Structural Study of Novel Nanocrystalline fcc Ti-Ta-Sn Alloy

Aguilar, C.; Pio, E.; Medína, A.; Mangalaraja, R.V.; Salvo, Christopher; Alfonso, I.; Guzmán, Danny; Béjar, L.

doi:10.1007/s11661-019-05152-w

Cited by 14 publications

(7 citation statements)

References 24 publications

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“…Studying the pattern of both milled powders in detail, the diffraction peaks of Ti-γ were identified (in 2θ = 36.2°, 42.1°, and 61.2°), which is a metastable phase (FCC) with the Fm3m space group, which should not be confused with the Ti-β phase, which is also a cubic structure (BCC) but has an Im3m space group and should have diffraction peaks in 2θ = 38.5°, 55°, and 69°, peaks that are missing in the pattern. It has been reported that the formation of this metastable phase by ball-milling is driven by the accumulation of partial dislocations and stacking faults induced by high plastic deformation and nanocrystalline grain size [ 63 , 64 , 65 , 66 , 67 ]. In addition, the presence of diffraction peaks of YSZ is associated with the contamination that comes from the milling media.…”

Section: Resultsmentioning

confidence: 99%

Effect of the Processing Parameters on the Porosity and Mechanical Behavior of Titanium Samples with Bimodal Microstructure Produced via Hot Pressing

et al. 2021

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Commercially pure (c.p.) titanium grade IV with a bimodal microstructure is a promising material for biomedical implants. The influence of the processing parameters on the physical, microstructural, and mechanical properties was investigated. The bimodal microstructure was achieved from the blends of powder particles with different sizes, while the porous structure was obtained using the space-holder technique (50 vol.% of ammonium bicarbonate). Mechanically milled powders (10 and 20 h) were mixed in 50 wt.% or 75 wt.% with c.p. titanium. Four different mixtures of powders were precompacted via uniaxial cold pressing at 400 MPa. Then, the specimens were sintered at 750 °C via hot pressing in an argon gas atmosphere. The presence of a bimodal microstructure, comprised of small-grain regions separated by coarse-grain ones, was confirmed by optical and scanning electron microscopies. The samples with a bimodal microstructure exhibited an increase in the porosity compared with the commercially available pure Ti. In addition, the hardness was increased while the Young’s modulus was decreased in the specimens with 75 wt.% of the milled powders (20 h).

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Section: Resultsmentioning

confidence: 99%

Effect of the Processing Parameters on the Porosity and Mechanical Behavior of Titanium Samples with Bimodal Microstructure Produced via Hot Pressing

et al. 2021

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“…This route could be explained as being due to the allotropic transformation of the TiNbMn alloy from a bcc to fcc crystallographic structure. Although this allotropic transformation is not common in beta-stabilized Ti alloys (bcc-Ti alloys), it has been previously reported in systems with Nb as a main alloying element, such as the Ti-30Nb-13Ta-2Mn alloy, Ti-Nb-Ta system, and TiNbxMn (x = 0-12 wt.%), among others [8,9,11,13,24]. This transformation is directly associated with the combination of the Nb content and mechanical milling, as first reported by Chattopadhyay et al [28].…”

Section: Microstructural Charactrizationmentioning

confidence: 94%

“…This final stable phase seems to be achieved after 12 h of milling time for the PL20 specimen, or after 18 h for the SP10 and PL10 specimens. Therefore, the time required to reach the full transformation of raw powders to the fcc phase is relatively short in comparison with similar studies on Ti fcc phase formation, such as the Ti-Ta-Sn system (Ti-13Ta-6Sn [24]), and the Ti-Nb-Ta-Mn system (Ti-30Nb-13Ta-2Mn [13]), where milling times between 50-100 h were necessary. The corresponding peak to the Fe contamination presented in all of the specimens that were milled for 18 h and 24 h, showed an increasing intensity for both the milling times, according to the following sequence: SP10 → PL10 → PL20.…”

Section: Microstructural Charactrizationmentioning

confidence: 96%

Effect of Milling Parameters on the Development of a Nanostructured FCC–TiNb15Mn Alloy via High-Energy Ball Milling

