Electrodeposition of fluorohydroxyapatite gradient coating on titanium alloy

Abstract

In order to obtain the apatite implants which can meet the requirements for both bonding strength and bioactivity, the FHA(Ca10(PO4)6OH2−xFx(x = 0 ~ 2)) gradient coating was prepared by electrophoretic deposition on the surface of titanium alloy (Ti–6Al–4V). The effects of fluorine substitution and gradient structure on the morphology, bonding strength, and bioactivity of the coating were investigated. The gradient coating has the dense inner layer and porous outer layer that were deposited by controlling the suspension concentration and the preparation process. Through controlling of the fluorine substitution gradient, the thermal expansion coefficient gradually changed to improve the bonding strength more than 30 Mpa. The inner layer with high fluorine content can improve the thermal stability of the coating and bonding strength between the coating and the substrate, while the proper content of fluorine in the outer layer improves the bioactivity of the gradient coating.

Preparation and physical‐biological characterization on titanium doped fluorophosphate nanobioglass: Bone implants

“…The elemental composition profile from EDS indicates the presence of P, Ca, Na, F, and O and their respective concentrations were expressed in atomic and weight %. The postimmersed bioglasses sample SEM results showed rough surface and the EDAX revealed the formation of hydroxyapatite and fluorapatite crystals 26 . When the Ca/P ratio is less than 1.3, the material is found to be highly soluble whereas when this ratio is greater than 1.3, solubility decreases.…”

“…The post immersed bioglasses sample SEM results showed rough surface and the EDAX revealed the formation of hydroxyapatite and fluorapatite crystals. 26 When the Ca/P ratio is less than 1.3, the material is found to be highly soluble whereas when this ratio is greater than 1.3, solubility decreases. Before invitro test, the calcium to phosphate ratio is 0.33 whereas after immersion the ratio reached a value of 1.67 which is an indication of the difference in solubility of the material .…”

High temperature oxidation behaviour of mono-layer and bi-layer coatings

“…Titanium alloy is widely used in the industrial, especially in aviation and medical fields, because of its excellent properties [1][2][3]. However, poor high temperature oxidation resistance of titanium alloy hinders its application in related fields [4,5].…”

Synthesis of high surface area nanostructured La2Zr2O7 by thermal decomposition of new ion pair complex precursor

“…The selection of thermal barrier coating materi-als is restricted by some parameters such as: 1) High melting point, 2) low thermal conductivity, 3) high sintering resistance, 4) high stability and ability to accommodate defects, 5) similar thermal expansion match with the metallic substrate. The RE 2 Zr 2 O 7 as pyrochlore compounds (RE = lanthanum, neodymium, europium and yttrium) were the subject of significant research because these compounds have structural stability, improved sintering resistance and lower thermal conductivity than yttria-stabilized zirconia as fluorite compounds [5,6]. The crystal structure of lanthanum zirconate is unique, and allows for numerous ionic substitutions at various lattice points, producing a large number of compounds with different thermal properties [7].…”