In this work, a precursor of HA, ca

In this work, a precursor of HA, calcium hydrogen phosphate dihydrate (CaHPO4⋅2H2O, termed as DCPD), was used to assist the densification of HA. DCPD can convert to HA under alkaline conditions, and decompose above 100 ◦C to calcium hydrogen phosphate (CaHPO4, termed as DCPA), which is also a precursor of HA. As the precursors provide nucleation sites for HA, they may form hydrogen bonds [7,8]. Also, both DCPD and DPCA are biomaterials, and they degrade faster than HA in body fluids. Their combination can compensate for the slow degradation rate of HA [9]. However, due to the thermal instability of DCPD and DCPA, which will decompose at temperatures over 400 ◦C during conventional sintering [10], no dense HA/DCPD or HA/DCPA composites have been reported so far. The low-temperature processing nature of CSP is presumably suitable for the sintering of temperature-sensitive ceramics and their composites. Therefore, in this work, we prepared dense HA/DCPA composites via CSP for the first time and investigated the effect of the initial DCPD content on the densification of HA and mechanical properties of the composites.