Synthesis and densification of hydroxyapatite by mechanochemically-activated reactive cold sintering

Abstract

We proposed a reactive cold sintering method based on the activation of reactants by ball-milling. Using CaHPO4⋅2H2O and Ca(OH)2 as precursors after mechanical activation for different times, the simultaneous synthesis and densification of hydroxyapatite (HA) products were achieved by cold sintering at temperatures ranging from 50 to 200 °C. The effects of processing parameters including milling time, temperature, uniaxial pressure and holding time on the synthesis and densification behavior of HA were systematically investigated and the underlying mechanisms were addressed. This study provides a simple, feasible and scalable route for the rapid low-temperature synthesis and densification of HA and its composites.