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Chevalier, S.; Dufour, P.; Bonnet, Gilles; Colson, J.C.

doi:10.1023/a:1018819800740

Cited by 16 publications

(9 citation statements)

References 24 publications

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“…For the two annealing temperatures, 700 and 800 C, the 18 O peaks present a single maximum, close to the metal-oxide interface. There is no more 18 O peak at the gas-oxide interface (in comparison with Fig. 8), which suggests that oxygen ion diffusion becomes predominant on the annealed materials.…”

Section: Marker Experimentsmentioning

confidence: 78%

“…On untreated Fe-20Cr-5Al specimens, SNMS results show that after the two-stage experiment most of the new oxide formed with 18 O is located at the external interface (Fig. 7).…”

Section: Marker Experimentsmentioning

confidence: 98%

“…10) but in the pre-grown oxide scale. The 18 O profile shows that the new oxide is generated inside the primarily formed scale by a mixed anionic and cationic diffusion process.…”

Section: Marker Experimentsmentioning

confidence: 98%

“…The limitations of coating application to improve the oxidation resistance of aluminaforming steels were previously described by Pint [3]. Nevertheless, the reasons why surface doping is inefficient in the case of alumina-forming steels, whereas they are beneficial to improve the oxidation resistance of chromia-forming alloys [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21], are still unclear.…”

Section: Introductionmentioning

confidence: 99%

“…This technique is very convenient to follow the appearance and transformation of transient alumina, as well as to identify the yttrium containing phases at high temperature [22][23][24]. The second technique consists in oxidising the alumina-forming steels under 16 O 2 followed by 18 O 2 and to locate 18 O in the alumina scales by using secondary neutral mass spectrometry (SNMS) or secondary ion mass spectrometry (SIMS). The location of the 18 O peaks allows to know if cation diffusion, anion diffusion or mixed diffusion process are responsible for the alumina scale growth mechanism.…”

Section: Introductionmentioning

confidence: 99%

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Influence of the mode of introduction of a reactive element on the high temperature oxidation behavior of an alumina-forming alloy. Part III: The use of two stage oxidation experiments and in situ X-ray diffraction to understand the oxidation mechanisms

Chevalier¹,

Issartel²,

Cueff³

et al. 2006

Materials and Corrosion

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International audienceThe aim of this work was to investigate several different yttrium introduction routes to improve the high temperature oxidation resistance of a Fe-20Cr-5Al model alloy. Y2O3 sol-gel coatings, Y2O3 metal-organic chemical vapor deposition (MOCVD) coatings, yttrium. ion implantation and yttrium as alloying element (0.1 wt.%) were the different methods of introduction of the reactive element. Both isothermal and cyclic oxidation tests showed that the surface introduction of yttrium or yttrium oxide did not drastically improve the oxidation behavior of the steel. Complementary experiments were performed to understand the lack of major beneficial effects of the so-treated samples. Two stage oxidation experiments under 200 mbar O-16(2) and O-18(2) followed by secondary neutral mass spectrometry (SNMS) were performed to understand the alumina scale growth mechanisms, according to the introduction route of the reactive element. The results exhibited that the yttrium induced an increase of the inward transport of oxygen through the alumina scale compared to the untreated specimen. Nevertheless, the outward transport of aluminum was generally observed, except for the specimen containing Y as alloying element, which exhibited only a single O-18 peak close to the metal/oxide interface. Phase transformations during the oxidation at 1100 degrees C were registered by in-situ X-ray diffraction (XRD). The untreated alloy was only covered by a thin layer of alpha-Al2O3. For implanted specimens, yttrium was incorporated in Y3Al5O12 and YAlO3 phases. All the YAlO3 is transformed into Y3Al5O12 after less than 10 h. For the MOCVD or the sol-gel coated samples, the primary formed YAlO3 phase was progressively transformed into Y3Al5O12. For the Fe-20Cr-5Al-0.1Y alloy, no yttrium containing phases could be detected, even after 40 h of oxidation test at 1100 degrees C

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Section: Marker Experimentsmentioning

confidence: 78%

“…On untreated Fe-20Cr-5Al specimens, SNMS results show that after the two-stage experiment most of the new oxide formed with 18 O is located at the external interface (Fig. 7).…”

