Observation of Toughness Improvement of the Hydroxyapatite Bioceramics Densified Using High‐Frequency Induction Heat Sintering

Abstract

A novel nanocomposite has been introduced to improve the fracture toughness of hydroxyapatite (HAp) bioceramics. Composites of HAp/NiO with 1–5 wt% of electrospun NiO nanofibers were developed and studied. The mixtures were consolidated very rapidly to full density by high‐frequency induction heat sintering (HFIHS). The role of NiO nanofibers in enhancing the toughness, hardness, and microstructure properties of the HAp bioceramic was investigated. Field emission scanning electron microscopy was used to examine the morphology of the bioceramic composites and fracture surfaces to reveal the dominant toughening mechanisms. The results showed that the sintering behaviors, toughness, and hardness of the resulting composites were significantly enhanced by the inclusion of NiO nanofibers. The fracture toughness of the heat sintered HAp/NiO electrospun nanofiber composites was 1.8 times higher, as the concentration of NiO electrospun nanofibers reached 5 wt%.