The effect of alloying elements on oxide scale spallation of multicomponent Co-based superalloys

Migas, Damian; Moskal, G.; Myalska, Hanna; Mikuszewski, T.

doi:10.1016/j.corsci.2021.109787

Cited by 14 publications

(6 citation statements)

References 43 publications

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“…Within this layer, some multiphase zones (p. 5), rich in Al, were found. Oxides of such morphology are characteristic for internal oxidation zone [4]. The inner oxide zones of the alloy oxidized at 800, 900, and 1000 °C are also rich in O, Co, Al, and W. However, their morphology is not similar to that of γ-γ′.…”

Section: Resultsmentioning

confidence: 99%

“…Oxidation resistance is one of the most important factors limiting the overall durability of hightemperature components. The oxidation resistance of the alloys is much lower compared to that of nickelbased superalloys [4]. The protective properties against oxidation at high temperatures depend on the scale structure.…”

Section: Introductionmentioning

confidence: 96%

“…The inner oxide zone is composed of CoO and Co-Al and Co-W spinel oxides. Such structures of the oxide scales do not provide oxidation protection and are prone of thermal shock [4].…”

Section: Introductionmentioning

confidence: 99%

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Microstructural characterization of oxide scales formed on γ–γ′ Co-Al-W-based superalloys

MIGAS

Moskal

Chmiela

et al. 2022

METAL 2022 Conference Proeedings

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Cobalt superalloys based on the Co-Al-W system are a new group of heat-resistant materials, which have attracted attracted the interest of researchers in 21 th century. The advantage of the new materials over conventional cobalt alloys is the strengthening mechanism based on a microstructure of the γ-γ′ type. This study concerned microstructural study of the oxidation products formed on the Co-9Al-9W (at.%) alloy during isothermal oxidation at different temperatures. Therefore, the alloy was prepared via vacuum induction melting (VIM) and casting to a graphite mold. The alloy was subjected to a two-step heat treatment. In the first step, the alloy was annealed at 1250 °C for 16 h in a tubular furnace and are then water quenched. Afterwards, the ingot was annealed at 900 °C for 100 h.The oxidation tests were carried out on cylindrical samples, which were ground, polished and degreased. The oxidation oxide scale formation of the alloy was examined under isothermal conditions in the range 500-1000 °C. The morphology of oxides was examined by scanning electron microscopy (SEM), and their composition was analyzed energy dispersive spectroscopy (EDS). The structures of scales formed at different temperatures were compared.Oxidation at 500 °C results in growth of monolayer scale of Co-oxides, whereas at higher temperatures, multilayer scales are formed. The scales usually consists of outer scale of cobalt oxides, inner oxide layers composed of a mixture of CoO and Co-spinels, and internal oxidation zone.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 96%

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Microstructural characterization of oxide scales formed on γ–γ′ Co-Al-W-based superalloys

MIGAS

Moskal

Chmiela

et al. 2022

METAL 2022 Conference Proeedings

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“…In the past decade, researchers have focused on the oxidation behavior of simple Co-(Ni)-Al-W alloys (Forsik et al, 2018;Migas et al, 2018) and the influence of main alloying elements (Ni, Cr, Al, etc.) on the oxidation behavior of alloys (Migas et al, 2021;Berthod et al, 2021aBerthod et al, , 2021b. However, drawing on the research experience of Ni-based superalloys, the addition of micro-alloying elements will also have a crucial impact on the oxidation resistance of the alloy while affecting the mechanical properties and microstructure stability of the alloy (Klein et al, 2011;Liang et al, 2021aLiang et al, , 2021b.…”

Section: Introductionmentioning

confidence: 99%

Effects of trace elements Hf and Si on oxidation behavior of Co-Ni-Al-W-based superalloys at 900°C

Zhou

Zhang

et al. 2022

ACMM

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Purpose This study aims to control the oxidation resistance of Co-based deformed superalloys by adding trace elements Hf and Si. Design/methodology/approach The effects and mechanism of trace elements Hf and Si on the oxidation behavior of Co-Ni-Al-W-based forged superalloys were investigated by cyclic oxidation at 900°C. Findings The results show that the addition of trace elements Hf and Si does not affect the type of surface oxides of Co-Ni-based superalloys, and the oxidation layers of the alloys are TiO2, spinel, Cr2O3, TaTiO4, Al2O3 and TiN from outside to inside. However, the addition of elements can affect the activity of Cr and Ti elements; decrease the formation of TiO2 and TaTiO4 layers, which are harmful to the oxidation performance; and then improve the oxidation resistance of the alloy. Originality/value The relevant research results can not only optimize the microalloying element content of Co-Ni-Al-W-based superalloys, but also provide a new perspective for the composition optimization design of superalloys.

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“…The major advantage of a Co-based alloy in comparison with Ni-based alloys are their better mechanical properties [27], higher melting temperature [28] and high resistance against corrosion and sulfidation [29,30]. Studies on oxidation behavior of Co-based superalloys revealed that they possess relatively high oxidation resistance [31][32][33][34][35]. It is known that aluminide layers increase high temperature oxidation of Ni-based alloys.…”

Section: Introductionmentioning

confidence: 99%

Increase in Oxidation Resistance of MAR M-509 via LA-CVD Aluminizing

et al. 2021

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Due to their excellent mechanical properties, Co-based alloys are one of the main candidates to replace Ni-based alloys in high temperature application. Knowledge about oxidation resistance of Co-based alloy MAR M-509 and the extent of its aluminizing on its oxidation resistance is limited. Therefore, in the present study, an aluminide layer was manufactured by low activity chemical vapor deposition (LA-CVD) on MAR M-509. Aluminized and uncoated alloys were investigated in terms of oxidation kinetics and oxidation resistance during isothermal and cyclic oxidation at 1000 and 1100 °C. Material in the as-cast and after exposure was analyzed using scanning electron microscopy (SEM), thermogravimetry (TG) and glow-discharge optical emission spectrometry (GD-OES). Obtained results allowed for elucidating of degradation mechanism including nitridation process of carbides for MAR M-509. It was found that aluminizing of MAR M-509 significantly decreases its oxidation kinetics by the factor of 2.5 and 1.5 at 1000 and 1100 °C respectively. Moreover, the suppression of identified degradation mechanism in case of aluminized alloy was found until occurrence of breakaway oxidation of the aluminide layer. It was also proposed that further increase in oxidation resistance can be successively achieved by an increase in aluminide layer thickness.

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The effect of alloying elements on oxide scale spallation of multicomponent Co-based superalloys

Cited by 14 publications

References 43 publications

Microstructural characterization of oxide scales formed on γ–γ′ Co-Al-W-based superalloys

Microstructural characterization of oxide scales formed on γ–γ′ Co-Al-W-based superalloys

Effects of trace elements Hf and Si on oxidation behavior of Co-Ni-Al-W-based superalloys at 900°C

Increase in Oxidation Resistance of MAR M-509 via LA-CVD Aluminizing

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