Formation of a bimodal structure in ultrafine Ti–Fe–Nb alloys with high-strength and enhanced ductility

Cao, Guanghui; Peng, Y.F.; Liu, N.; Li, X.; Lei, Zixuan; Ren, Zhong; Gerthsen, D.; Russell, Alan M.

doi:10.1016/j.msea.2014.04.088

Cited by 34 publications

(20 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The X-ray data also indicated the presence of an A2 phase in this alloy, which is believed to be the acicular precipitates. The bright BSE contrast of these precipitates is consistent with a high 25.2 ± 1.5 52.8 ± 0.8 22.0 ± 1.1 TF20M70 A2 7.7 ± 0.4 7.4 ± 1.5 84.9 ± 1.9 D8 5 15. Mo concentration, as may be expected in such an A2 phase.…”

Section: B Microstructural Characterizationsupporting

confidence: 72%

“…These alloys have been shown to possess strengths up to 2 GPa and elongations to failure of 15 pct. [1][2][3][4][5] An alternative approach by which a microstructure containing these phases can be generated is through precipitation of the B2 phase from an A2 matrix. This approach is attractive as it offers the possibility of greater microstructural control than can be achieved through an invariant reaction.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Phase Equilibria in the Fe-Mo-Ti Ternary System at 1173 K (900 °C) and 1023 K (750 °C)

Knowles

Jones

et al. 2017

Metall Mater Trans A

View full text Add to dashboard Cite

Alloys with fine-scale eutectic microstructures comprising Ti-based A2 and TiFe B2 phases have been shown to have excellent mechanical properties. In this study, the potential of alloys with further refined A2-B2 microstructures formed through solid-state precipitation has been explored by analyzing a series of six alloys within the Fe-Mo-Ti ternary system. Partial isothermal sections of this system at 1173 K (900°C) and 1023 K (750°C) were constructed, from which the ternary solubility limits of the A2 (Ti, Mo), B2 TiFe, D8 5 Fe 7 Mo 6 , and C14 Fe 2 Ti phases were determined. With these data, the change in solubility of Fe in the A2 phase with temperature, which provides the driving force for precipitation of B2 TiFe, was determined and used to predict the maximum potential volume fraction of B2 TiFe precipitates that may be formed in an A2 (Ti, Mo) matrix.

show abstract

Section: B Microstructural Characterizationsupporting

confidence: 72%

Section: Introductionmentioning

confidence: 99%

Phase Equilibria in the Fe-Mo-Ti Ternary System at 1173 K (900 °C) and 1023 K (750 °C)

Knowles

Jones

et al. 2017

Metall Mater Trans A

View full text Add to dashboard Cite

show abstract

“…Notably, the lamellar microstructure in both prior phases of alloy TF20M40 was exceptionally fine, having a width of ~ 20 nm and an interlamellae spacing of ~ 50 nm. The structure bears a resemblance to the microstructure obtained through a eutectic reaction in TiTiFe alloys, which are reported to have impressive mechanical properties [4,9]. However, the lamellar microstructure observed in alloy TF20M40, generated by solid state precipitation, is approximately an order of magnitude finer than those of the eutectic alloys.…”

Section: Precipitation Heat Treatmentmentioning

confidence: 55%

“…Ternary additions of Nb, V, Co and Sn have been shown to refine the A2-B2 lamellae, leading to improvements in the mechanical properties, with strengths of up to 2.5 GPa and elongations to failure of 15 % [7][8][9][10][11]. However, in such A2-B2 eutectic alloys, the cooling rate during solidification has been found to be critical in producing the optimal microstructures [7].…”

Section: Introductionmentioning

confidence: 99%

Phase Equilibria and Properties of Ti‐Fe‐Mo Alloys With Ultra‐Fine Lamellar Microstructures

