Cyclic oxidation of palladium modified and nonmodified aluminide coatings deposited on nickel base superalloys

Zagula-Yavorska, Maryana; Sieniawski, Jan

doi:10.1016/j.acme.2017.05.004

Cited by 15 publications

(12 citation statements)

References 14 publications

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“…Then, the aluminide coatings were deposited using the CVD equipment BPXPR0325S (IonBond Company, Olten, Switzerland) [21][22][23]. Aluminum chloride vapor (AlCl 3 ) was produced in an external generator I (IonBond Company, Olten, Switzerland) at 330 • C as a result of hydrogen chloride flow (0.2 L/min) via aluminum granules.…”

Section: Methodsmentioning

confidence: 99%

Rhodium and Hafnium Influence on the Microstructure, Phase Composition, and Oxidation Resistance of Aluminide Coatings

Zagula-Yavorska¹,

Wierzbińska²,

Sieniawski³

2017

Metals

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A 0.5 µm thick layer of rhodium was deposited on the CMSX 4 superalloy by the electroplating method. The rhodium-coated superalloy was hafnized and aluminized or only aluminized using the Chemical vapour deposition method. A comparison was made of the microstructure, phase composition, and oxidation resistance of three aluminide coatings: nonmodified (a), rhodium-modified (b), and rhodium-and hafnium-modified (c). All three coatings consisted of two layers: the additive layer and the interdiffusion layer. Rhodium-doped (rhodiumand hafnium-doped) β-NiAl phase was found in the additive layer of the rhodium-modified (rhodium-and hafnium-modified) aluminide coating. Topologically Closed-Pack (µ and σ) phases precipitated in the matrix of the interdiffusion layer. Rhodium also dissolved in the β-NiAl phase between the additive and interdiffusion layers, whereas Hf-rich particles precipitated in the (Ni,Rh)Al phase at the additive/interdiffusion layer interface in the rhodium-and hafnium-modified coating (c). The rhodium-modified aluminide coating (b) has better oxidation resistance than the nonmodified one (a), whereas the rhodium-and hafnium-modified aluminide coating (c) has better oxidation resistance than the rhodium-modified (b) and nonmodified (a) ones.

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Section: Methodsmentioning

confidence: 99%

Rhodium and Hafnium Influence on the Microstructure, Phase Composition, and Oxidation Resistance of Aluminide Coatings

Zagula-Yavorska¹,

Wierzbińska²,

Sieniawski³

2017

Metals

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“…The formation of the palladium-modified aluminide coating seems to take place in the next steps [13]: Palladium dissolution in γ + γ' phases near the surface of CMSX-4 alloy during heating of alloy with 3 µm of palladium; reaction of dissolved in the substrate palladium with aluminum; and (Ni,Pd)Al phase formation.…”

Section: Discussionmentioning

confidence: 99%

“…The amount of the γ'-Ni 3 Al phase formed under oxide layer in the rhodium-modified coatings is much smaller than in the palladium-modified and non-modified ones. It indicates that transformation from the β-NiAl phase to the γ'-Ni 3 Al phase is decelerated due to the presence of the (Ni,Rh)Al phase in the as-deposited coating [13]. Because the γ'-Ni 3 Al phase has a poor oxidation resistance, the deceleration of the γ'-Ni 3 Al phase formation leads to improvement of the oxidation resistance.…”

Section: Discussionmentioning

confidence: 99%

“…Palladium electroplating process was conducted in a bath of palladium chloride PdCl 2 -10 g/cm 3 , sulfamates acid H 2 NSO 3 -100 g/cm 3 , hydrochloric acid HCl-20 g/cm 3 and ammonium chloride NH 4 Cl-50 g/cm 3 at 35 • C. The current density during the electroplating process was about 1 A/dm 2 [13].…”

Section: Methodsmentioning

confidence: 99%

“…Ta.Substrate samples were coated by the rhodium layer (0.5 µm thick) or by the palladium layer (3 µm thick). The rhodium electroplating process was conducted in a bath of rhodium sulphate Rh 2 (SO 4 ) 3 -10 g/dm 3 , sulfuric acid H 2 SO 4 -15 g/dm 3 , and selenium acid H 2 SeO 4 -1 g/dm 3 at 50 • C. The current density during the electroplating process was about 2 A/dm 2 .Palladium electroplating process was conducted in a bath of palladium chloride PdCl 2 -10 g/cm 3 , sulfamates acid H 2 NSO 3 -100 g/cm 3 , hydrochloric acid HCl-20 g/cm 3 and ammonium chloride NH 4 Cl-50 g/cm 3 at 35 • C. The current density during the electroplating process was about 1 A/dm 2 [13].The formation of aluminide coatings is obtained by aluminizing process. Samples were aluminized with pre-deposited rhodium or palladium layers at 1040 • C for 12 h by the CVD method using the CVD BPXPR0325S equipment manufactured by the IonBond company.…”

