Microstructure degradation of simple, Pt- and Pt+Pd-modified aluminide coatings on CMSX-4 superalloy under cyclic oxidation conditions

Swadźba, Radosław; Hetmańczyk, M.; Wiedermann, J.; Swadźba, L.; Moskal, G.; Witala, B.; Radwański, Krzysztof

doi:10.1016/j.surfcoat.2012.06.093

Cited by 32 publications

(18 citation statements)

References 25 publications

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“…Swadźba et al [15] identified also Al 2 O 3 oxides after oxidation of aluminide coatings, but in the presented research, Al 2 O 3 oxides were not found.…”

Section: Non-modified Aluminide Coating After the Oxidation Testcontrasting

confidence: 66%

“…Swadźba et al [15] identified also Al2O3 oxides after oxidation of aluminide coatings, but in the presented research, Al2O3 oxides were not found. After oxidation, non-modified aluminide coating consists of the aluminum depleted γ'-Ni3Al phase (Figure 5a-c).…”

Section: Non-modified Aluminide Coating After the Oxidation Testcontrasting

confidence: 66%

“…After oxidation, non-modified aluminide coating consists of the aluminum depleted γ'-Ni3Al phase (Figure 5a-c). Swadźba et al [15] allege that presence of γ'-Ni3Al phase is a result of β→ γ' transformation which occurred due to the aluminum depletion from the β phase. The γ' phase contains about 11 at.…”

Section: Non-modified Aluminide Coating After the Oxidation Testmentioning

confidence: 99%

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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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“…Swadźba et al [15] identified also Al 2 O 3 oxides after oxidation of aluminide coatings, but in the presented research, Al 2 O 3 oxides were not found.…”

Section: Non-modified Aluminide Coating After the Oxidation Testcontrasting

confidence: 66%

Section: Non-modified Aluminide Coating After the Oxidation Testcontrasting

confidence: 66%

Section: Non-modified Aluminide Coating After the Oxidation Testmentioning

confidence: 99%

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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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“…While the oxidation of modified aluminide bond coatings has been studied in detail by now, during the recent years some interest has been devoted to Pd ? Pt [23,30,31] modified aluminide coatings that provide excellent oxidation resistance and can be considered as bond coatings for TBC systems. Although bare superalloys are rarely applied on components operating at high temperatures it is important to study their behavior under such conditions in order to evaluate the influence of novel coatings further on.…”

Section: Introductionmentioning

confidence: 99%

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

Swadźba

Wiedermann

et al. 2014

Oxid Met

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This paper concerns microstructural characterization of alumina scales formed on a 2nd generation single crystal Ni superalloy during isothermal oxidation in dry oxygen at 1050, 1100 and 1150°C for 100 h. Samples for high resolution characterization of Al 2 O 3 scales were prepared using a focused ion beam (FIB) method. High resolution TEM and S/TEM techniques were used for a detailed characterization and a direct comparison of the phase composition and chemistry of the oxide scales formed during high temperature oxidation. The growth of transient h-Al 2 O 3 and its transformation to a-alumina is addressed for each oxidation temperature along with the differences in the diffusion of reactive elements, such as Hf, Zr and Y, through grain boundaries of the a phase. The h to a transformation front was proven to move from the metal-scale to the scale-gas interface. The results presented in this paper indicate that after 100 h of oxidation at 1050 and 1100°C there are still some h-alumina grains remaining and even in the regions where the transformation to a was finished the surface retained the whisker-like morphology.

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“…Initially due to the Pt cost issue, a research group of the National Institute for Materials Science (NIMS, Japan) suggested to replace Pt-rich coatings by Ir-based bond-coatings [15,16], as it has been tested for Pd before [17][18][19][20][21]. Iridium has the second highest melting point (2716 K) amongst the Pt group metals.…”

Section: Introductionmentioning

confidence: 99%

Chromium and iridium effects on the short-term interdiffusion behaviour between Pt rich γ-γ′ bond-coatings and a Ni-Al-Cr alloy

Audigié

Put

Murakami

et al. 2017

Surface and Coatings Technology

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To cite this version:Pauline Audigié, Aurélie Rouaix-Vande Put, Hideyuki Murakami, Daniel Monceau. Chromium and iridium effects on the short-term interdiffusion behaviour between Pt rich γ-γ' bond-coatings and a Ni-Al-Cr alloy. Surface and Coatings Technology, Elsevier, 2017, 309, pp.258-265. 10.1016/j.surfcoat.2016 Open Archive TOULOUSE Archive Ouverte (OATAO) OATAO is an open access repository that collects the work of Toulouse researchers and makes it freely available over the web where possible. Al and with Cr in such a way that Pt decreased their activities. According to the diffusion coefficient values, Pt had a greater influence on the Al activity than on the Cr one. Similarly, 2 μm of Pt and 3 μm of Pt-25Ir were deposited by electroplating on the same model alloy to investigate the effect of Ir. Heat treatments were performed in the same conditions as for Cr. Iridium slowed down the interdiffusion when compared with systems with Pt only. Iridium diffused slower toward the substrate than Pt and a lower Pt + Ir flux toward the substrate was found.As voids formed at the interdiffusion zone/substrate interface due to Kirkendall effect, this lower inward Pt + Ir flux resulted in a lower outward vacancy flux and then Ir reduced Kirkendall voids formation. Moreover, Ir decreased the Pt effect on Al activity by dilution or even gave an opposite contribution to the Pt one. This reduced the uphill diffusion of Al, delaying the α-NiPtAl phase formation. Diffusion paths of each model system were also identified after 15 min at 1100°C and all highlighted the α-NiPtAl phase formation and its aptitude to be used in TBC systems.

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Microstructure degradation of simple, Pt- and Pt+Pd-modified aluminide coatings on CMSX-4 superalloy under cyclic oxidation conditions

Cited by 32 publications

References 25 publications

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

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

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

Chromium and iridium effects on the short-term interdiffusion behaviour between Pt rich γ-γ′ bond-coatings and a Ni-Al-Cr alloy

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