BigPatents India

The present invention relates to a process of making ultra low expansion glass ceramics. The glass ceramic material finds use in electronic devices, heat engine components, spark plug or as hot plate tops, domestic cooking ware and other such applications where zero to a moderate thermal expansion coefficients and higher mechanical strength are required. The novelty of the present invention lies in making ultra low expansion glass ceramics with low glass melting temperature, broader working range. Moreover the expansion coefficients obtained was very low of the order of 3-12 X 10-70C between the temperature range room temperature to 5000C. This has been achieved by forming a glass batch using a combination of ground blast furnace slag and china clay and a moderator in the form of boric acid.