Porous Ceramic Based on Calcium Pyrophosphate

Abstract

Porous ceramic, whose composition is mainly represented by calcium b-pyrophosphate b-Ca 2 P 2 O 7 , is prepared from a porous mixture containing synthetic calcium g-pyrophosphate g-Ca 2 P 2 O 7 and milled 1-aqueous sodium dihydrophosphate in an amount from 2.5 to 40 wt.%. Ceramic sintering proceeds by a liquid-phase sintering mechanism due to melt formation in the system Na 2 O-CaO-P 2 O 5 . Ceramic microstructure after firing in the range 800 -1000°C makes it possible to consider sodium polyphosphate not only as a component facilitating sintering by a liquid-phase mechanism, but also as an inorganic pore-forming agent.