The term mainly refers to a mix of lithium and aluminosilicates that yields an array of materials with interesting thermomechanical properties. The most commercially important of these have the distinction of being impervious to thermal shock. Thus, glass-ceramics have become extremely useful for countertop cooking. The negative thermal expansion coefficient (CTE) of the crystalline ceramic phase can be balanced with the positive CTE of the glassy phase. At a certain point (~70% crystalline) the glass-ceramic has a net CTE near zero. This type of glass-ceramic exhibits excellent mechanical properties and can sustain repeated and quick temperature changes up to 1000 °C. COUNT 5
QSN1 How high of a temperature change can glass-ceramics handle? ANS1 1000 °C QSN2 Because of their heat resistance, glass-ceramics are especially suitable for what? ANS2 countertop cooking QSN3 What is the most economically significant property of glass-ceramics? ANS3 impervious to thermal shock QSN4 What ingredients give glass-ceramics its useful heat tolerance? ANS4 lithium and aluminosilicates QSN5 What proportion of crystalline ceramics yields a product with a CTE of around 0? ANS5 ~70%