Relationship between the volume of the unit cell of hexagonal-close-packed Ti, hardness and oxygen content after α-case formation in Ti–6Al–2Sn–4Zr–2Mo–0.1Si alloy

Baillieux, Jean; Poquillon, Dominique; Malard, B.

doi:10.1107/s1600576715022906

Cited by 12 publications

(15 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Increasing oxygen concentra on leads to the increase of the la ce parameters and thus to the expansion of the volume of tanium unit cell [22,27]. Studies [28][29][30] demonstrate approaches that allow the assessment of oxygen concentra on in tanium by the parameters of its crystal la ce. Capability of the XRD analysis of diffusion layer is limited to the depth of X-ray penetra on and is substan ally complicated by the presence of oxygen concentra on gradient, which forms a diffrac on pa�ern resul ng from the superposi on of the diffracted radia on.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Study of oxygen content in titanium alloys after exposure at elevated temperature

Kalienko

Волков²,

Ледер³

et al. 2020

MATEC Web Conf.

View full text Add to dashboard Cite

Isothermal oxidation testing of near α titanium alloys VT18U, VT20, Ti6Al7Nb and Ti6242S was performed in air at 560 °С for 1000 hours. Parameters of diffusion layer on the alloy surfaces were studied by microhardness indentations, optical microscopy, X-ray diffraction analysis and nuclear microanalysis. It was established that concentration of oxygen in diffusion layer of tested alloys after oxidation differs significantly. An approach was demonstrated and validated by nuclear microanalysis data that allows comparative evaluation of the total concentration of interstitial impurities in the diffusion layer by the X-ray diffraction method.

show abstract

Section: Resultsmentioning

confidence: 99%

“…Measurement of hardness of diffusion layer is an effec ve tool for analyzing oxygen gradient in diffusion layer [13,27,30]. It is obvious that the observed difference in oxygen concentra on near the oxide/metal interface of the studied alloys determines the oxygen gradient in the en re diffusion layer, Fig.…”

Section: Resultsmentioning

confidence: 99%

Study of oxygen content in titanium alloys after exposure at elevated temperature

Kalienko

Волков²,

Ледер³

et al. 2020

MATEC Web Conf.

View full text Add to dashboard Cite

show abstract

“…2). This model proposed by Strafford and Towell [20] is based on the work of Rosa et al who found a linear relationship between microhardness and oxygen content up to 2 wt% in a β-Ti alloy between 932 and 1142 °C [21] and was generalized to α, near-α and α-β alloys for all temperatures [22][23][24].…”

Section: Modeling Of Microhardness Profilesmentioning

confidence: 99%

Oxygen Diffusion Modeling in Titanium Alloys: New Elements on the Analysis of Microhardness Profiles

Vaché

Monceau

2020

Oxid Met

View full text Add to dashboard Cite

This study focuses on the diffusion of oxygen in titanium alloys during high-temperature oxidation. In particular, the model used to obtain thermokinetic coefficients from microhardness profiles was investigated. A literature review shows that microhardness profiles are modeled by a simple error function in the same way as oxygen concentration profiles obtained by microprobe analysis (EPMA). The analysis of literature shows that the hypothesis of a linear relationship between microhardness and oxygen content is not true over the entire oxygen concentration range and that a parabolic relationship is empirically more accurate. A new modeling equation taking into account this parabolic law is proposed as well as a simplified and easier to use form. The relative error of the diffusion coefficients obtained using the simplified equation was then determined. This new model was applied to the experimental microhardness profile of a Ti-6242s sample oxidized at 625 °C. The resulting oxygen diffusion coefficient is in excellent agreement with the one determined from EPMA profile using the classic error function model. Finally, other data from literature were analyzed with the new model to obtain an Arrhenius diagram of oxygen diffusivity in Ti-64 alloy between 550 and 850 °C. This diagram gives thermokinetic coefficients D 0 = 1.1 × 10 −5 exp −191 kJ/mol RT that are close to those reported for pure α-Ti in the temperature range 550-850 °C.

show abstract

“…The purpose was to identify the affected depth and compare it to Castaing EPMA. At 600°C, following previous validated and published method [22][23][24][25], it was then possible to identify an effective diffusion coefficient of oxygen in the metal (7.6 10 -17 . m².s -1 ) in very good agreement with previous data [25].…”

Section: Oxidation Kinetics and Oxygen Diffusion Zone Beneath The Oximentioning

confidence: 99%

“…Strengthening structural alloys with the addition of solute atoms is wildly used. For titanium alpha or near alpha alloys, the lattice parameters a and c of alpha-titanium increase with the local oxygen content [22][23] as well as the Young Modulus [24]. However few studies have been devoted to understand the effect of oxygen on plasticity at the atomic scale.…”

Section: Conclusion and Perspectivementioning

confidence: 99%

Oxidation of Ti–6Al–4V alloy between 450 and 600°C. Evolution of microstructure and mechanical properties

et al. 2020

View full text Add to dashboard Cite

Titanium alloys are widely used in many applications thanks to their good corrosion resistance and to their high specific modulus. However, at temperatures above 450°C, oxidation must be taken into account to improve life assessment of components. Especially for long-term exposures, oxidation leads to an oxide scale along with an oxygen enrichment in the metal below this oxide scale. In this study, the oxidation behaviour of Ti– 6Al–4V is investigated between 450 and 600°C for a maximum duration of about 6800 h. Scanning electron microscope (SEM) and transmission electron microscopy (TEM) are used to characterize the oxide layer and the layer affected by oxygen uptake. The local oxygen content is quantified. Vibration tests are performed to determine elastic properties on thin specimens with different thicknesses affected by oxygen enrichment. Creep tests are also carried out to quantify the influence of this oxygen uptake on viscoplastic behaviour. An oxygen-enriched zone occupying 5% of the cross-section of a specimen is sufficient to induce detectable changes in its creep behaviour.

show abstract

Relationship between the volume of the unit cell of hexagonal-close-packed Ti, hardness and oxygen content after α-case formation in Ti–6Al–2Sn–4Zr–2Mo–0.1Si alloy

Cited by 12 publications

References 21 publications

Study of oxygen content in titanium alloys after exposure at elevated temperature

Study of oxygen content in titanium alloys after exposure at elevated temperature

Oxygen Diffusion Modeling in Titanium Alloys: New Elements on the Analysis of Microhardness Profiles

Oxidation of Ti–6Al–4V alloy between 450 and 600°C. Evolution of microstructure and mechanical properties

Contact Info

Product

Resources

About