The effect of alumina contamination from the ball-milling of fused silica on the high temperature properties of injection moulded silica ceramic components

The amount of alumina contamination present in ball-milled silica powders has been shown to increase with increased mill time for materials manufactured during the same time period. This alumina contamination level has also been observed to vary depending on the date, and possibly the state of repair, of the ball mill itself. The associated alumina level has been shown to significantly influence the high temperature properties (at 1475 °C) of the materials, with high contamination levels not only resulting in increased flexural strength and creep resistance, but also increasing the thermal contraction of the materials when dilatometer measurements were performed to 1600 °C.