Metastable phases of electron type in titanium alloys with 3d-metals

Носова, Г. И.; D’yakonova, N. B.; Lyasotskii, I. V.

doi:10.1007/s11041-006-0111-1

Cited by 17 publications

(20 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[8] In that study, selected area diffraction patterns obtained using transmission electron microscopy were observed to contain reflections consistent with the metastable incommensurate omega phase, which is known to form in the A2 phase on rapid cooling in Ti-Fe-based alloys. [15,16] Based on this work, the shoulders to lower angles observed on the A2 reflections in the present work are similarly believed to correspond to the presence of an omega phase with somewhat larger plane spacing than the parent A2 phase, with the peaks broadened as a result of the fine crystallite size. [8] In addition to reflections from the A2 phase, the X-ray diffraction patterns collected from alloys TF20M10, TF20M20, and TF20M40 were also found to contain strong reflections from a B2 phase.…”

Section: Resultssupporting

confidence: 68%

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: Resultssupporting

confidence: 68%

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

“…In addition, this result is in accordance with conclusions from refs. showing the formation of athermal ω in a limited compositional range between 3 and 5 wt% Fe. With increasing local Fe content, the crystal structure of ω becomes distorted, as it can be seen from the decreasing intensity and from the diffuse shape of the additional reflections belonging to ω‐Ti(Fe).…”

Section: Resultsmentioning

confidence: 99%

“…In contrast, the isothermal ω phase precipitates during annealing experiments involving diffusion processes (as a consequence of the diffusion of alloying elements) . For Ti–Fe alloys, the formation of the athermal ω phase was reported to occur between 3 and 5 wt% Fe . For Fe contents higher than 5 wt%, the β phase is retained in the quenched sample as a metastable phase …”

Section: Introductionmentioning

confidence: 99%

Thermal Stability of Athermal ω‐Ti(Fe) Produced upon Quenching of β‐Ti(Fe)

et al. 2018

View full text Add to dashboard Cite

This work shows the formation of the athermal ω phase in alloy Ti-4 wt% Fe. The alloy under study, heat treated at 800 C for 100 h and subsequently water quenched, is investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The thermal stability of ω-Ti(Fe) is investigated by differential scanning calorimetry (DSC). The DSC measurements show a cascade of several thermic events between 160 and 450 C, and one strong and sharp exothermic DSC peak at $480 C. The phase transformations and other microstructural changes behind these events are explained by complementary use of XRD, electron backscatter diffraction (EBSD), and TEM analyses that are performed on samples heated stepwise in the DSC apparatus. These experiments indicate that the embryos of athermal ω-Ti(Fe) grow up to $400 C and start to decompose into an α-Ti(Fe) þ β assemblage already at 450 C. At $480 C, the decomposition of the athermal ω-Ti(Fe) phase is practically finished. Thermal stability of athermal ω-Ti(Fe) is compared with the thermal stability of ω-Ti(Fe) produced in a high-pressure torsion (HPT) process, indicating a higher thermal stability of ω-Ti(Fe) in the non-deformed alloys.

show abstract

“…In the Ti–Fe system, several metastable phases were reported, which form as a result of quenching from the bcc‐type β solid solution . For low Fe contents (≤5 wt% Fe), the hexagonal close packed α ′‐martensite (SG: P 6 3 / mmc ) can be obtained after quenching, whereas in a limited compositional range between 3 and 5 wt% Fe, the formation of athermal ω ‐Ti(Fe) (SG: P 6/ mmm ) was reported . At higher Fe contents, the β phase remains as a metastable phase in the samples after quenching.…”

Section: Introductionmentioning

confidence: 99%

Transformation Pathway upon Heating of Ti–Fe Alloys Deformed by High‐Pressure Torsion

et al. 2018

View full text Add to dashboard Cite

The current work presents the results of a study of the thermal stability of metastable ω-Ti(Fe) produced by a high-pressure torsion process and describes the phase transformations of ω-Ti(Fe) upon heating. The titanium alloys under study contain between 1 and 7 wt% of iron, the phase transitions are investigated using a combination of in situ high-temperature X-ray diffraction and differential scanning calorimetry. The high-temperature X-ray diffraction reveals the phase sequence ω ! α' ! α þ β ! β upon heating. The differential scanning calorimetry shows that the first phase transformation is exothermal and that the temperature of this phase transition is independent of the iron concentration within the composition range under study. Subsequent phase transitions are endothermal and the respective transition temperatures depend on the iron concentration. The differences between the phase stabilities conclude from the phase diagram and the phase stabilities observe experimentally are explained by the partial coherence of the α/α 0 -Ti and β-Ti grains.

show abstract

Metastable phases of electron type in titanium alloys with 3d-metals

Cited by 17 publications

References 9 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)

Thermal Stability of Athermal ω‐Ti(Fe) Produced upon Quenching of β‐Ti(Fe)

Transformation Pathway upon Heating of Ti–Fe Alloys Deformed by High‐Pressure Torsion

Contact Info

Product

Resources

About