Abstract
The aim of this work is to develop novel functional ceramics by Spark Plasma Sintering (SPS) of powders composed by metastable amorphous phases. An amorphous Alumina/Silica (molar ratio 1:1) powder obtained by rapid quenching of the melt was sintered by SPS and compared to the pressureless sintering method results. Unique amorphous bulks with promising functionality are expected. It was found that although the amorphous phase could be maintained by SPS at 850degC (100degC/min, 0sec), the relative density was low (80%). The densification proceeded (95%) at 900degC but abrupt mullite crystallization leaded to cracking. However, since densification did not proceed (50%) by pressureless sintering at 900-1100degC, the present process was found to be a potential method to produce unique amorphous bulks and improve sinterability.
