Solutioning and Aging of MAR-M247 Nickel-Based Superalloy

Baldan, Renato; Rocha, Rafaela Lisboa Pereira da; Tomasiello, Rafael Bogado; Nunes, Carlos Ângelo; Costa, Ana Maria Duarte Dias; Barboza, M.J.R.; Coelho, Gilberto Carvalho; Rosenthal, Ruben

doi:10.1007/s11665-013-0565-4

Cited by 49 publications

(23 citation statements)

References 8 publications

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“…The initial as-cast microstructures of the investigated alloys were similar, presenting dendritic segregations with c¢ particles and MC-type carbides dispersed in the c matrix, in agreement with other studies found in the literature for alloys with similar composition. [10][11][12][13][14][15][16][17][18] At 1000°C, parabolic oxidation behavior was observed only in the first 100 hours of oxidation for both alloys, before oxide scale spallation began to be the predominant degradation mechanism. On the other hand, the oxidation curves at 800°C and 900°C presented parabolic behavior for the entire tests' duration.…”

Section: Discussionmentioning

confidence: 99%

High Temperature Oxidation Behavior of Conventional and Nb-Modified MAR-M246 Ni-Based Superalloy

Alkmin

Chaia

Utada

et al. 2021

Metall Mater Trans A

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The present investigations focused on the thermal oxidation of two variants of MAR-M246 alloy having the same contents of Ta and Nb in at. pct, considering the effects of total replacement of Ta by Nb. The alloys were produced by investment casting using high purity elements in induction furnace under vacuum atmosphere. The alloys were oxidized pseudo-isothermally at 800°C, 900°C and 1000°C up to 1000 hours under lab air. Protective oxidation products growing on the surface of the oxidized samples were mainly Al 2 O 3 , Cr 2 O 3 . Other less protective oxide such as spinels (NiCr 2 O 4 and CoCr 2 O 4 ) and TiO 2 were also detected as oxidation products. The conventional alloy exhibited slight internal oxidation at 800°C and an enhanced resistance at 900°C and 1000°C. The Nb-modified alloy presented an exacerbated internal oxidation and nitridation at 900°C and 1000°C and an enhanced resistance at 800°C. At 1000°C, Nb-modified alloy was particularly affected by excessive spalling as the main damage mechanisms. From a kinetic point of view, both alloys exhibit the same behavior at 800°C and 900°C, with k p values typical of alumina forming alloys (2 9 10 À14 to 3.6 9 10 À13 g 2 cm À4 s À1 ). However, Ta modified alloys exhibited superior oxidation resistance at 1000°C when compared to the Nb modified alloy due to better adherence of the protective oxide scale.

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Section: Discussionmentioning

confidence: 99%

High Temperature Oxidation Behavior of Conventional and Nb-Modified MAR-M246 Ni-Based Superalloy

Alkmin

Chaia

Utada

et al. 2021

Metall Mater Trans A

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“…To obtain a preliminary evaluation of the mechanical properties, compression tests were performed on both the alloys. Figure 5a shows a plot of 0.2% proof stress versus temperature for 10Cr2Ta/10Cr2Ta2Ti alloys and compared with 2Ta/2Ta2Ti alloys, commercially available nickel (MAR-M-247) [58] and cobalt-based alloys including Co-Al-W-based alloys [20]. At room temperature 10Cr2Ta and 10Cr2Ta2Ti show 0.2% proof stress of 670 and 720 MPa, respectively, compared to 800 MPa for 2Ta and 740 MPa for 2Ta2Ti alloys.…”

Section: Mechanical Propertiesmentioning

confidence: 99%

Effect of Cr addition on γ–γ′ cobalt-based Co–Mo–Al–Ta class of superalloys: a combined experimental and computational study

et al. 2017

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The present article deals with effect of Cr addition (10 at.%) on the partitioning behavior and the consequent effect on mechanical properties for tungsten-free c-c 0 cobalt-based superalloys with base alloy compositions of Co-30Ni-10Al-5Mo-2Ta (2Ta) and Co-30Ni-10Al-5Mo-2Ta-2Ti (2Ta2Ti). Cr addition leads to a change in the morphology of the strengthening cuboidal-shaped c 0 precipitates to a spherical shape. The site preference of Cr atoms in two alloy systems (with and without Ti) has been experimentally investigated using atom probe tomography with the supportive prediction from first principles DFT-based computations. Cr partitions more to the c matrix relative to c 0 . However, Cr also has a strong effect on the Ta and Mo partitioning coefficient across c/c 0 interfaces. The value of partition coefficient for Mo (K Mo ) becomes \1 with Cr addition to the alloys. Results from ab initio calculations show that the Cr atoms prefer to replace Mo atoms in the sublattice sites of the L1 2 unit cell. The solvus temperature of about 1038 and 1078°C was measured for 10Cr2Ta and 10Cr2Ta2Ti alloy, respectively, and these Cr-containing alloys have very low densities in the range of *8.4-8.5 gm/cm -3 . The 0.2% compressive proof strength of 10Cr2Ta2Ti alloy yields a value of 720 MPa at 870°C, substantially better than most Co-Al-W-based alloys and many of the nickel-based superalloys (e.g., MAR-M-247).

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“…Moreover, hafnium contributes significantly to the grain boundary strengthening [4,12,13]. A chemical composition as well as solidification variables and multiple heat treatments immensely influenced microstructure and mechanical properties [2,[14][15][16][17] and resulted in applications of the alloy at temperatures up to about 1038…”

Section: Introductionmentioning

confidence: 99%

High-temperature low-cycle fatigue behaviour of HIP treated and untreated superalloy MAR-M247

Šulák¹,

Obrtlík²,

Čelko³

2016

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The effect of hot isostatic pressing (HIP) treatment on high-temperature low cycle fatigue (LCF) behaviour of γ precipitation strengthened nickel-based superalloy MAR-M247 was studied. Microstructural observations revealed coarse-grained dendritic structure with an average grain size of 2.1 mm. Distribution and size of casting defects were assessed on cross sections of both HIP treated and untreated MAR-M247. Shape and size of precipitates were documented. Vickers hardness tests did not reveal differences between both materials. Untreated specimens were cyclically strained under total strain control at 900• C. Likewise, tests were performed on the HIP treated material at temperatures of 900 and 950• C. The stress--strain response was recorded. Coffin-Manson and Basquin fatigue life curves were established. HIP treatment leads to an increase of lifetime in comparison with the untreated material. Precipitate depleted zone was observed and crack initiation sites were identified. Dislocation arrangements were studied in TEM. Planar bands containing antiphase boundaries were observed.K e y w o r d s : hot isostatic pressing, Ni-based superalloy, high-temperature low cycle fatigue, fatigue life curves, dislocation structures, planar bands

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Solutioning and Aging of MAR-M247 Nickel-Based Superalloy

Cited by 49 publications

References 8 publications

High Temperature Oxidation Behavior of Conventional and Nb-Modified MAR-M246 Ni-Based Superalloy

High Temperature Oxidation Behavior of Conventional and Nb-Modified MAR-M246 Ni-Based Superalloy

Effect of Cr addition on γ–γ′ cobalt-based Co–Mo–Al–Ta class of superalloys: a combined experimental and computational study

High-temperature low-cycle fatigue behaviour of HIP treated and untreated superalloy MAR-M247

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