Composite Ceramics Based on NaCaPO4 and Na4Ca4Si6O18

The development of resorbable composite ceramics based on the Na2O–CaO–SiO2–P2O5 system is complicated by sensitivity of the phase composition to the initial component ratio and heat treatment conditions, which can subsequently lead to variability of the functional properties of the final product. The composite ceramics obtained in the present study from a powder mixture of tricalcium phosphate Ca3(PO4)2 and sodium metasilicate pentahydrate Na2SiO3·5H2O (molar ratio 4 : 6) and fired in the temperature range of 800–1100°C had the target phase composition comprising β-rhenanite β-NaCaPO4 and sodium calcium silicate Na4Ca4Si6O18. It was shown that low-temperature ceramics with a compressive strength of up to 19 MPa and porosity of up to 55% can be manufactured using heat treatment temperature of 500°C. A temperature rise up to 1100°C caused a twofold increase in the compressive strength accompanied by a 10% decrease in the porosity. The ceramic materials produced in the Na2O–CaO–SiO2–P2O5 system can be recommended as resorbable porous materials for the treatment of bone tissue defects.