Plasma electrolytic oxidation coatings on γTiAl alloy for potential biomedical applications

Abstract

In an attempt to enhance the potential of gamma titanium aluminide intermetallic alloy as a biomaterial, its surface characteristics were successfully modified using a calcium and phosphorous rich electrolyte through the application of plasma electrolytic oxidation. Scanning electron microscopy and atomic force microscopy were used to characterize the morphology and topographical features of the resulting coating while X-ray diffraction and energy dispersive spectroscopy were used to determine the surface oxide composition. The mechanical properties of the surface coating were characterized by nanoindentation studies. The results observed show the formation of a submicron scale porous structure and a concomitant increase in the surface roughness. The surface oxide was composed of rutile and anatase phases. Composition gradients of Ca and P were also present which can possibly enhance the biomaterial application potential of this treated surface. Nanoindentation measurements indicate the formation of a fairly compact oxide during the process.

Electrochemical behavior of bioactive coatings on cp-Ti surface for dental application

“…Titanium (Ti) and its alloys are the most common used implant materials for medical and dental applications due to their biocompatibility and corrosion resistance [1, 2]. A thin oxide layer is normally formed on the substrate when exposed to air, but no strong bond is formed between them.…”

Corrosion behavior of plasma electrolytically oxidized gamma titanium aluminide alloy in simulated body fluid

“…For example, Al 2 O 3 is known to be an insulator whilst Nb 2 O 3 and VO x are semi-conductive in nature. The characterization of the PEO coating, its growth mechanism and the principal compositional and morphological features related to the process parameters used in each of the alloys under study were made by using different techniques [61]. Coating features were strongly dependent on the current density values and the resulting voltage for plasma electrolysis used and were specific to each alloy.…”

The effects of micro arc oxidation of gamma titanium aluminide surfaces on osteoblast adhesion and differentiation

“…The metal disks were dried and then oxidized by the micro arc process at a constant temperature and current. Based on earlier results [21], applied current values of 200 mA and 225 mA (current density values of 520 mA/cm 2 and 585 mA/cm 2 respectively) and treatment times of 3 minutes and 4 minutes were selected for both alloys. The MAO alloys were then placed in 48-well culture plates (Corning, Corning, New York) and cells were seeded on these materials as described in Section 2.4.…”

“…The electrolyte used for MAO consisted of 0.025M Ca(H 2 PO 4 ) 2 , 0.075M Ca(OOCCH 3 ) 2 and 0.12 M Na 2 (EDTA) dissolved in ultra-pure water [21]. The basic component of the electrolyte is calcium dihydrogen phosphate with a Ca/P ratio of 0.5.…”