Knowles

Jones

et al. 2016

Proceedings of the 13th World Conference on Titanium

View full text Add to dashboard Cite

Recent studies have identified exceptional mechanical properties in eutectic A2-B2 alloys based on the Ti-Fe binary system. Ternary additions have been shown to refine the microstructure and further enhance the mechanical properties. However, at present, the related ternary phase diagrams are not well defined, and, in particular, the extent of the two-and three-phase fields are poorly characterised. In this study, the phase equilibria in the TiMo rich region of the Ti-Fe-Mo ternary system have been evaluated through microstructural examination of a series of alloys. Attention was focussed on establishing the limits of solubility of Fe in the A2 phase close to the solidus temperatures, to facilitate the development of alloys containing B2 precipitates within an A2 matrix. An extensive A2-B2 two-phase field was identified, in which the solubility of Fe in the A2 phase decreased with increasing Mo content. In addition, the B2 phase was observed to accommodate up to 10 at.% Mo. A large two-phase field between A2 (Ti,Mo) and D8 5 (Fe 7 Mo 6 ) was also observed for Mo rich compositions. Two-step heat treatments, comprising a high temperature solution step and a lower temperature precipitation step, produced microstructures with fine B2 (TiFe) precipitates. The addition of Mo led to a change in the precipitate morphology from spherical to lamellar, with further additions resulting in a dramatic refinement to a lamellar nanostructure. Microhardness measurements showed that material with this ultrafine lamellar structure had a hardness > 7 GPa.

show abstract

“…However, when the molybdenum content is 3 at.% or more, the alloys consist of a fully retained b phase, Figure 2c-e. As the molybdenum content increases from 3 at.% to 7 at.%, the diffraction peaks of the cubic b titanium are gradually shifted to higher diffraction angles. The lattice parameters of the b phase in the 3Mo, 5Mo, and 7Mo alloys are measured to be 0.347 nm, 0.345 nm, and 0.342 nm, respectively, which are larger than that of pure b titanium (0.331 nm) owing to dissolution with zirconium and molybdenum [24]. Moreover, because of the smaller atomic radius of molybdenum (1.39 Å ) compared to titanium (1.47 Å ) and zirconium (1.62 Å ), the addition of molybdenum causes a decrease in the b-phase lattice parameter [25,26].…”

Section: Resultsmentioning

confidence: 88%

Microstructures and mechanical properties of as‐cast titanium–zirconium–molybdenum ternary alloys

Yang

Wang

Shi

et al. 2018

Materialwissenschaft Werkst

Self Cite

View full text Add to dashboard Cite

In this study titanium-zirconium-molybdenum alloys (Ti 50 Zr 50 ) 100-x Mo x (xMo; x = 0 at.%, 1 at.%, 3 at.%, 5 at.% or 7 at.%) were investigated, focusing on the effect of molybdenum addition on their microstructures and mechanical properties. Transmission electron microscopy observations revealed that the binary Ti 50 Zr 50 alloy was composed entirely of an acicular hexagonal structure of the a' phase. When the molybdenum content was 1 at.%, the alloy was composed of b and w phases. However, when 3 at.% or more molybdenum was added, only the equiaxed, retained b phase was observed. Tensile tests at room temperature indicated that the mechanical properties of the 1Mo alloy were inferior owing to the embrittlement effects of the w phase and the difficulty of dislocation motion through the w phase. Our research suggested that the 5Mo alloy had excellent ductility (16.5 %) as well as adequate strength (780 MPa). The improved mechanical properties were attributed to the enhanced stability of the b phase and the disappearance of the w phase.

show abstract

Formation of a bimodal structure in ultrafine Ti–Fe–Nb alloys with high-strength and enhanced ductility

Cited by 34 publications

References 22 publications

Phase Equilibria in the Fe-Mo-Ti Ternary System at 1173 K (900 °C) and 1023 K (750 °C)

Phase Equilibria in the Fe-Mo-Ti Ternary System at 1173 K (900 °C) and 1023 K (750 °C)

Phase Equilibria and Properties of Ti‐Fe‐Mo Alloys With Ultra‐Fine Lamellar Microstructures

Microstructures and mechanical properties of as‐cast titanium–zirconium–molybdenum ternary alloys

Contact Info

Product

Resources

About