Fabrication Of HA/Fe₂O₃ Composite Materials And Their Bioactivity In Vitro

Hydroxyapatite(HA)is a highly biocompatible material,which possesses the ability to improve osseointegration.However,poor mechanical properties of HA,such as low strength and high brittleness,make the HA material can not meet the requirements of load,thus limiting its effective application,In order to solve this problem,HA coating with metal substrate composite was focused on by most of researchers,so as to achieve the required mechanical strength and biological activity of bioceramic composite materials.In order to obtain better bioactivity and mechanical strength as well as HA composite coatings with certain bacteriostasis,via adding a kind of osteogenic trace element compound Fe2O3 and then adding another compound SiO2,SrCO3,Al2O3,Al(OH)3,then HA/Fe2O3/SrCO3,HA/Fe2O3/Al2O3 and HA/Fe2O3/Al2O3-h composite coatings were prepared by electrophoretic deposition and subsequentially sintering respectively.The physical and chemical properties of the HA composite coatings were tested and characterized by SEM,FT-IR,universal testing machine,EDS,XRD and electrochemical workstation.Meanwhile,the antibacterial property of the HA composite coating and evaluated the bioactivity of the composite coating in HEPES simulated body fluids was studyed.The experimental results show that HA/Fe2O3/SiO2,HA/Fe2O3/SrCO3,HA/Fe2O3/Al2O3,HA/Fe2O3/Al2O3-h composite coatings with Ti substrate have excellent bonding strength up to 31.9 MPa,29.9 MPa,33.7 MPa and 31.8 MPa,respectively.These composite coatings possessed better corrosion resistance in the self-constructed HEPES simulated body fluids(H-SBF)and the corresponding composite coating powders was being some antibacterial properties,average inhibition zone and the inhibition rates were 10.5 mm and 81.9%,10.2 mm and 80.0%,9.6 mm and 75.0%,10.1 mm and 77.5%,respectively.These composite coatings exhibited well bioactivity in H-SBF.The HA/Fe2O3/SiO2 composite coating is the most comprehensive features,so the HA/Fe2O3/SiO2 composite coating is expected to be developed into a new generation of bone substitute implant material.