García-Garrido

Sepúlveda

Salvo

et al. 2021

Metals

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In this work, a blend of Ti, Nb, and Mn powders, with a nominal composition of 15 wt.% of Mn, and balanced Ti and Nb wt.%, was selected to be mechanically alloyed by the following two alternative high-energy milling devices: a vibratory 8000D mixer/mill® and a PM400 Retsch® planetary ball mill. Two ball-to-powder ratio (BPR) conditions (10:1 and 20:1) were applied, to study the evolution of the synthesized phases under each of the two mechanical alloying conditions. The main findings observed include the following: (1) the sequence conversion evolved from raw elements to a transitory bcc-TiNbMn alloy, and subsequently to an fcc-TiNb15Mn alloy, independent of the milling conditions; (2) the total full conversion to the fcc-TiNb15Mn alloy was only reached by the planetary mill at a minimum of 12 h of milling time, for either of the BPR employed; (3) the planetary mill produced a non-negligible Fe contamination from the milling media, when the highest BPR and milling time were applied; and (4) the final fcc-TiNb15Mn alloy synthesized presents a nanocrystalline nature and a partial degree of amorphization.

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“…Finally, the formation of the -Ti was analysed because it appeared in major quantity. Common characteristics to synthesize the  phase are high deformation and nanocrystalline grain size [61]. Figure 9 shows the XRD pattern for the Ti-33Nb-4Mn alloy for milling times between 1 and 120 h. At 1 h, reflections of the elemental powders Ti, Nb and Mn can be observed.…”

Section: Ti-nb-ta Systemmentioning

confidence: 99%

“…Finally, the formation of the γ-Ti was analysed because it appeared in major quantity. Common characteristics to synthesize the γ phase are high deformation and nanocrystalline grain size [61]. Figure 10 shows the Gibbs free energy of mixing values diagram to form a solid solution for the Ti-Nb-Ta system at 298 K. The ∆G m values are negative in the zone close to the Ti-Mn binary system and positive close to the Nb-rich corner.…”

Section: Ti-nb-ta Systemmentioning

confidence: 99%

Thermodynamic Analysis of the Formation of FCC and BCC Solid Solutions of Ti-Based Ternary Alloys by Mechanical Alloying

Aguilar

Martínez

Tello

et al. 2020

Metals

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A thermodynamic analysis of the synthesis of face-centred cubic (fcc) and body-centred cubic (bcc) solid solutions of Ti-based alloys produced by mechanical alloying was performed. Four Ti-based alloys were analysed: (i) Ti-13Ta-3Sn (at.%), (ii) Ti-30Nb-13Ta (at.%), (iii) Ti-20Nb-30Ta (wt. %) and (iv) Ti-33Nb-4Mn (at.%). The milled powders were characterized by X-ray diffraction, and the crystallite size and microstrain were determined using the Rietveld and Williamson-Hall methods. The Gibbs free energy of mixing for the formation of a solid solution of the three ternary systems (Ti-Ta-Sn, Ti-Nb-Ta and Ti-Nb-Mn) was calculated using an extended Miedema's model, applying the Materials Analysis Applying Thermodynamics (MAAT) software. The values of the activity of each component were determined by MAAT. It was found that increasing the density of crystalline defects, such as dislocations and crystallite boundaries, changed the solubility limit in these ternary systems. Therefore, at longer milling times, the Gibbs free energy increases, so there is a driving force to form solid solutions from elemental powders. Finally, there is agreement between experimental and thermodynamic data confirming the formation of solid solutions.Author Contributions: Conceptualization, C.A. and C.M.; methodology, C.A. and F.S.M.; software, C.A.; validation, I.A.; formal Analysis, C.A., C.M. and S.P.; investigation, C.A., F.S.M. and K.T.; writing-original draft preparation, C.A., S.P. and A.D.; writing-review and editing, S.P., A.D., K.T. and I.A.; visualisation, C.A. and I.A.; project administration, C.A.; funding acquisition, C.A. and K.T. All authors have read and agreed to the published version of the manuscript. Funding:The authors would like to acknowledge the financial support received from the FONDECYT project n 1190797 and FONDEQUIP/EQM project n 140095. Conflicts of Interest:The authors declare no conflict of interest.

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Structural Study of Novel Nanocrystalline fcc Ti-Ta-Sn Alloy

Cited by 14 publications

References 24 publications

Effect of the Processing Parameters on the Porosity and Mechanical Behavior of Titanium Samples with Bimodal Microstructure Produced via Hot Pressing

Effect of the Processing Parameters on the Porosity and Mechanical Behavior of Titanium Samples with Bimodal Microstructure Produced via Hot Pressing

Effect of Milling Parameters on the Development of a Nanostructured FCC–TiNb15Mn Alloy via High-Energy Ball Milling

Thermodynamic Analysis of the Formation of FCC and BCC Solid Solutions of Ti-Based Ternary Alloys by Mechanical Alloying

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