X-ray and electrostatic levitation undercooling studies in Ti–Zr–Ni quasicrystal forming alloys

Kelton, K. F.; Gangopadhyay, A. K.; Lee, G.W; Hannet, L; Hyers, R. W.; Krishnan, Shankar; Robinson, Michael B.; Rogers, J. R.; Rathz, T. J.

doi:10.1016/s0022-3093(02)01691-5

Cited by 45 publications

(39 citation statements)

References 8 publications

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“…This observation corroborates the phase diagram of Ti-Zr-Ni alloys detailed by Kelton et al for an equal ratio of Ti and Zr [16]. As shown previously, solidification of Ti 45 Zr 38 Ni 17 alloy proceeds in a complex pathway: I-phase exists, at low temperatures, in coexistence with a related 1/1 rational approximant phase, formed from a high-temperature mixture of ␤ and Laves phases.…”

Section: Effects Of Wheel Speed On the As-quenched Microstructuressupporting

confidence: 91%

“…At higher temperatures, the thermal agitation should destroy icosahedral short-range order, usually prevailing in undercooled melt. Consequently, the primary solidification products directly formed during quenching would be the bcc ␤ phase as shown in the pseudo-ternary diagram [16]. It can be noticed that the same structural state is obtained for the highest wheel speed (40 m s −1 , sample D).…”

Section: Effects Of the Temperature Of The Melt On The As-quenched Stmentioning

confidence: 81%

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

Lefaix¹,

Vermaut²,

Janičkovič³

et al. 2009

Journal of Alloys and Compounds

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Section: Effects Of Wheel Speed On the As-quenched Microstructuressupporting

confidence: 91%

Section: Effects Of the Temperature Of The Melt On The As-quenched Stmentioning

confidence: 81%

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

Lefaix¹,

Vermaut²,

Janičkovič³

et al. 2009

Journal of Alloys and Compounds

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“…Nominal composition of the alloy has been designed from Kelton et al works on the Ti-Zr-Ni systems. [30][31][32] (Fig. 1) indicates the presence of icosahedral phase (i) indexed from the scheme reported by Bancel et al…”

Section: Resultsmentioning

confidence: 99%

Surface Properties of a Nano-Quasicrystalline Forming Ti Based System

et al. 2007

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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 .

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“…This may be due to three reasons: (i) in Ti-Zr-Ni-Cu-Be system, the maximum reduced undercooling temperature for the I-phase is lower than that for simple crystal phases, and even lower than that for the polytetrahedral C14 Laves phase, indicating that I-phase shows the least interfacial free energy with the liquid phase [19,20], which leads to the prior formation of I-phase. (ii) In Ti-Zr-Ni-Cu-Be-Nb system, Nb and Ti atoms have neighbouring atomic radii (0.148 and 0.145 nm, respectively) and electronegativities (Pauling electronegativity, 1.6 and 1.54 eV, respectively) [21], so Nb atoms trend to occupy some Ti atoms positions in the I-phase structure, which may contribute to a decrease in the formation energy of I-phase.…”

Section: Discussionmentioning

confidence: 99%