The analysis of thermal and anodic oxide layers on selected biocompatible titanium alloys

Abstract

In the case of titanium alloys, the oxide layers on their surfaces strongly influence biocompatibility and corrosion resistance. To improve these characteristics, properties of oxide layers prepared by various methods on different base materials were examined. In this work, samples of widely used biomaterials, CP titanium grade 2 and alloy Ti6Al4V, were compared with recently developed β‐titanium alloy Ti‐39 wt% Nb. On the samples from these materials, the thermal (600°C/8 hr/atmospheric air) and anodic (1‐M H2SO4/100 V/1 hr) oxide layers were prepared. The change of surface color was observed. The surface topography of oxidized samples was observed using scanning electron microscopy. The thickness of oxide layers was measured and observed on the cross‐sectional samples. The further analysis of oxide layers surfaces was conducted using X‐ray photoelectron spectroscopy and atomic force microscopy. The growth of hydroxyapatite for further comparison of oxide layers was realized in Hank' balanced salt solution.

The cytocompatibility of anodized surfaces for implant materials

“…Vznik nanostruktury na povrchu titanových slitin pomocí anodické oxidace je v souladu s předcházejícími experimenty [13,14] a literaturou [9], kde byla obdobná struktura získána na čistém titanu (CP Ti grade 2). Změna drsnosti i zbarvení povrchu také odpovídá předpokladům dostupným z literatury [1,13].…”

“…Vliv vnitřní struktury se ovšem projevuje ve větší míře (viz výsledky termické i anodické oxidace na β titanové slitině [14]). Navíc u zkoumaných vzorků z Ti6Al4V ELI byl dodán atest od výrobce materiálu a struktura byla také kontrolována pomocí metalografické analýzy, kde nebyly nalezeny odchylky.…”

“…Zároveň je ovšem možné říci, že vyšší buněčná aktivita na oxidovaných vzorcích odpovídá výsledkům získaným na obdobných vzorcích z Ti6Al4V v práci [14] a CP Ti grade 2 v práci [15], kde byly vzorky ponořeny do Hanksova roztoku a byl sledován růst hydroxylapatitu.…”

Ti6Al4V foams having nanotubular surfaces for orthopaedic applications

“…To facilitate bioactivity, various surface treatment modalities were investigated for titanium alloys, including shot peening, hydrothermal treatment, and surface coating with hydroxyapatite . Among these techniques, a commonly used approach is anodization where oxide‐based nanotubular features could be fabricated on Ti6Al4V surfaces . Basically, anodization is the electrochemical oxidation of valve metals by providing an electrical field in certain electrolytes.…”

“…11 Among these techniques, a commonly used approach is anodization where oxide-based nanotubular features could be fabricated on Ti6Al4V surfaces. 12,13 Basically, anodization is the electrochemical oxidation of valve metals by providing an electrical field in certain electrolytes. When fluorinated electrolytes are used to anodize Ti6Al4V, oxide-based nanotubular arrays form on its surfaces.…”