Effect of Alkali-Acid-Heat Chemical Surface Treatment on Electron Beam Melted Porous Titanium and Its Apatite Forming Ability

Abstract

Advanced additive manufacturing techniques such as electron beam melting (EBM), can produce highly porous structures that resemble the mechanical properties and structure of native bone. However, for orthopaedic applications, such as joint prostheses or bone substitution, the surface must also be bio-functionalized to promote bone growth. In the current work, EBM porous Ti6Al4V alloy was exposed to an alkali acid heat (AlAcH) treatment to bio-functionalize the surface of the porous structure. Various molar concentrations (3, 5, 10M) and immersion times (6, 24 h) of the alkali treatment were used to determine optimal parameters. The apatite forming ability of the samples was evaluated using simulated body fluid (SBF) immersion testing. The micro-topography and surface chemistry of AlAcH treated samples were evaluated before and after SBF testing using scanning electron microscopy and energy dispersive X-ray spectroscopy. The AlAcH treatment successfully modified the topographical and chemical characteristics of EBM porous titanium surface creating nano-topographical features ranging from 200–300 nm in size with a titania layer ideal for apatite formation. After 1 and 3 week immersion in SBF, there was no Ca or P present on the surface of as manufactured porous titanium while both elements were present on all AlAcH treated samples except those exposed to 3M, 6 h alkali treatment. An increase in molar concentration and/or immersion time of alkali treatment resulted in an increase in the number of nano-topographical features per unit area as well as the amount of titania on the surface.

Ti6Al4V foams having nanotubular surfaces for orthopaedic applications

“…To prepare 1 × SBF, NaCl (8.035 g/L), NaHCO3 (0.355 g/L), KCl (0.225 g/L), K 2 HPO 4 .3H 2 O (0.231 g/L), MgCl 2 .6H 2 O (0.311 g/L), 1M HCl (39 mL), CaCl 2 (0.292 g/L), and Na 2 SO 4 (0.072 g/L) were dissolved in distilled water, respectively. Afterwards, the solution was buffered with Tris (6.118 g/L) and 1M HCl as per established protocols . Samples were immersed in SBF at 37°C up to 30 days.…”

“…Afterwards, the solution was buffered with Tris (6.118 g/L) and 1M HCl as per established protocols. 21 Samples were immersed in SBF at 37°C up to 30 days. The presence of calcium and phosphate elements was determined by Figure 5).…”

The Effects of Combined Micron‐Scale Surface and Different Nanoscale Features on Cell Response

“…In order to obtain micro/nanostructures, many methods have been tried, especially the combination of anodic oxidation and other methods, such as silver plasma immersion ion implantation (Ag-PIII) [23], sandblasting and acid-etching [24,25], and heat treatment [26]. It has been reported that the micro/nanocomposite surface obtained by the composite method could improve the antibacterial properties of the implant [23], the photocatalytic activity [24], the bone deposition [25], the cell response, and the apatite-forming ability [26].…”

The Sustainable Improvement of Manufacturing for Nano-Titanium

“…Specific solution directions for the research are proposed as below: (1) Enable each part of the system to meet optimal conditions (2) Pre-arrange the object or system at the most convenient time and place (3) Make all parts of an object or system work at full load (4) Introduce electric, magnetic fields to interact with an object or system (5) Restore consumable or degradable parts of an object or system during operation (6) Change the degree of flexibility Combining these solution directions, specific solution directions for the research are proposed as below:…”

“…Better corrosion protection of the implant could be expected. Bsat et al used alkali-acid-heat for surface treatment on porous titanium and improved its apatite-forming ability [3]. This could produce highly porous structures that resemble the mechanical properties and structure of native bones.…”