Synthesis characterization and mechanical behaviour of haznofe3o4 composites for implant applications

Abstract

newline The high biocompatibility of Hydroxyapatite (HA) makes it one of the most common ceramics used in bioimplants. However, its inferior mechanical properties can be improved through the formation of composites. HA-based biocompatible and bioactive composite is an appropriate choice for bio-implants. In the present work, HA was first synthesized using the wet chemical precipitation method and then its composites were fabricated by adding micron and nano-sized Zinc Oxide (ZnO) and Iron oxide (Fe3O4) in HA through conventional sintering to form micro composites and nanocomposites respectively. ZnO ratio was kept fixed at 7.5% while Fe3O4 was taken in 3 ratios of 10%, 20%, and 30%. Further, a nanocomposite with HA-ZnO-10wt%Fe3O4 composition was also fabricated using Spark plasma sintering to study the effect of the change of the sintering method. newlineMicrostructural characterization was done for the composites using Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). Density was measured using Archimedes s principle. The mechanical properties and tribological properties were studied using a micro-hardness test, compression test, and fretting wear test respectively while antibacterial properties were investigated using the disc diffusion method. newlineThe microstructural examination showed the effect of the addition of Fe3O4 on the interface formation, which is exhibited by interconnected pores and sintered necks in the micrographs. The experimental results showed that the addition of micron-sized 7.5% ZnO in HA has resulted in an improvement of relative density to around 99%, increased hardness ( and#820; 6.9 GPa) but with reduced compressive strength ( and#820; 25.6 MPa) making it suitable for hard coatings over implants. The addition of 10 wt % of nano-sized Fe3O4 in HA has resulted in higher hardness ( and#820; 7 GPa) with a much lower wear rate ( and#820; 0.96 mm3/Nm) in comparison to pure HA. This composition s micro composites have also resulted in the highest antibacterial prop