Surface Properties of a Nano-Quasicrystalline Forming Ti Based System

Abstract

Two decades of intense research on quasicrystalline materials have suggested their potential use as surface coatings, considering their low coefficient of friction, high hardness, good corrosion and wear resistances and low surface energy. In that sense, quasicrystals could be introduced into the field of biomaterials since biomolecules are well known to be sensitive to solid surface properties. In this paper we report on investigations of the early stage of oxidation of the quasicrystals forming Ti 45 Zr 38 Ni 17 alloy and its surface reactivity with respect to an aminoacid. After analysing the microstructure of as-quenched ribbons both by transmission electron microscopy and X-ray diffraction, surface oxide layers were characterized by X-ray Photoelectron Spectroscopy (XPS). Oxidation of Ti 45 Zr 38 Ni 17 results in the formation of a ZrO 2 /TiO 2 barrier oxide layer, avoiding toxic Ni release. This latter is mainly present at the oxide/alloy interface. Thereafter, adsorption of L-glutamic acid has been investigated by infrared spectroscopy. Even if this biomolecule is found to adsorb to each substrate, it seems to display different adsorption mechanisms on quasicrystalline ribbons compared to that on pure titanium (CpTi) or on pure zirconium (Zr), leading to a weaker signal on Ti 45 Zr 38 Ni 17 . We discuss these results along with the affinities of each alloying metal to oxygen and with the peculiar electronic properties of quasicrystals which could affect the surface properties of Ti 45 Zr 38 Ni 17 .

Processing and characterization of rapidly quenched Ti-based alloys: Influence of solidification rate on the as-quenched structures

“…In accordance with previous results on this ternary alloys [2,9], these reflections have been assigned to an icosahedral phase I, indexed from the scheme reported by Bancel et al [14]. The quasilattice constant a q = 0.517 ± 0.001 nm matches parameters mentioned elsewhere [10,15]. In addition, the amorphous phase seems to have totally disappeared since no diffuse halo is visible anymore, neither on the XRD pattern, nor on the SAED (Fig.…”

Unusual devitrification behaviour in rapidly solidified Ti45Zr38Ni17 alloy

“…The ternary Ti-Zr-Ni alloy presents great scientific and technological interests since a highly ordered icosahedral phase, displaying great thermal stability, has been previously described in this system [4]. Its ability to absorb large amount of hydrogen (up to 1.6 hydrogen per metallic atom) has been extensively studied by Kelton et al [4,22] and the present authors have recently underlined the potential interest of these alloys for biomedical applications, taking advantages from the unusual combination of surface properties [23]. Recently, Qiang has showed that the phase selection pattern in this ternary system is rather complex since lots of phases, from Laves phases to intermetallics, could be achieved [24].…”

Structural phase transitions in the Ti45Zr38Ni17−xFex nano-alloys and their deuterides

“…Namely, they might be used for high temperature protective coatings [1], biomedical applications [2], metal-hydride based batteries [3], and memory shape alloys [4]. It seems that the hydrogen sorption properties, e.g.…”