Toughening of glass

Toughening of glass is most frequently used with sheet glass intended for vehicle wind screens, building items (e.g. all-glass doors) etc. Toughening is also employed in the manufacture of domestic glass-ware, spectacle lenses, instrument parts, etc. 

FIGURE 9. A composite approach for strengthening and toughening of glass by metallic inclusions [137]. 

To balance some of the drawbacks produced by the rubber toughening of thermosets, inorganic fillers that increase modulus and yield stress can be added to generate hybrid composites. Inorganic fillers such as glass beads, alumina, or silica - with high values of modulus and strength - are frequently included in thermoset formulations. 

Tempered glass plates are made from heat toughened plate glass. They may be purchased (see list of suppliers) or constructed in a glass workshop. 

Residual stresses are generally deleterious to the mechanical properties and should be avoided. This is especially true if a part is to be subjected to thermal cycling. In some situations, however, residual stresses can be used to advantage. A case in point is the transformation toughening of zirconia discussed in Chap. 11, and another excellent example is the tempering of glass discussed in the next section. 

Pietl, E.D. Zanotto, Thermal shock properties of chemically toughened borosilicate glass, J. Non-Cryst. Solids, 247, 39 (1999). 

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