Solid-Solution Strengthening by Oxygen in Nb-Ta and Nb-Mo Single Crystals

Miura, Eri; Yoshimi, Kyosuke; Hanada, Shuji

doi:10.1002/1521-396x(200106)185:2<357::aid-pssa357>3.0.co;2-9

Cited by 14 publications

(4 citation statements)

References 17 publications

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“…Unfortunately, as far as we have surveyed, reasonable activation energy values for the impurity diffusion of Si and Ti in Mo have not yet been reported. For the activation energy of creep in Mo-Si-B-based alloys, more careful discussion of impurity diffusion and interstitial (I)-substitutional (S) impurity interaction effects may be needed 35 , 36 . Most of the authors listed in Table 3 reported stress exponents between 3 and 5.…”

Section: Discussionmentioning

confidence: 99%

Ultrahigh-temperature tensile creep of TiC-reinforced Mo-Si-B-based alloy

Kamata

Kanekon

et al. 2018

Sci Rep

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In this study, the ultrahigh-temperature tensile creep behaviour of a TiC-reinforced Mo-Si-B-based alloy was investigated in the temperature range of 1400–1600 °C at constant true stress. The tests were performed in a stress range of 100–300 MPa for 400 h under vacuum, and creep rupture data were rationalized with Larson-Miller and Monkman-Grant plots. Interestingly, the MoSiBTiC alloy displayed excellent creep strength with relatively reasonable creep parameters in the ultrahigh-temperature range: a rupture time of ~400 h at 1400 °C under 137 MPa with a stress exponent (n) of 3 and an apparent activation energy of creep (Qapp) of 550 kJ/mol. The increasing rupture strains with decreasing stresses (up to 70%) and moderate strain-rate oscillations in the creep curves suggest that two mechanisms contribute to the creep: phase boundary sliding between the hard T2 and (Ti,Mo)C phases and the Moss phase, and dynamic recovery and recrystallization in Moss, observed with orientation imaging scanning electron microscopy. The results presented here represent the first full analysis of creep for the MoSiBTiC alloy in an ultrahigh-temperature range. They indicate that the high-temperature mechanical properties of this material under vacuum are promising.

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Section: Discussionmentioning

confidence: 99%

Ultrahigh-temperature tensile creep of TiC-reinforced Mo-Si-B-based alloy

Kamata

Kanekon

et al. 2018

Sci Rep

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“…ii) The solute O atoms may interact with screw and edge dislocations and impede the dislocation motion [21].…”

Section: Discussionmentioning

confidence: 99%

The Deformation Behavior of Oxygen-Modified Ti-29Nb-13Ta-4.6Zr(wt.%)

et al. 2020

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A series of Ti-29Nb-13Ta-4.6Zr(wt.%) {TNTZ} alloys containing either 0.1, 0.3 or 0.7(wt.%) oxygen (O) were room-temperature tensile tested inside a scanning electron microscope to evaluate the effect of O on the deformation evolution. The deformation modes observed for TNTZ-0.1O, which exhibited the largest elongation-to-failure and lowest strength of all the alloys, were deformation-induced α”-martensitic transformation, {332}<113> twinning, and <111> slip. For the other two alloys, <111> slip was the dominant deformation mode, where TNTZ-0.7O exhibited more homogeneous and extensive slip, a higher frequency of cross slip, and a higher work-hardening rate, all of which contributed to both its strength and elongation-to-failure being greater than that for TNTZ-0.3O. TNTZ-0.3O exhibited the greatest tendency for cracking, which generally occurred on grain boundaries perpendicular to the tensile axis, leading to the lowest elongation-to-failure of all the alloys.

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“…Loomis and Gerber 54) reported that CRSS of Nb single crystal increases linearly wih O+N+C concentration up to 0.2 mol% with a hardening rate of 170 MPa/mol%(O+N+C). Miura et al 55) showed that CRSS of Nb-4.55 mol%O is 600 MPa with the average hardening rate of 130 MPa/ mol%O, while in Nb-20Ta-O single crystals CRSS increases linearly with oxygen concentration with a rate of 240 MPa/ mol%O. The present result of the average hardening rate of 175 MPa/mol%O seems consistent with the above results.…”

Section: Strengthening Mechanisms Of Gum Metal At Room Temperaturementioning

confidence: 99%

Basic Deformation Mechanism of Bcc Titanium-Based Alloy of Gum Metal

et al. 2016

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Single crystals and cold-swaged polycrystalline specimens of Gum Metal of Ti-36Nb-2Ta-3Zr-0.3O (mass %) have been compressed with the stress-relaxation test in the temperature range from 77 K to 450 K. In both single crystals and cold-swaged specimens, the yield stress decreases with increasing temperature rapidly to the room temperature and then gently above it forming a plateau at high temperature. The activation analysis of plastic deformation showed that the applied shear stress dependence of activation enthalpy and that of activation volume for single crystals and those for cold swaged specimens are almost identical if we shift the stress scale by about 120 MPa, meaning that the basic deformation mechanism is common to both samples. The above results are contradictory with the previously proposed non-dislocation deformation mechanism at the ideal shear strength, but consistent with the established features of usual bcc alloys, i.e., the deformation is governed by the Peierls mechanism at low temperature and by defect hardening at high temperature. τ χ − χ and ψ − χ relations of single crystals showed a typical slip asymmetry seen in bcc metals, where slip in Gum Metal belongs to the {112} slip type as in binary Ti-Nb single crystals reported previously (S. Hanada et al.: Metall. Trans. A 16 (1985) 789). Yielding by massive {332}〈113〉 twin formation in single crystals at low temperatures was observed for the rst time in Gum Metal.

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Solid-Solution Strengthening by Oxygen in Nb-Ta and Nb-Mo Single Crystals

Cited by 14 publications

References 17 publications

Ultrahigh-temperature tensile creep of TiC-reinforced Mo-Si-B-based alloy

Ultrahigh-temperature tensile creep of TiC-reinforced Mo-Si-B-based alloy

The Deformation Behavior of Oxygen-Modified Ti-29Nb-13Ta-4.6Zr(wt.%)

Basic Deformation Mechanism of Bcc Titanium-Based Alloy of Gum Metal

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