Isothermal Oxidation Comparison of Three Ni-Based Superalloys

Mallikarjuna, H.T.; Richards, N.L.; Caley, W. F.

doi:10.1007/s11665-017-2630-x

Cited by 20 publications

(8 citation statements)

References 78 publications

(91 reference statements)

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“…The values are in the 10 À14 to 10 À12 g À2 cm À4 s À1 range from 800°C up to 1000°C, respectively, which is in good agreement with the values reported by Hindam and Whittle [19] as well as other authors. [7,[20][21][22][23] It was shown that the small modification of the MAR-M246 chemistry undertaken in the present work, i.e., substitution of Ta by Nb, has not induced a significant effect on the oxidation kinetics at 800°C and 900°C. The average parabolic constants determined from the batch of 3 samples of each alloy are in the same order of magnitude.…”

Section: Discussionmentioning

confidence: 60%

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: 60%

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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“…Based on this, the parabolic rate constants are 7 × 10 −8 , 4 × 10 −7 , and 2 × 10 −6 at 750, 825, and 900 °C, respectively. Mallikarjuna et al [32] reported that IN738LC, a polycrystalline Ni-based superalloy, has a parabolic rate constant of 2 × 10 −6 at 900 °C, identical to the constant obtained for the woven structure. The microstructures of the oxidized woven structures (after one week) are shown in Fig.…”

Section: Creep Properties Of Bulk and Woven Ni-based Superalloysmentioning

confidence: 55%

“…5b: 2 × 10 −7 s −1 at 5 MPa, 6 × 10 −7 s −1 at 6 MPa and 2 × 10 −5 s −1 at 8 MPa. The oxidation kinetics is expected to follow a parabolic relationship [32], where the parabolic rate constant can be obtained from the slope of the linear fit for each data set. Based on this, the parabolic rate constants are 7 × 10 −8 , 4 × 10 −7 , and 2 × 10 −6 at 750, 825, and 900 °C, respectively.…”

Section: Creep Properties Of Bulk and Woven Ni-based Superalloysmentioning

confidence: 99%

Experimental and modeling study of compressive creep in 3D-woven Ni-based superalloys

et al. 2018

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“…[49,51] Due to its high oxygen affinity for Ta, a more ambiguous role on protective scale formation is reported, as it may also act as an oxygen getter and by that beneficially affect the formation of protective scales. [43,52,53] This might contribute to the formation of a thin scale especially in interdendritic regions. Therefore, a lower concentration of W within dendritic regions and a simultaneously increased Ta level might together account for the beneficial impact of homogenization annealing.…”

Section: B High-temperature Oxidation At 850 °Cmentioning

confidence: 99%

Influence of the Co/Ni Ratio and Dendritic Segregations on the High-Temperature Oxidation Resistance of Multinary Co-Rich Superalloys at 850 °C and 1050 °C

Hagen

Weiser

Abu-Khousa

et al. 2022

Metall Mater Trans A

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Excellent inherent oxidation resistance is a prerequisite for the use of superalloys in many high-temperature applications. To achieve this goal, typically continuous alumina and chromia scale growths are assured through sufficient Cr and Al additions. Since the intended γ/γ′-microstructure of superalloys is only stable within a certain compositional window, the maximum concentrations of these protective scale forming elements are, however, dependent on the overall alloy composition. The latter is a severe drawback, especially for Co-rich superalloys, as for these the maximum content often is insufficient for reaching the desired continuous scale growth. In recent years, the addition of significant Ni levels was identified to improve the high-temperature oxidation properties in the case of simple model alloy systems. In this study, we compare the high-temperature oxidation behavior of two complex Co-rich multinary single-crystalline γ/γ′-strengthened superalloys that only differ regarding their Co/Ni ratios to the commercial Ni-base superalloy CMSX-4. Therefore, time-resolved isothermal gravimetric analysis (TGA) in synthetic air at 850 °C and 1050 °C for 100 hours, scanning electron microscopy analysis (SEM), and electron probe microanalysis (EPMA) were conducted. The results point out that a high Co-content beneficially affects the oxidation resistance at 850 °C, meaning that the Ni-base CMSX-4 is slightly outmatched by the Co-rich competitors. In contrast, at 1050 °C, the commercial (most Ni-rich) alloy performed best and, clearly, an increasing Co-content was identified to deteriorate the oxidation resistance. This temperature-dependent influence of the nominal Co/Ni ratio on oxidation resistance is shown to be especially pronounced for dendritic regions. Consequently, the latter could be identified to especially determine the overall oxidation kinetics.

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Isothermal Oxidation Comparison of Three Ni-Based Superalloys

Cited by 20 publications

References 78 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

Experimental and modeling study of compressive creep in 3D-woven Ni-based superalloys

Influence of the Co/Ni Ratio and Dendritic Segregations on the High-Temperature Oxidation Resistance of Multinary Co-Rich Superalloys at 850 °C and 1050 °C

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