Study on liquid phase sintering of calcium phosphate

Abstract

In this paper, a novel method was reported to prepare dense hydroxyapatite (HA)/β-tricalcium phosphate (β-TCP) and pure β-TCP ceramics at sintering temperatures lower than the normal ones for calcium phosphate ceramics. A simple sol-gel process was firstly engaged to synthesise a sol with a Ca/P molar ratio of 0·56 (Ca_0·56P) and then it was introduced into pure HA powders not only to be used to create liquid phase to enhance densification but also to allow it to react with HA to form biphasic HA/β-TCP ceramics during sintering. The effect of the content of Ca_0·56P on biphasic β-TCP/HA components and densification during the sintering process was investigated. The resulting samples were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and density measurement using the Archimedes’ method. This study provides a simple and cheap approach to synthesise biphasic HA/β-TCP and pure β-TCP ceramics.