Fabrication of Dense Hydroxyapatite Nanobioceramics with Enhanced Mechanical Properties via Two‐Step Sintering Process

Fully dense hydroxyapatite (HAp) nanobioceramics with enhanced mechanical properties were fabricated via two‐step sintering (TSS) process. The effects of sintering parameters on the microstructures and mechanical properties of HAp bioceramics were investigated. The results showed that the grain growth could be effectively suppressed via TSS and the grain size was 193 nm for the samples with 99.02% relative density. Comparing with conventional sintering process, the hardness (4.86 GPa) and fracture toughness (1.18 MPa m 1/2 ) of the dense samples fabricated by TSS were increased about 12% and 57%, respectively. Therefore, TSS provided a facile method to fabricate fully dense HAp nanobioceramics with enhanced mechanical properties.