Robax Glass Ceramic

Robax is a transparent glass ceramic of a slight amber shade made on the basis of the glass ceramic system Li20-Al203-Si02. 

The very low coefficient of linear thermal expansion, the extremely high maximum service temperature, and excellent thermal shock resistance are outstanding characteristics of Robax glass ceramic. 

Consequently, this material is suited for applications in which other glasses - including borosilicate glass (Tempax , Borofloat , Pyrex ) - fail to qualify for use within some components, due to too elevated temperatures and too heavy temperature shocks and temperature gradients. In such application fields Robax frequently proves to be a suitable alternative to quartz glass. 

The low density and the inherent stability, as well as the maximum service temperature are characteristics that make this glass ceramic an interesting design material. In many ambients, the material is chemically resistant. Since - because of the extremely low thermal expansion - mechanical stresses occur-ing in the material and attributable to changes of temperatures are negligible, the material does not fatigue due to these stresses. 

As compared with metallic or polymeric materials, the disadvantage of the material is to be explained by its vitreous nature . Brittleness and high notch impact strength are of great significance to the user as they make the component s load capacity heavily dependent on the component s surface condition. 

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Robax glass-ceramic is the nonpigmented version of Ceran glass-ceramic. Its properties are summarized in Table 4-11 (Robax 1998). 

The compositions of P-quartz solid solution glass-ceramics produced on a large scale for technical applications are summarized in Table 2-7. These glass-ceramics are called Vision , Zerodur , Narumi , Neoceram , Ceran , and Keraglas . Other products are Robax , which represents a col-... 

Properties of B-Spodumene Solid-Solution Glass-Ceramic Neoceram N-11 and the B-Quartz Solid-Solution Glass-Ceramics Neoceram N-0, Ceran , and Robax ... 

Transparent and Tinted Glass Ceramics Table 3.5. Comparison of some Robax and borosilicate glass Tempax properties ... 

Its characteristics render Robax virtually a material predestined for the user as sight panels capable of sustaining high temperatures. Thus, this glass ceramic is used for sight and protective panels in combustion furnaces (e.g., for wood, coal, oil, gas), industrial furnaces, and electrically powered furnaces, and for cover panels in front of open fireplaces . 

Today, flat glass ceramic panels are available in practically all sizes to be used for ovens and fireplaces. Moreover, curved and formed Robax panels... 

The properties of other glass ceramic products have also been tailored to special household applications the properties of the glass ceramic Robax were adapted to its use as stove windows. Chemical strengthening of the surface of another glass ceramic used for cooktops can improve their functionality. 

The transparent glass ceramic from Schott, called Robax , has a slight amber shade and its rolled surface exhibits a slight texture from the manufacturing process. 

The low density and the inherent stability, the high thermal load and the good transparency are characteristics that make this glass ceramic an interesting design material. In many environments, Robax is chemically resistant. 

Fig. 2.22. Variation of the viscosity of Robax base glass during ceramization with a heating rate of 5 K/min...

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