A crystalline or vitreous-crystalline devitrified glass having a negative or very low and positive thermal expansion coefficient

摘要

A ceramic glass material has a coefficient of thermal expansion which is either negative or very low and positive and consists predominantly, in a proportion of at least 50% by weight, of beta-eucryptite as devitrification product. Examples of suitable compositions of SiO2, Al2O3 and Li2O are given, which include also TiO2 and MgO. TiO2 can be present up to 10% and MgO up to 8%. B2O3 may also be present up to 8%.