Comparison of Ti–35Nb–7Zr–5Ta and Ti–6Al–4V hydrofluoric acid/magnesium-doped surfaces obtained by anodizing

Abstract

Objectives Development of a new generation of stable β alloy, free of aluminum or vanadium and with better biological and mechanical compatibility and evaluate the surface properties of Ti–6Al–4V and Ti–35Nb–7Zr–5Ta after anodization in hydrofluoric acid, followed by deposition of different electrolyte concentrations of magnesium particles by micro arc-oxidation treatment. Methods Disks were anodized in hydrofluoric acid. After this first anodization, the specimens received the deposition of magnesium using different concentration (8.5% and 12.5%) and times (30s and 60s). The surface morphology was assessed using scanning electron microscopy, and the chemical composition was assessed using energy dispersive x ray spectroscopy. The surface free energy was measured from the contact angle, and the mean roughness was measured using a digital profilometer. Results Anodization in hydrofluoric acid provided the formation of nanotubes in both alloys, and the best concentration of magnesium considered was 8.5%, as it was the condition where the magnesium was incorporated without covering the morphology of the nanotubes. X-ray dispersive energy spectroscopy showed magnesium incorporation in all conditions. The average roughness was increased in the Ti–35Nb–7Zr–5Ta alloy. Conclusions It was concluded that anodizing could be used to deposit magnesium on the surfaces of Ti–6Al–4V and Ti–35Nb–7Zr–5Ta nanotubes, with better results obtained in samples with magnesium concentration in 8.5% and the process favored the roughness in the Ti–35Nb–7Zr–5Ta group.

Bacterial response to Ti-35Nb-7Zr-5Ta alloy incorporated with calcium, phosphate and magnesium

“…The Ti-35Nb-7Zr-5Ta alloy was obtained by the arc-voltaic casting method, with inert atmosphere, controlled by vacuum pump and argon flow. After casting, the ingots were subjected to a heat treatment of homogenization at 1000 °C for 8 h (vacuum), then were forged and machined in the form of discs [ 4 ]. All discs were submitted to finishing and polishing in a polish machine with silicon carbide-SiC sandpaper (Norton Abrasivos do Brasil, São Paulo, SP, Brazil) of 120, 320, 600, 1200 and 2000 grains.…”

“…For the CaP group, we used a protocol for the formation of micropores with incorporation of Ca 2+ and PO 4 3− , in an electrolyte composed of 0.04 mol/L of sodium β-glycerophosphate (Sigma-Aldrich Co, St Loius, Mo, USA) plus 0 .35 mol/L calcium acetate (Sigma-Aldrich Co, St Loius, Mo, USA). The current source was adjusted to 300 V with varying electrical current intensity, starting at 2.5 A, for 60 s. For the Mg group, we used a magnesium acetate electrolyte at a concentration of 0.1 mol/L [ 4 ] with a voltage of 200 V, current of 2 A for 60 s.…”

“…For example, it is known that Nb leads to the formation of Nb 2 O 5 , Zr, ZrO 2 , Ta, Ta 2 O 5 , V, VO 2 and Al, Al 2 O 3 . And, that the Ti oxide modified by the oxides of Nb, Zr and Ta present better stability and, therefore, can provide better protection than the oxides of Al and V [ 3 , 4 ]. Niobium (Nb) is a typical β stabilizer of Ti alloys and has many advantages for having the same cubic centered body structure as titanium (ccc), similar atomic radius, without presenting biological toxicity.…”

Advancements in incorporating metal ions onto the surface of biomedical titanium and its alloys via micro-arc oxidation: a research review

“…Studies have indicated that Mg 2+ enhances the initial biological response surrounding implants and augments the biomechanical strength of bone integration ( Reis et al, 2020 ). Furthermore, as a biodegradable element, magnesium has attracted extensive research attention for its incorporation into biomaterials to facilitate stem cell differentiation into osteoblasts and amplify bone formation ( Sun et al, 2013 ; Li X. et al, 2018 ; Nabiyouni et al, 2018 ; Zhao Z. et al, 2021 ).…”