Investigation on Microstructure, Mechanical, Biocorrosion and Biocompatibility Behavior of Nano-Sized Tio2Al2o3 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 synthesised using the precipitation reaction method with Ca(NO 3 ) 2 .4H 2 O as calcium and H 3 PO 4 as phosphorus sources. The alkaline pH was maintained with the addition of NH 4 OH dropwise to assist the hydrolysis. The as-received Al 2 O 3 was coated with TiO 2 via the sol-gel route and characterised via XRD, FE-SEM, and TEM with SAED analysis. The composite samples were cast in three compositions, pure Mg, Mg-HAp-Al 2 O 3 and Mg-HAp-TiO 2 @Al 2 O 3 . The microstructure, phase composition, mechanical as well as degradation performance (immersion and electrochemical tests, in PBS solution) were analysed. The chemical route of synthesising the HAp and TiO 2 @Al 2 O 3 powders resulted in uniform particle size. The addition of reinforcement particles in Mg enhanced the mechanical properties and reduced the 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 TiO 2 @Al 2 O 3