Fabrication and characterization of Mn-doped 45S5 bioglass coatings for Ti6Al4V implants

Abstract

Ti6Al4V shows promise as bone implants due to its strong mechanical properties. Coating Ti6Al4V can change the properties of Ti6Al4V, such as corrosion resistance and bioactivity. Bioactive coatings such as 45S5 bioglass are utilized to enhance corrosion resistance and bioactivity for metal substrates. This study investigates the effects of incorporating 1 % manganese into 45S5 bioglass, substituting calcium, and applying it as a coating on Ti6Al4V alloy. Some of the properties of the Mn-doped bioglass coating are compared with those of Ti6Al4V coated with standard 45S5 bioglass and with uncoated Ti6Al4V. The 45S5 bioglass (BG) and Mn-modified 45S5 bioglass (MBG) were synthesized using the sol-gel method. The coatings were applied to Ti6Al4V using dip coating after anodizing Ti6Al4V in H₂SO₄ acid. BG powders and coated specimens were subjected to a series of analyses, including FTIR, SEM, EDS, XRD, ICP, wettability and corrosion behavior tests. The results showed that the addition of manganese changed the color and crystallization of the 45S5 bioglass, leading to improved bioactivity. Both types of coatings increased wettability by approximately 80 % and reduced aluminum ion release by 66 %. Between the two coated samples, the MBG exhibited around 11 % less vanadium release compared to the BG sample. Polarization tests demonstrated that coating effectively decreased the thermodynamic tendency toward corrosion for both coated samples. Additionally, EIS results showed corrosion resistance values of 2.3 MΩ, 3.1 MΩ and 606 kΩ for the uncoated sample, the BG-coated sample, and the MBG-coated sample, respectively.