Effect of Al~(3+) Additions on the Properties of Quartz Ceramics

摘要

Quartz ceramic has a great potential use in engineering ceramic materials. However, due to the cristobalite transformation in sintering process, the mechanical properties are weakened. The influence of Al~(3+) additions on bending strength and open porosity of quartz ceramics was studied by adding Al_2O_3 and aluminum sulfate solution . The content of Al~(3+) ranged from 1% to 7%. Both samples were sintered at 1200°C for 2h. The bulk density of samples was measured by Archimede's displacement method and the flexural strength of the specimens was tested using a conventional three point flexural method. The addition of 3% Al~(3+) of aluminum sulfate leads to better properties (bending strength at 14MPa and open porosity at 23%). Glass theory was applied to explain the mechanisms of inhibiting crystallization of Al~(3+) additions.