Adhesive properties of nanocoating modified by wire-brushing method

(Nanowerk News) Researchers from Amir Kabir University of Technology succeeded in the modification of adhesive and corrosive properties of hydroxyapatite nanocoatings by modifying the sub-layer through wire-brushing method (see paper in Ceramics International: "Modification of electrophoretically deposited nano-hydroxyapatite coatings by wire brushing on Ti–6Al–4V substrates").
This plan can be used directly or indirectly in medical engineering and biomaterials industries.
Hydroxyapatite coating on titanium sub-layer doesn't acquire the necessary adhesive strength in order to be used for medical purposes. The main problem is caused during the sintering of hydroxyapatite (HA). High temperature of sintering (higher than 1200 °C) erodes the sub-layer metal and also results in the decomposition of hydroxyapatite.
The most important objectives of the research were to modify the adhesive and corrosive properties of hydroxyapatite nanocoatings by improving Ti-6Al-4V sub-layers through wire-brushing method.
“Hydroxyapatite nanoparticles were synthesized in this research with particle average size of 65 nm through chemical deposition method," Hamid Reza Farnoush said, elaborating on the results of the research.
"Adhesive strength was calculated to be around 24 MPa for the electrophoretic coating of hydroxyapatite nanoparticles on the modified Ti-6Al-V sub-layer. The value was almost twice the value of the sample without brushing pre-preparation. Results obtained from the corrosion test on the coated sample on the brushed surface showed noticeable reduction in the corrosion current density and corrosion rate while they showed increase in the corrosion potential and polarization resistance.”
Source: INIC