Effect of boron on grain-boundaries in Ni3Al†

Liu, Chang; White, C.L.; Horton, J.A.

doi:10.1016/0001-6160(85)90139-7

Cited by 1,003 publications

(245 citation statements)

References 27 publications

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“…Alloying with elements that form Heusler phase precipitates has been demonstrated as a useful way to solve this problem. [2,6,7,[11][12][13][14] Particularly the control of the twophase microstructure of the CsCl and the Heusler phases turned out to be very important. [5] Isopleths were established for the sections NiAl-TiNi 2 Al, [5] FeAl-TiFe 2 Al, [15] Fe 3 Al-TiFe 2 Al-FeAl, [16,17] NiAl-TiNi 2 Al-TiNi, [15,18,19] TiNi 2 AlTiNi, [20] and (Fe, Ni)Al-Ti (Fe, Ni).…”

Section: Introductionmentioning

confidence: 99%

The Heusler Phase Ti25(Fe50 − x Ni x )Al25 (0 ≤ x ≤ 50); Structure and Constitution

Yan

Grytsiv

Rogl

et al. 2008

J Phs Eqil and Diff

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Alloys with composition Ti 25 (Fe 50 2 x Ni x )Al 25 (0 £ x £ 50) were investigated employing electron probe microanalysis (EPMA) and X-ray powder diffraction (XPD). For TiFe 2 Al, in situ neutron powder diffraction (ND) was used for the inspection of phase constitution covering the temperature range from 27°C (300 K) to 1277°C (1550 K). Combined Rietveld refinement of ND and XPD data for TiFe 2 Al revealed that Fe atoms occupy the 8c site in space group Fm " 3m; Ti with a small amount of Al sharing the 4a site, and the remaining Ti and Al atoms adopting the 4b site. This structural model was successfully applied in the refinement of all alloys Ti 25 (Fe 50 2 x Ni x )Al 25 (0 £ x £ 50). Partial atom order exists on the Fe-rich side while complete order is observed for the Ni-rich side. Profiles recorded by in situ neutron powder diffraction for TiFe 2 Al in the range of investigated temperatures show two phases, namely Heusler phase and MgZn 2 -type Laves phase. Diffraction peaks from the Heusler phase dominate the profiles at lower temperatures but at higher temperatures the MgZn 2 -type Laves phase is the main phase. No CsCl-type phase was found in the alloy in the investigated temperature range. The thermal expansion coefficient of TiFe 2 Al is 1.4552310 25 K 21 .

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Section: Introductionmentioning

confidence: 99%

The Heusler Phase Ti25(Fe50 − x Ni x )Al25 (0 ≤ x ≤ 50); Structure and Constitution

Yan

Grytsiv

Rogl

et al. 2008

J Phs Eqil and Diff

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“…We show that (a) fracture strengths of Ni/boride interfaces are higher than the Ni-Σ5 grain boundaries and coherent Ni/Ni 3 Future work in this area would involve exploring different orientation relationships in γ/boride interfaces and also incorporating other variants such as γ/boride interfaces, to develop a more complete understanding of the effects of boride precipitates in the microstructures of Ni-based superalloys. Keeping in mind the synergistic interplay between different alloying elements and their effects on mechanical responses of interfaces, it would be interesting to extend the current calculations beyond Ni to capture the effect of multi-element γ composition on interfacial strengths.…”

Section: Discussionmentioning

confidence: 94%

“…A simplified way to characterize a grain boundary between two grains involves the coincidence-site-lattice (CSL) model, in which the relative orientation of the two grains is given by a ΣN value, where one out of N atoms along the grain boundary is coincident [5]. Hanada et al [6] and Lin et al [7] have established that in Ni 3 Al, lowangle and Σ3 symmetrical boundaries are especially resistant to cracking and therefore are considered as "strong boundaries". J. Q. Su et al [8] furthered this study by establishing that while Σ1, Σ3, and Σ9 boundaries in Ni3Al are crack-resistant, Σ5, Σ7, Σ11, Σ13 and random boundaries are weaker, fracturing preferentially to the bulk intragranular material.…”

Section: Introductionmentioning

confidence: 99%

Interfaces in Ni-based Superalloys and Implications for Mechanical Behavior and Environmental Embrittlement: A First-principles Study

Sanyal¹,

Waghmare²,

Hanlon³

et al. 2012

Superalloys 2012 (Twelfth International Symposium)

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Motivated by the vital role played by grain boundaries and interfaces in Ni-based superalloys in influencing mechanical properties such as creep rupture strength, fatigue crack growth rates and resistance towards environmental embrittlement, we use first-principles simulations to estimate fracture strengths of Ni Σ3(111) grain boundary, Ni Σ5(012) grain boundary, Ni/Ni 3 Al interfaces and Ni/boride interfaces through determination of their work of separation. We find that Ni/boride interfaces have higher fracture strengths than the other commonly occurring interfaces in Ni-alloys, such as NiΣ5 & NiΣ3 grain boundaries and coherent Ni/Ni 3 Al interfaces, and are less susceptible to oxygen-induced embrittlement. Our calculations show how the presence of Mo at Ni/M 5 B 3 (M = Cr, Mo) interfaces leads to additional reduction in oxygen-induced embrittlement. Through Electron-LocalizationFunction based analyses, we identify the electronic origins of effects of alloying elements on fracture strengths of these interfaces and observe that chemical interactions stemming from electronegativity differences between different atomic species are responsible for the trends in calculated strengths. Our findings should be useful towards designing Ni-based alloys with higher interfacial strengths and reduced oxygen-induced embrittlement.

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“…percent in the air-cooled condition. Boron is perhaps the most widely recognized remedial segregant and is associated with increased resistance to intergranular fracture in many alloys, from ferrit ic Fe-Mn [52,53] to Ni3Al intermetallics [54][55][56]. Both pair-potential theory and the quantum calculations of Briant and Messmer [64] predict that B increases the interfacial cohesion of steels.…”

Section: Control Of Intergranular Fracturementioning

confidence: 99%

“…such as C in alloy steels [50.51]. and B in both ferritic [52.53] and austenitic materials [54][55][56], The tendency for impurity elements to segregate to interfaces. such as grain boundaries.…”

mentioning

confidence: 99%

Control of cryogenic intergranular fracture in high-manganese austenitic steels

Strum¹

1986

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Effect of boron on grain-boundaries in Ni3Al†

Cited by 1,003 publications

References 27 publications

The Heusler Phase Ti25(Fe50 − x Ni x )Al25 (0 ≤ x ≤ 50); Structure and Constitution

The Heusler Phase Ti25(Fe50 − x Ni x )Al25 (0 ≤ x ≤ 50); Structure and Constitution

Interfaces in Ni-based Superalloys and Implications for Mechanical Behavior and Environmental Embrittlement: A First-principles Study

Control of cryogenic intergranular fracture in high-manganese austenitic steels

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