Fused silica is a light material. Its density is 2.202g/cm3.
To a small amount the density is influenced by the annealing conditions of the glass near the transformation temperature.
By comparison the density of the aluminum is approximately 2.6 g/cm3, and that of Invar is 8.1 g/cm3.
Elasticity Modulus
Fused silica shows an almost perfect brittle-elastic behavior at temperatures lower than the transformation point.
Fused silica elasticity modulus is 73 GPa at 25șC.
By comparison, steel has a Young's Modulus of the order of 205 GPa
Effect of Surface Flaws on Mechanical Properties
Fused silica is extremely strong in compression, with design compressive strength of better than 1.1 x 109 Pa.
Under tension, the story is more complicated. Surface flaws can drastically reduce the inherent strength of any glass; so tensile properties are greatly influenced by these defects and by the manufacturing processes used to create the desired fused silica object.
To date the common practice has been to use a design tensile strength for fused silica with 'good' surface quality, taking into consideration safety margin and fatigue, of 5-7 x 106 Pa.
The Translume manufacturing processes are extremely gentle and create virtually no microcracks. Preliminary data indicates that when using Translume manufactured devices a design tensile strength superior to 108 Pa can be safely assumed.
