Investigation on microstructure, mechanical, biocorrosion and biocompatibility behavior of nano-sized TiO2@Al2O3 reinforced Mg-HAp composites

The present work takes the benefit of employing a composite approach by reinforcing the pure Mg with bioinert and bioactive ceramic powders for strengthening and reducing their degradation inside the human body to make it a suitable candidate for orthopaedic implants. Hydroxyapatite (HAp) was selected as the bioactive material (a major constituent of the human bone). HAp was synthesized using the precipitation reaction method with Ca(NO3)(2).4H(2)O as calcium and H3PO4 as phosphorus sources. The alkaline pH was maintained with the addition of NH4OH dropwise to assist the hydrolysis. The as-received Al2O3 was coated with TiO2 via the sol-gel route and characterised via X-ray diffraction, scanning electron microscopy, and transmission electron microscopy with selected area diffraction analysis. The samples were cast in three compositions, pure Mg, Mg-HAp-Al2O3 and Mg-HAp-TiO2@Al2O3 . The microstructure, phase composition, mechanical and degradation performance (immersion and electrochemical tests) were analysed. The chemical route of synthesising the HAp and TiO2@Al2O3 powders resulted in uniform particle size. The addition of reinforcement particles in Mg enhanced mechanical properties and reduced corrosion rate. The cell viability of fabricated composites was observed above 80% at 20%, and 10% of extract solution and a noticeable improvement was observed with the employment of TiO2@Al2O3 . (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

This study employs a composite approach by reinforcing pure Mg with bioinert and bioactive ceramic powders to enhance its strength and reduce degradation inside the human body, making it a potential material for orthopaedic implants. The addition of reinforcement particles improves the mechanical properties and reduces the corrosion rate of Mg composites.