## Tuesday, August 25, 2009

Inorganic glasses are one of the strongest known materials.

### Strength of Inorganic Glasses

The intrinsic inert strength of oxide glasses is among the highest of any known materials:
silica ~ 14 GPa
'window glass' - soda lime silica ~ 10 GPa.

The above is not commonly known or appreciated.
What is commonly known is that the 'practical', or commonly encountered strength of both of these glasses is ~ 50-70 MPa.

On the other hand, the now well-known lightguide fibers being installed in local telephone networks, does have and extremely high strength: ~5.5 GPa over MOST of its length.

It is clear that the reason for this enormous 'discrepancy' is that at some point, the glass surface has been 'mechanically damaged'.