Strengthening of silica glass by gel-derived coatings

Mechanical behavior of glass reinforced with SiO2 hybrid sol–gel coatings

“…Both tests were analyzed using the Weibull procedures. The Weibull analysis [2], is based on the Ôweakest link theoryÕ of Pierce [6], has been widely used for modeling the inherent scatter of the brittle material strength. Pierce carried out some research on the development of reliable procedures for the testing of yarn and stated that ÔIt is a truism, of which the mathematical implications are of no little interest, that the strength of a chain is that of the weakest linkÕ.…”

“…Several attempts have been made with the application of sol-gel derived SiO 2 , SiO 2 -ZrO 2 and multi-component glass coatings [6][7][8]. Although these experiments led to increasing the bending strength of glass specimens, such inorganic coatings are not suitable for the protection of the glass surface against mechanical load.…”

Performance and durability of octadecyltrichlorosilane coated borosilicate glass

“…In spite of the known benefits, the underlying mechanistic bases for the strength enhancement in the glass are unclear. Fabes and colleagues explored the efficacy of hydrolized tetraethylorthosilicate (TEOS) coated silica glass rods in laboratory air [12]. When the rods were abraded, coated with layers from 200 to 1000 nm in thickness, and annealed at temperatures from 400 to 900°C the mean strength measured in four-point flexure was increased from $100 to as high as 150 MPa.…”

Crack bridging mechanism for glass strengthening by organosilane water-based coatings

“…Various techniques have been developed to strengthen glass: etching which blunts the crack tip and reduces the stress singularity, thermal tempering [3][4][5] and ion exchange [6] which induce surface compression and so reduce the stress ÔfeltÕ by the crack. A third type of strengthening which is cheaper and easier to apply is obtained with coatings: sol-gel derived coatings [7][8][9] and polymeric coatings [10][11][12][13][14] have received attention. Hypotheses generally presented in these works to explain the reinforcement in addition to tip blunting and surface compression are energy dissipation at the crack tip for polymers, protection against water assisted corrosion and crack healing.…”