Glassy inorganic materials

The term ceramics refers to a broad range of materials including not only polycrystalline materials, but also powdered materials, thin films and single crystals, and glassy inorganic materials. In this section, we will use a slightly narrower definition of ceramics as polycrystalline sintered materials. 

As has been shown in this short review of the basis and applications of the TEM/HREM methods for ceramics and glassy materials investigation, the capability of this electron microscopy method for extracting valuable information from inorganic materials and their derived products has been widely demon-... 

It will be evident that whilst polymers are able to form glasses they are not unique and that the basic characteristics of the glassy state are common to a number of organic and inorganic materials. Some materials, such as ortho-terphenyl, form a glass if cooled quickly and subsequently change to a crystalline form. ... 

The phenomenon of crazing has been observed in many glassy polymers, and also in some crystalline polymers, when subjected to tensile stress. Polymer crazes (Fig. 9.8a) in their appearance are similar to the very fine cracks known for a long time to occur on the surfaces of inorganic materials such as ceramics. However, there is a difference between the crazes and the cracks in that crazes have a continuity of material across the craze plane (Figs. 9.8b, 9.9—9.11) whereas cracks do not possess any continuity. Consequently crazed zones are capable of bearing loads as opposed to cracked ones. 

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