The high-temperature strength of some Fe3Al alloys

Morris, David G.; Muñoz-Morris, Ma Antonia; Baudin, C.

doi:10.1016/j.actamat.2004.02.031

Cited by 101 publications

(72 citation statements)

References 39 publications

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“…It is well known that iron-aluminide alloys exhibit limited strength and creep resistance at high temperatures and low ductility at ambient temperatures [9,10]. The introduction of second phases as precipitate particles is one of the common practices used to overcome these weaknesses [11][12][13]. In the case of iron-rich aluminides, the addition of small amount of carbon, that may lead to the presence of the E2 1 -Fe 3 AlC precipitate (known as K-carbide phase), is used to enhance the high-temperature mechanical properties.…”

Section: Introductionmentioning

confidence: 99%

Atomistic study of magnetism effect on structural stability in Fe₃Al and Fe₃AlX (X = H, B, C, N, O) alloys

Kellou¹,

Grosdidier²,

Raulot³

et al. 2008

Physica Status Solidi (b)

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Atomistic modeling based on the density‐functional theory (DFT) within the generalized‐gradient approximation (GGA) is used to study the magnetic properties Fe3Al and Fe3AlX (X = H, B, C, N, O) compounds. The phase stability and the structural parameters are calculated for the selected iron‐aluminide alloys. The magnetic effects in Fe3AlX are shown and the predicted properties agree very well with the available experimental data. In the case of Fe3Al alloy, the DO3 structure is found to be more favorable than the L12 one. To the authors' knowledge, this is the first time that spin‐polarized GGA calculations have given the correct ground state of the Fe3Al alloys. In addition, the hypothetical phase of Fe3AlX′ (X′ = H, B, N, and O) structure is compared to the experimentally observed Fe3AlC structure. The unusual effect on magnetic properties of the C addition is shown. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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Section: Introductionmentioning

confidence: 99%

Atomistic study of magnetism effect on structural stability in Fe₃Al and Fe₃AlX (X = H, B, C, N, O) alloys

Kellou¹,

Grosdidier²,

Raulot³

et al. 2008

Physica Status Solidi (b)

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“…Somewhat similar research has been conducted at CENIM, Spain, with an emphasis on obtaining fine phases, of high stability against coarsening when possible, by heat treatments for precipitation of intermetallic or carbide phases, such as Fe 2 NbAl Heusler, Fe 3 Zr, or Mo, W carbides. [21][22][23] This study has also examined the decomposition of FeNiAl alloys, leading to a b 0 -g mixture with good strength at high temperature. [24] Figure 2 shows examples of fine intermetallic precipitates in some iron aluminide matrices, leading to good strength at temperatures around 700 8C.…”

Section: Improvements Of Creep Strength Of Cast Materialsmentioning

confidence: 99%

“…[24] Figure 2 shows examples of fine intermetallic precipitates in some iron aluminide matrices, leading to good strength at temperatures around 700 8C. [21,22] These studies have shown that very high strength, including good creep behavior, can be achieved for very high temperatures, but this is often obtained at the expense of any useful ductility. The requirement of sufficient ductility imposes a major restriction on alloy chemistry and requires that the microstructure comprise a relatively soft matrix with finely dispersed stable particles of the second phase.…”

Section: Improvements Of Creep Strength Of Cast Materialsmentioning

confidence: 99%

Recent Developments Toward the Application of Iron Aluminides in Fossil Fuel Technologies

Morris¹,

Muñoz-Morris²

2010

Adv Eng Mater

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Iron aluminides are of interest for applications in power generation from fossil fuels because of excellent high temperature oxidation–corrosion resistance in aggressive environments and are potential replacements for high temperature steels. The Fe‐base composition ensures relative cheapness, while the high Al content leads to significant density reduction over commercial steels. Problems of low ductility/toughness at room temperature and poor high temperature (creep) strength, however, have prevented significant commercial use. After studies led by Oak Ridge National Laboratory (USA) from about 1980 to 2000, research has continued in Europe both as pan‐European efforts and as national efforts in countries such as the Czech Republic, France, Germany and Spain. An overview of such recent activities is presented, indicating the research strategies involved, and the progress toward making iron aluminides useful engineering materials. Recent activities have targeted microstructural refinement through novel processing to improve room temperature ductility or attempted alloying additions to improve high temperature strength. Achieving the required properties remains difficult, and has led to developments of iron aluminides as cast components and as coatings.

