Glass Ceramics & Composites

  SEM image of a glass ceramic Copyright: © GHI

Glass ceramics are used in many fields of application in our daily lives due to their highly adjustable material properties. Among other things, the coefficient of thermal expansion, the strength and the optical properties can be controlled by the formation of one or more crystalline phases. The properties of the glass-ceramic depend on the properties and the proportion of the crystalline phase in the glass-ceramic.



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Jonas Hildebrand

Glass ceramics & composites


+49 241 80 94976



Influence of cold plasma on glass ceramics

Corona discharges at several wire tips Copyright: © GHI Corona discharges at several wire tips over a glass sample. The glass rests on a grounded plate electrode.

The nucleation and crystallization behavior of glasses can be influenced and controlled in a variety of ways, for example by adding nucleating agents. However, external factors such as a defined furnace atmosphere or the application of an electric field during the ceramization process also have an effect on crystallization. Influencing glass properties by applying an electrical field at elevated temperatures (also known as thermal poling) can be done in various ways, for example by placing a glass between two capacitor plates. Another possibility is the so-called corona poling. Here, high electrical voltages of several thousand volts are applied to electrode tips and a corona discharge generates a plasma in the furnace chamber. Depending on the polarity of the applied voltage, negatively or positively charged ions are present, which cause different effects on the glass surface. Due to the open electrode configuration, there is also the possibility of interaction between glass and atmospheric components in the E-field. The effects of E-fields and different atmospheres on the structure and thereby changed mechanical properties of glass ceramics are to be investigated in an ongoing research project in order to be able to functionalize these materials specifically for their application.