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Oxidation Behavior of Non-Modified and Rhodium- or Palladium-Modified Aluminide Coatings Deposited on CMSX-4 Superalloy

Zagula-Yavorska

2018

Metals

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Rhodium-modified as well as palladium-modified and non-modified aluminide coatings on CMSX-4 Ni-based superalloy were oxidized in air atmosphere at 1100 • C. Uncoated substrate of CMSX-4 superalloy was also oxidized. The microstructure of coatings before oxidation consists of two layers: an additive and an interdiffusion one. The NiAl intermetallic phase was found in the microstructure of non-modified coatings, while the (Ni,Rh)Al intermetallic phase was observed in the microstructure of rhodium-modified aluminide coatings before oxidation. The (Ni,Pd)Al phase of palladium-modified aluminide coatings in the additive layer was observed before oxidation. The microstructure of the oxidized non-modified coatings consists of the γ'-Ni 3 Al phase. The oxide layer (10 µm thick) consists of the NiAl 2 O 4 phase and porous Ni-rich oxide. The oxide layers (5 µm thick) formed on the surface of rhodium or palladium-modified coatings consist of the α-Al 2 O 3 phase and the top layer of the NiAl 2 O 4 phase. Al-depleted (30 at. %) β-NiAl grains besides the γ'-Ni 3 Al phase were found in the rhodium-modified coating, while only the γ'-Ni 3 Al phase region was revealed in the palladium-modified coating, Rhodium-modified coatings with small rhodium content (0.5 µm rhodium layer thick) can be an alternative for palladium-modified ones with bigger palladium content (3 µm thick palladium layer).Wu et al. [10] introduced iridium to the aluminide coatings as a cost alternative to platinum. Firstly, the iridium layer (6 µm thick) was deposited on TMS-75 nickel-base single-crystal superalloy. Secondly, the coated superalloy was aluminized by the pack-cementation method and then cyclic oxidation tests were performed. A dense and uniform layer of the β-(Ir,Ni)Al phase was identified after aluminizing. The growth rate of oxide on Ir-Al coated superalloy was lower than on the aluminized one. Moreover, the transformation from β-NiAl phase to the γ'-phase was decelerated due to the presence of the (Ir,Ni)Al layer. The presence of iridium in the aluminide coating retarded the outward and inward diffusion of solute elements during oxidation (nickel and aluminum).The addition of 5 % wt. rhodium to the Ni-8Cr-6Al alloy increases oxide-scale adherence to the alloy and improves its oxidation resistance [11]. Rhodium addition to the aluminide coatings also increases oxidation resistance of coated alloys [12]. Therefore, rhodium-modified aluminide coatings can be an alternative for palladium-modified aluminide ones. However, there is a lack of data about comparison of the oxidation resistance of rhodium or palladium-modified aluminide coatings. That is why this paper presents comparison of the oxidation resistance of the non-modified, palladium or rhodium-modified aluminide coatings and uncoated substrate. Experimental ProcedureCMSX-4 superalloy (single-crystal) was used as a substrate material. The chemical composition of the superalloy was as follows: 61.7% wt. Ni, 6.5% wt. Cr, 9% wt. Co, 0.6% wt. Mo, 5.6% wt. Al, 1% wt. Ti, 6% wt. W, 0.1% wt. Hf, ...

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Oxidation Behavior of Overlay NiCoCrAlY and Diffusion Aluminide Coatings Deposited on a Directionally Solidified Nickel-Based Superalloy: A Comparative Study

Hosseini

Kermanpur

Ashrafizadeh

et al. 2022

JOM

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Cyclic oxidation of palladium modified and nonmodified aluminide coatings deposited on nickel base superalloys

Cited by 15 publications

References 14 publications

Rhodium and Hafnium Influence on the Microstructure, Phase Composition, and Oxidation Resistance of Aluminide Coatings

Rhodium and Hafnium Influence on the Microstructure, Phase Composition, and Oxidation Resistance of Aluminide Coatings

Oxidation Behavior of Non-Modified and Rhodium- or Palladium-Modified Aluminide Coatings Deposited on CMSX-4 Superalloy

Oxidation Behavior of Overlay NiCoCrAlY and Diffusion Aluminide Coatings Deposited on a Directionally Solidified Nickel-Based Superalloy: A Comparative Study

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