Section: Marker Experimentsmentioning

confidence: 98%

“…10) but in the pre-grown oxide scale. The 18 O profile shows that the new oxide is generated inside the primarily formed scale by a mixed anionic and cationic diffusion process.…”

Section: Marker Experimentsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Influence of the mode of introduction of a reactive element on the high temperature oxidation behavior of an alumina-forming alloy. Part III: The use of two stage oxidation experiments and in situ X-ray diffraction to understand the oxidation mechanisms

Chevalier¹,

Issartel²,

Cueff³

et al. 2006

Materials and Corrosion

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Influence of the mode of introduction of a reactive element on the high temperature oxidation behavior of an alumina‐forming alloy. Part I: Isothermal oxidation tests

Chevalier¹,

Strehl²,

Buscail³

et al. 2004

Materials & Corrosion

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Different modes of introduction of yttrium have been tested with regard to the influence on the high temperature oxidation behavior of a FeCral alloy. Y2O3 sol‐gel coatings, Y2O3 metal‐organic chemical vapor deposition (MOCVD) coatings, implanted yttrium ions and yttrium as alloying element (0.1 wt.%) in the same Fe‐20Cr‐5Al alloy were oxidized at 1100°C in air under atmospheric pressure. Whatever the mode of introduction of the reactive element, the oxidation rates were not decreased compared to the oxidation rate of the blank specimen. The observation of the oxidized surface indicated that the alumina scale largely spalled from the blank alloy. Spallation was reduced for the Y2O3 sol‐gel coated, the Y2O3 MOCVD coated alloys and the yttrium ion implanted steels. The Y‐containing alloy did not exhibit any detachment of the oxide scale, indicating the best high temperature oxidation behavior, at least from the viewpoint of scale adherence.

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Metallic interconnects for solid oxide fuel cell: Performance of reactive element oxide coating during long time exposure

Fontana

Chevalier

Caboche

2011

Materials & Corrosion

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One of challenges in improving the performance and cost-effectiveness of SOFCs (solid oxide fuel cells) is the development of suitable interconnects materials. Chromia-forming alloys and especially ferritic stainless steels, like Crofer22APU, are considered to be among the most promising candidate materials as interconnects in SOFC stacks. However, the performance of chromia-forming materials can be limited by the low electronic conductivity of the oxide scale (high ASR -area specific resistance -value). Such degradation are unacceptable regarding the long-term operation (>40 000 h). A previous study [1] demonstrated that in air, the addition of a nanometric reactive element oxide (La 2 O 3 ) layer applied by metal organic chemical vapor deposition (MOCVD) drastically improved both corrosion rate and electrical properties of Crofer22APU and Haynes230 alloys for 100 h at 800 8C. In this present study coating performances were checked after 10 months (7500 h) and 20 months (15 000 h) at 800 8C in air. The corrosion products were carefully analyzed by SEM, EDX, and XRD. ASR measurements are realized after long time exposure. This study demonstrates that the Crofer22APU alloy has a good oxidation resistance after 15 000 h in air but this alloy has an ASR value equal to 0.370 V cm 2 . The coatings composed of a thin reactive element oxide such as La 2 O 3 resulted in an important improvement in the high temperature oxidation resistance; the ASR values are equal to 0.154 V cm 2 . Haynes230 alloy has a better oxidation resistance but the formation of an insulating Al 2 O 3 /SiO 2 layer could be detrimental.

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Untitled

Cited by 16 publications

References 24 publications

Influence of the mode of introduction of a reactive element on the high temperature oxidation behavior of an alumina-forming alloy. Part III: The use of two stage oxidation experiments and in situ X-ray diffraction to understand the oxidation mechanisms

Influence of the mode of introduction of a reactive element on the high temperature oxidation behavior of an alumina-forming alloy. Part III: The use of two stage oxidation experiments and in situ X-ray diffraction to understand the oxidation mechanisms

Influence of the mode of introduction of a reactive element on the high temperature oxidation behavior of an alumina‐forming alloy. Part I: Isothermal oxidation tests

Metallic interconnects for solid oxide fuel cell: Performance of reactive element oxide coating during long time exposure

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