x 10 ^{3} psi*

## Other Material Properties

Density

0.1 *g/cm ^{3}* 6.2

*lb/ft*

^{3}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