Investigation of the formation of an amorphous film at the ZrO2Y2O3/NiCoCrAlY interface of thermal barrier coatings produced by plasma spraying

Bartuli, Cecilia; Bertamini, L.; Matera, Susanna; Sturlese, S.

doi:10.1016/0921-5093(94)09697-x

Cited by 19 publications

(10 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It can be seen that the ZrO 2 coating is mainly composed of a large amount of monoclinic phase (m-ZrO 2 ) and a small amount of tetragonal phase (t-ZrO 2 ), along with the Y doping. The monoclinic phase in the ZrO 2 coatings gradually disappeared, and the coatings mainly contained Y-doped t-ZrO 2 (t-Zr 1−x Y x O 2−0.5x , 0 < x < 1) and a small amount of t-ZrO 2 [ 40 ], which indirectly proves the successful doping of the Y element.…”

Section: Resultsmentioning

confidence: 99%

Yttria-Stabilized Zirconia Composite Coating as Barrier to Reduce Hydrogen Permeation into Steel

Wu,

Xie,

et al. 2024

Materials

View full text Add to dashboard Cite

Hydrogen atoms can enter into metallic materials through penetration and diffusion, leading to the degradation of the mechanical properties of the materials, and the application of hydrogen barrier coatings is an effective means to alleviate this problem. Zirconia coatings (ZrO2) have been widely studied as a common hydrogen barrier coating, but zirconia undergoes a crystalline transition with temperature change, which can lead to volumetric changes in the coating and thus cause problems such as cracking and peeling of the coating. In this work, ZrO2 coating was prepared on a Q235 matrix using a sol-gel method, while yttria-stabilized zirconia (YSZ) coatings with different contents of rare earth elements were prepared in order to alleviate a series of problems caused by the crystal form transformation of ZrO2. The coating performances were evaluated by the electrochemical hydrogen penetration test, pencil hardness test, scratch test, and high-temperature oxidation test. The results show that yttrium can improve the stability of the high-temperature phase of ZrO2, alleviating the cracking problem of the coating due to the volume change triggered by the crystalline transition; improve the consistency of the coating; and refine the grain size of the oxide. The performance of YSZ coating was strongly influenced by the yttria doping mass, and the coating with 10 wt% yttria doping had the best hydrogen barrier performance, the best antioxidant performance, and the largest adhesion. Compared with the matrix, the steady-state hydrogen current density of the YSZ coating decreased by 72.3%, the antioxidant performance was improved by 65.8%, and the ZrO2 coating hardness and adhesion levels were B and 4B, respectively, while YSZ coating hardness and adhesion were upgraded to 2H and 5B. With the further increase in yttrium doping mass, the hardness of the coating continued to improve, but the defects of the coating increased, resulting in a decrease in the hydrogen barrier performance, antioxidant performance, and adhesion. In this work, the various performances of ZrO2 coating were significantly improved by doping with the rare earth element, which provides a reference for further development and application of oxide coatings.

show abstract

Section: Resultsmentioning

confidence: 99%

Yttria-Stabilized Zirconia Composite Coating as Barrier to Reduce Hydrogen Permeation into Steel

Wu,

Xie,

et al. 2024

Materials

View full text Add to dashboard Cite

show abstract

“…The temperature at the interface between the coating and the substrate was likely to be higher for the C2 blades, imparting an increased possibility of interface reactions between the in situ layer and the underlying TGO or metallic substrate. This type of reaction should have increased the adhesion strength of the in situ layers to the substrate [7]. As was mentioned in our previous study [5], reactions, like the conversion reaction between the incoming silica and aluminum in the bulk (SiO 2 + Al = Al 2 O 3 + Si), or simple admixing between SiO 2 and Al 2 O 3 to yield mullite, made the in situ coating more stubborn to chipping or delamination.…”

Section: Ex Situ Oxidation Of In713 Turbine Blades In Situ Deposited mentioning

confidence: 93%

Ex situ oxidation of IN713 turbine blades in situ deposited with silica layers during operation of a micro-gas turbine

Kim

2011

Met. Mater. Int.

View full text Add to dashboard Cite

The long-term stability of silica layers deposited in situ on the IN713 turbine blades was investigated by surveying an ex situ thermally cycled oxidation test in air at 1050°C. Two types of in situ coatings were prepared by burning tetraethylorthosilicate with fuel during a 100-min operation of a 13 kgf-class gas turbine. The degradation of the blades upon the oxidation test was evaluated by monitoring the weight change and by analyzing the microscopic evolution of surface oxides. One coating, characterized by a uniform and relatively thick porous coating on the pressure side, was chipped off in the early stages of the test. The other coating was ~4 µm thick at the region near the root, but was too thin (and transparent) at the other parts of the blade to be rendered as protective one. However, this coating was found to be more stable towards chipping than the other coating during the oxidation test. The stability of the coatings was examined in terms of the interaction between the deposited layer and the underlying thermally grown oxide or substrate during the operation of the gas turbine.

show abstract

“…Studies of TBC systems have shown that an amorphous film at the interface between the coating and the substrate of thermal barrier coatings is produced by plasma spraying. 15 Therefore this amorphous layer must be considered in the model. A standard TBC specimen sized model can then be used to generate results specifically for application to TBC specimens, with indentation by a rigid indenter with a rounded tip identical to that of an actual Brale indenter.…”

Section: Modelmentioning

confidence: 99%

Role of impact on determination of interfacial toughness measurement by indentation for thermal barrier coating systems

Eki̇ci̇¹

2005

Surface Engineering

View full text Add to dashboard Cite

The measurement of interfacial toughness by an indentation method was proposed several years ago. It has been shown that this method is very simple and reliable for the calculation of interfacial toughness. For this reason, many studies were performed for different substrate and coating combinations. Numerical models also supported these studies. Unfortunately, the success of this method depends on the hardness of the substrate. In most studies, the coating was ceramic and the substrate was steel. The substrate must be hard enough to get a circular crack around the indentation zone. If the substrate is not hard enough, the circular crack cannot be seen. In the light of the experiments performed for different combinations of substrate and coating, the use of the method was restricted to a very narrow range of materials that are mainly used for thermal barrier coating systems. In the present study, this method is used even for a medium hardness substrate. In order to get a circular crack, loading is performed with constant acceleration instead of static loading. The success of the method is shown to be considerably increased. List of symbolsEBPVD electron beam physical vapour deposition G energy release rate D damage parameter K c interfacial fracture toughness s stress e r radial strain e strain rate e h circumferential strain e p effective plastic strain : e Ã effective plastic strain rate e f fracture strain V Poisson's ratio U radial displacement R radial position D depth of indentation A projected indentation in radial direction DT change in temperature DL change in length Dh depth of indentation V velocity of indenter a thermal expansion coefficient

show abstract

Investigation of the formation of an amorphous film at the ZrO2Y2O3/NiCoCrAlY interface of thermal barrier coatings produced by plasma spraying

Cited by 19 publications

References 17 publications

Yttria-Stabilized Zirconia Composite Coating as Barrier to Reduce Hydrogen Permeation into Steel

Yttria-Stabilized Zirconia Composite Coating as Barrier to Reduce Hydrogen Permeation into Steel

Ex situ oxidation of IN713 turbine blades in situ deposited with silica layers during operation of a micro-gas turbine

Role of impact on determination of interfacial toughness measurement by indentation for thermal barrier coating systems

Contact Info

Product

Resources

About