Characterization of Alumina Scales Grown on a 2nd Generation Single Crystal Ni Superalloy During Isothermal Oxidation at 1050, 1100 and 1150 °C

Swadźba, Radosław; Swadźba, L.; Wiedermann, J.; Hetmańczyk, M.; Witala, B.

doi:10.1007/s11085-014-9487-2

Cited by 44 publications

(15 citation statements)

References 38 publications

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“…Hf, Zr and Y. There are a number of research works proving the positive influence of reactive elements on high temperature oxidation processes [2][3][4], however the exact mechanism of their influence is still unclear. There is experimental evidence indicating that the presence of Hf, Y and Zr has a particularly positive effect on the oxidation processes of alloys that form oxide scales composed of Al 2 O 3 or Cr 2 O 3 , which leads to [4][5][6][7][8]:…”

Section: Introductionmentioning

confidence: 99%

INFLUENCE OF HAFNIUM ON HIGH TEMPERATURE OXIDATION OF NiAl AND Ni3Al ALLOYS

Swadźba¹,

Staszica²

2018

PIMZ

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The results presented in this paper concern the modification of NiAl and Ni 3 Al alloys with reactive elements that increase their high temperature oxidation resistance. Literature data indicate that even trace additions of Hf to aluminide coatings significantly improve the resistance to oxidation in the range of 1100-1150°C, however the exact mechanism of its influence is not yet known. In order to determine the influence of various additions of Hf on high temperature oxidation of aluminide coatings, cyclic oxidation tests were performed at 1150°C of model NiAl and Ni 3 Al alloys with different Hf additions-from 0.25 wt.% to 1.5 wt.%. High resolution electron microscopy, as well as chemical composition analysis techniques, were applied to perform a detailed characterisation of the influence of Hf on the substructure, chemical and phase composition in the nano scale of oxide scales formed during high temperature oxidation.

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Section: Introductionmentioning

confidence: 99%

INFLUENCE OF HAFNIUM ON HIGH TEMPERATURE OXIDATION OF NiAl AND Ni3Al ALLOYS

Swadźba¹,

Staszica²

2018

PIMZ

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“…Complex transient Ni(Al,Cr)2O4 spinel, and (Ti,Cr,Al)(Ti,Ta)O4 rutile, and NiTa2O6 tri-rutile were reported in addition to more common NiO and Al2O3 structures [10]. Elegant cross-sectional STEM characterizations have documented Ta, Hf, Y, and Zr segregation at grain boundaries in the alumina scale formed at 1050-1150 °C on a Ni-6.1Al-7.3Cr-7.3Co-4.9W-6.5Ta-1.5Mo-2.9Re-0.15Hf-0.01Zr-0.02Y 2nd generation single crystal superalloy, most closely resembling doped Rene′ N5 [11]. The morphologies and transition from initial θ-Al2O3 to steady-state α-Al2O3 were also documented.…”

Section: Introductionmentioning

confidence: 99%

Cyclic Oxidation of High Mo, Reduced Density Superalloys

Smialek

Garg

Gabb

et al. 2015

Metals

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Cyclic oxidation was characterized as part of a statistically designed, 12-alloy compositional study of 2nd generation single crystal superalloys as part of a broader study to co-optimize density, creep strength, and cyclic oxidation. The primary modification was a replacement of 5 wt. % W by 7% or 12% Mo for density reductions of 2%-7%. Compositions at two levels of Mo, Cr, Co, and Re were produced, along with a midpoint composition. Initially, polycrystalline vacuum induction samples were screened in 1100 °C cyclic furnace tests using 1 h cycles for 200 h. The behavior was primarily delimited by Cr content, producing final weight changes of −40 mg/cm 2 to −10 mg/cm 2 for 0% Cr alloys and −2 mg/cm 2 to +1 mg/cm 2 for 5% Cr alloys. Accordingly, a multiple linear regression fit yielded an equation showing a strong positive Cr effect and lesser negative effects of Co and Mo. The results for 5% Cr alloys compare well to −1 mg/cm 2 , and +0.5 mg/cm 2 for Rene′ N4 and Rene′ N5 (or Rene′ N6), respectively. Scale phases commonly identified were Al2O3, NiAl2O4, NiTa2O6, and NiO, with (Ni,Co)MoO4 found only on the least resistant alloys having 0% Cr and 12% Mo. Scale microstructures were complex and reflected variations in the regional spallation history. Large faceted NiO grains and fine NiTa2O6 particles distributed along NiAl2O4 grain boundaries were typical distinctive features. NiMoO4 formation, decomposition, and volatility occurred for a few high Mo compositions. A creep, density, phase stability, and oxidation balanced 5% Cr, 10% Co, 7% Mo, and 3% Re alloy was selected to be taken forward for more extensive evaluations in single crystal form. OPEN ACCESSMetals 2015, 5 2166

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“…In the caseswith the oppsit premise, sulfides could not be observed in the alloy. From another viewpoint, RE elements would "site block" at the grain boundaries to inhibit the outward diffusion of Al 3+ [14][15][16]. Recently, a new perspective was put forward by Arthur H. Heuer and David B. Hovis, that REs could affect oxidation behavior by reducing both the diffusion of O 2to grain boundaries and the Al ionization [17].…”

Section: Introductionmentioning

confidence: 99%

Effect of Y on the Oxidation Behavior of a Directionally Solidified Ni-based Single Crystal Superalloy

Zhao

Guan

Cui

et al. 2020

Preprint

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The effect of Y addition on the oxidation behavior of a Ni-based directionally solidified single crystal superalloy was investigated. Isothermal oxidation test for the samples with different-level Y addition was conducted at 1100℃ in air. The Y content of the samples was demarcated by the actual pickup amount resulted from ICP-AES test. It was found that the addition of Y increased the oxide resistance by an adhesive double-layer oxide scale which was composed of Al2O3 and spinel Ni(Cr,Al)2O4. With 70ppm Y addition, the oxidation weight gain was decreased from 12.6g/m2 for the alloy without Y addition to 5.3g/m2, and the oxidation rate was significantly decreased. Besides, the internal nitride also disappeared after Y doping because of the increasing oxidation scale adherence and the decreasing of oxidation products. In this study, 660ppm Y addition alloy showed the best oxidation resistance.

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Characterization of Alumina Scales Grown on a 2nd Generation Single Crystal Ni Superalloy During Isothermal Oxidation at 1050, 1100 and 1150 °C

Cited by 44 publications

References 38 publications

INFLUENCE OF HAFNIUM ON HIGH TEMPERATURE OXIDATION OF NiAl AND Ni3Al ALLOYS

INFLUENCE OF HAFNIUM ON HIGH TEMPERATURE OXIDATION OF NiAl AND Ni3Al ALLOYS

Cyclic Oxidation of High Mo, Reduced Density Superalloys

Effect of Y on the Oxidation Behavior of a Directionally Solidified Ni-based Single Crystal Superalloy

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