Thermal Expansion of Fused Quartz Powder Compacts

The fused quartz is one of the most typical materials of low thermal expansion. However, it was found that compacts prepared by isostatic compression of ground powder of fused quartz showed an anomalously high thermal expansion of 7×10-6/°C, i.e., about 10 times of that of the normal fused quartz. The density of the glass powder increased with grinding time and with increasing pressure of compaction. Release of the compaction strain by heating can be the reason of this high thermal expansion of the compacts of fused quartz powder.