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“…On the other hand, it was reported that Nb forms several different types of precipitates around 900°C that could degrade high-temperature strength and thermal fatigue resistance [6]. Morrie et al [8] noted that rapid coarsening of the Laves phase at high temperatures significantly reduces strength over 973K(700°C), and Sim et al [9] reported that coarse, rod-shaped Laves phase precipitates (Fe 2 Nb) formed at 973K(700°C) are very detrimental to high-temperature strength of Nbcontaining steels. With regard to practical applications, there are many studies of the thermal and fatigue behavior [10][11][12][13] and the high-temperature deformation behavior [14][15][16][17] of high Cr stainless steels.…”

Section: Introductionmentioning

confidence: 99%

“…Niobium-(Nb) containing ferritic stainless steels were developed to overcome the lower high-temperature strength [1][2][3]. Niobium improves high-temperature strength and thermal fatigue resistance by solid-solution hardening and precipitation hardening [4][5][6][7][8][9]. Fujita et al [4] reported that fine Nb carbo-nitrides and Nb-based Laves phase precipitates formed during hightemperature deformation improve the strength of the alloy at 1173K(900°C).…”

Section: Introductionmentioning

confidence: 99%

Effect of Laves Phase on High-Temperature Deformation and Microstructure Evolution in an 18Cr-2Mo-0.5Nb Ferritic Stainless Steel

Ikeda

Yamoah

Reynolds

et al. 2015

Metall Mater Trans A

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Niobium-containing ferritic stainless steels are finding new applications in automotive exhaust components because of their oxidation resistance, thermal fatigue resistance, and high-temperature strength. The mechanical behavior of Nb-containing ferritic steels at service temperatures of 973K(700°C) and higher results from the convolution of dynamic microstructural changes including precipitation, precipitate coarsening, strain hardening, recovery, and recrystallization. The relative contributions of these competing processes have yet to be clarified. In this study, the high-temperature flow strength of an 18Cr-2Mo-0.5Nb ferritic stainless steel (SUS 444) was correlated with microstructure under different strain and initial precipitate distributions to clarify the relative role of the strengthening and softening processes. High-temperature tensile tests at 1023K(750°C) of un-aged (initial 2 microstructure is precipitate-free) and pre-aged (initial microstructure contains precipitates) samples were carried out and transmission electron microscopy was used to assess dislocation distributions and precipitate morphology. The difference in the stress-strain curves between un-aged and pre-aged samples was drastic; the yield strength of the un-aged sample was twice that of the pre-aged sample, and the unaged sample exhibits a noticeable yield drop. Transmission electron microscopy revealed a Laves phase nucleated and grew during the high-temperature tensile test in the un-aged sample and the majority of the precipitates in the pre-aged sample were the same Laves phase. Furthermore, a strain effect on precipitate growth was recognized in un-aged and pre-aged conditions by comparing grip (no strain) and gauge (strained) sections of tensile samples. The dominant strengthening contribution in un-aged samples is initially the precipitate shearing mechanism and it changes to Orowan strengthening beyond the ultimate tensile strength, whereas the dominant contribution in the pre-aged samples appears to be Orowan strengthening throughout the stress-strain curve.

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The high-temperature strength of some Fe3Al alloys

Cited by 101 publications

References 39 publications

Atomistic study of magnetism effect on structural stability in Fe₃Al and Fe₃AlX (X = H, B, C, N, O) alloys

Atomistic study of magnetism effect on structural stability in Fe₃Al and Fe₃AlX (X = H, B, C, N, O) alloys

Recent Developments Toward the Application of Iron Aluminides in Fossil Fuel Technologies

Effect of Laves Phase on High-Temperature Deformation and Microstructure Evolution in an 18Cr-2Mo-0.5Nb Ferritic Stainless Steel

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The high-temperature strength of some Fe3Al alloys

Cited by 101 publications

References 39 publications

Atomistic study of magnetism effect on structural stability in Fe3Al and Fe3AlX (X = H, B, C, N, O) alloys

Atomistic study of magnetism effect on structural stability in Fe3Al and Fe3AlX (X = H, B, C, N, O) alloys

Recent Developments Toward the Application of Iron Aluminides in Fossil Fuel Technologies

Effect of Laves Phase on High-Temperature Deformation and Microstructure Evolution in an 18Cr-2Mo-0.5Nb Ferritic Stainless Steel

Contact Info

Product

Resources

About

Atomistic study of magnetism effect on structural stability in Fe₃Al and Fe₃AlX (X = H, B, C, N, O) alloys

Atomistic study of magnetism effect on structural stability in Fe₃Al and Fe₃AlX (X = H, B, C, N, O) alloys