scholarly journals Effect of Hf Additions to Pt Aluminide Bond Coats on EB-PVD TBC Life

2013 ◽  
pp. 77-92
Author(s):  
James Nesbitt ◽  
Ben Nagaraj ◽  
Jeffrey Williams
Keyword(s):  
Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4214
Author(s):  
Kranthi Kumar Maniam ◽  
Shiladitya Paul

The increased demand for high performance gas turbine engines has resulted in a continuous search for new base materials and coatings. With the significant developments in nickel-based superalloys, the quest for developments related to thermal barrier coating (TBC) systems is increasing rapidly and is considered a key area of research. Of key importance are the processing routes that can provide the required coating properties when applied on engine components with complex shapes, such as turbine vanes, blades, etc. Despite significant research and development in the coating systems, the scope of electrodeposition as a potential alternative to the conventional methods of producing bond coats has only been realised to a limited extent. Additionally, their effectiveness in prolonging the alloys’ lifetime is not well understood. This review summarises the work on electrodeposition as a coating development method for application in high temperature alloys for gas turbine engines and discusses the progress in the coatings that combine electrodeposition and other processes to achieve desired bond coats. The overall aim of this review is to emphasise the role of electrodeposition as a potential cost-effective alternative to produce bond coats. Besides, the developments in the electrodeposition of aluminium from ionic liquids for potential applications in gas turbines and the nuclear sector, as well as cost considerations and future challenges, are reviewed with the crucial raw materials’ current and future savings scenarios in mind.


Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 692 ◽  
Author(s):  
Sven Giese ◽  
Steffen Neumeier ◽  
Jan Bergholz ◽  
Dmitry Naumenko ◽  
Willem J. Quadakkers ◽  
...  

The mechanical properties of low-pressure plasma sprayed (LPPS) MCrAlY (M = Ni, Co) bond coats, Amdry 386, Amdry 9954 and oxide dispersion strengthened (ODS) Amdry 9954 (named Amdry 9954 + ODS) were investigated after annealing in three atmospheres: Ar–O2, Ar–H2O, and Ar–H2–H2O. Freestanding bond coats were investigated to avoid any influence from the substrate. Miniaturized cylindrical tensile specimens were produced by a special grinding process and then tested in a thermomechanical analyzer (TMA) within a temperature range of 900–950 °C. Grain size and phase fraction of all bond coats were investigated by EBSD before testing and no difference in microstructure was revealed due to annealing in various atmospheres. The influence of annealing in different atmospheres on the creep strength was not very pronounced for the Co-based bond coats Amdry 9954 and Amdry 9954 + ODS in the tested conditions. The ODS bond coats revealed significantly higher creep strength but a lower strain to failure than the ODS-free Amdry 9954. The Ni-based bond coat Amdry 386 showed higher creep strength than Amdry 9954 due to the higher fraction of the β-NiAl phase. Additionally, its creep properties at 900 °C were much more affected by annealing in different atmospheres. The bond coat Amdry 386 annealed in an Ar–H2O atmosphere showed a significantly lower creep rate than the bond coat annealed in Ar–O2 and Ar–H2–H2O atmospheres.


2015 ◽  
Vol 622 ◽  
pp. 394-401 ◽  
Author(s):  
V. Crespo ◽  
I.G. Cano ◽  
S. Dosta ◽  
J.M. Guilemany

2021 ◽  
pp. 109781
Author(s):  
Qing-Long Xu ◽  
Kang-Cheng Liu ◽  
Ke-Yan Wang ◽  
Li-Yan Lou ◽  
Yu Zhang ◽  
...  

2021 ◽  
Vol 1035 ◽  
pp. 584-590
Author(s):  
Kang Yuan ◽  
Zhao Ran Zheng

MCrAlY can be used as bond coats for thermal barrier coatings (TBCs) with good ductility and excellent resistance against high temperature oxidation and hot corrosion. The behavior of the microstructure development in the MCrAlY coatings plays a key role on the oxidation resistance. In this paper, the microstructure in the coatings oxidized at 750~1100 °C was analyzed. The formation of the phases and their fraction were studied by comparing thermodynamic simulation results with the experimental observations. At higher temperatures (>1000 °C) β-to-γ’-to-γ phase transformation took place while at lower temperatures (<1000 °C) β phase would transfer to γ directly. The results show that the simulation can semi-quantitatively predict the microstructure formed in the coating.


2021 ◽  
Vol 320 ◽  
pp. 31-36
Author(s):  
Marek Góral ◽  
Tadeusz Kubaszek ◽  
Barbara Kościelniak ◽  
Marcin Drajewicz ◽  
Mateusz Gajewski

Thermal barrier coatings are widely used for protection of gas turbine parts against high temperature oxidation and hot corrosion. In present work the microstructural assessment of TBCs produced by atmospheric plasma spray (APS) method was conducted. Three types of ceramic powders were used: magnesia- stabilized zirconia oxide (Metco 210), yttria stabilized zirconia oxide (YSZ -Metco 204) and fine-grained YSZ – Metco 6700. As a base material the Inconel 713 was used as well and CoNiCrAlY was plasma sprayed (APS) as a bond coat. The thickness of all ceramic layers was in range 80 – 110 μm. The elemental mapping of cross-section of magnesia-stabilized zirconia showed the presence of Mg, Zr and O in outer layer. In the YSZ ceramic layer the Y, Zr and O were observed during elemental mapping. The isothermal oxidation test was conducted at 1100 °C for 500 h in static laboratory air. On all samples the delamination and spallation of ceramic layers was observed. Chemical composition analysis of coatings showed the presence of two areas: the first one contained elements from bond coats: Ni, Cr, Al, Co and second area contained O, Cr Co and O that suggest the scale formation. The obtained results showed the total degradation of all ceramic layers as a result of internal stresses in bond-coat. Microscopic analysis showed the areas with complete degradation of bond coats and formation of thick oxides layer.


Coatings ◽  
2010 ◽  
Vol 1 (1) ◽  
pp. 3-16 ◽  
Author(s):  
Alessio Fossati ◽  
Martina Di Ferdinando ◽  
Alessandro Lavacchi ◽  
Andrea Scrivani ◽  
Carlo Giolli ◽  
...  

2012 ◽  
pp. 93-102 ◽  
Author(s):  
Ralf Webler ◽  
Markus Krottenthaler ◽  
Steffen Neumeier ◽  
Karsten Durst ◽  
Mathias Göken

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