scholarly journals The new concept of thermal barrier coatings with Pt + Pd/Zr/Hf-modified aluminide bond coat and ceramic layer formed by PS-PVD method

2021 ◽  
Vol 40 (1) ◽  
pp. 281-286 ◽  
Author(s):  
Marek Góral ◽  
Maciej Pytel ◽  
Tadeusz Kubaszek ◽  
Marcin Drajewicz ◽  
Wojciech Simka ◽  
...  
Keyword(s):  
Thermal Barrier Coatings ◽  
Bond Coat ◽  
Vapour Deposition ◽  
Aluminide Coating ◽  
Nickel Superalloy ◽  
Ceramic Layer ◽  
Attractive Alternative ◽  
Thermal Barrier ◽  
Physical Vapour Deposition ◽  
Barrier Coatings

Abstract Thermal barrier coatings (TBCs) are widely used for protection of gas turbine parts from high temperature and corrosion. In the present study, the new concept of TBCs with three-element-modified aluminide coatings was presented. In the first stage, the Pt and Pd were electroplated on MAR M247 nickel superalloy. In the next stage, the low-activity CVD aluminizing process with Zr or Hf doping was conducted. The ceramic layer containing yttria-stabilized zirconia was obtained by the plasma spray physical vapour deposition (PS-PVD) method. The microscopic examination showed the formation of aluminide coating containing up to 5 at% of Pt and 10 at% of Pd in (Ni, Pt, Pd)Al solid solution. The small concentration of Hf and Zr in diffusion zone of aluminide bond coat was noted as well. The outer ceramic layer was characterized by columnar structure typically formed during the PS-PVD process. The obtained results showed that the new concept of TBCs formed using new processes might be an attractive alternative to conventional coatings produced using the expensive electron beam physical vapour deposition (EB-PVD) method.

Microstructure of Thermal Barrier Coatings Deposited by Low Pressure Plasma Spraying and Chemical Vapour Deposition Methods on Rene 80 Nickel Superalloy

2015 ◽  
Vol 227 ◽  
pp. 333-336
Author(s):  
Marek Góral ◽  
Maciej Pytel ◽  
Wojciech Cmela ◽  
Sławomir Kotowski
Keyword(s):  
Plasma Spraying ◽  
Thermal Barrier Coatings ◽  
Hot Corrosion ◽  
Vapour Deposition ◽  
Nickel Superalloy ◽  
Ceramic Layer ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Low Pressure Plasma ◽  
Low Pressure Plasma Spraying

The paper presents results of research into thermal barrier coatings characterized by high oxidation resistance and hot corrosion. Bondcoats were formed by overaluminizing of an MeCrAlY–type coating deposited by low pressure plasma spraying. The outer ceramic layer of yttrium oxide stabilized zirconia oxide (Metco 6700) was deposited by plasma spray physical vapour deposition (PS-PVD). For comparison purposes additionally LPPS-sprayed were MeCrAlY bondcoats, which were not subsequently aluminized. Used as base material was Rene 80 nickel superalloy. The research has shown that as a result of aluminizing by the CVD method there was formed in the bondcoat a deposit zone built of the β-NiAl phase which protects from oxidation. Preserved below increased chromium content ensures resistance to hot corrosion. The outer ceramic layer was characterized by columnar structure similar to that obtained in the EB-PVD process.

Microstructure and Oxidation Resistance of Thermal Barrier Coatings with Different Ceramic Layer

2021 ◽  
Vol 320 ◽  
pp. 31-36
Author(s):  
Marek Góral ◽  
Tadeusz Kubaszek ◽  
Barbara Kościelniak ◽  
Marcin Drajewicz ◽  
Mateusz Gajewski
Keyword(s):  
Thermal Barrier Coatings ◽  
Bond Coat ◽  
Ceramic Layer ◽  
Thermal Barrier ◽  
Elemental Mapping ◽  
Stabilized Zirconia ◽  
Barrier Coatings ◽  
Bond Coats ◽  
All Ceramic ◽  
Zirconia Oxide

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.

Emittance of Y2O3 stabilised ZrO2 thermal barrier coatings prepared by electron-beam physical-vapour deposition

2000 ◽  
Vol 32 (3) ◽  
pp. 361-368 ◽  
Author(s):  
Jochen Manara ◽  
Rainer Brandt ◽  
Joachim Kuhn ◽  
Jochen Fricke ◽  
Thomas Krell ◽  
...  
Keyword(s):  
Electron Beam ◽  
Thermal Barrier Coatings ◽  
Vapour Deposition ◽  
Thermal Barrier ◽  
Physical Vapour Deposition ◽  
Barrier Coatings

Thermal Barrier Coating Deposited Using the PS-PVD Method on TiAl-Nb-Mo Intermetallic Alloy with Different Types of Bond Coats

2021 ◽  
Vol 320 ◽  
pp. 60-65
Author(s):  
Marek Góral ◽  
Tadeusz Kubaszek ◽  
Marcin Kobylarz ◽  
Marcin Drajewicz ◽  
Maciej Pytel
Keyword(s):  
Bond Coat ◽  
Vapour Deposition ◽  
Columnar Structure ◽  
Intermetallic Alloy ◽  
Ceramic Layer ◽  
Thermal Barrier ◽  
Physical Vapour Deposition ◽  
Bond Coats ◽  
Tial Intermetallics ◽  
Different Types

TiAl intermetallics can be considered an alternative for conventional nickel superalloys in the high-temperature application. A TBC (Thermal Barrier Coatings) with ceramic topcoat with columnar structure obtained using EB-PVD (electron beam physical vapour deposition) is currently used to protect TiAl intermetallics. This article presents the new concept and technology of TBC for TiAl intermetallic alloys. Bond coats produced using the slurry method were obtained. Si and Al nanopowders (70 nm) were used for water-based slurry preparation with different composition of solid fraction: 100 wt.% of Al, 50 wt.% Al + 50 wt.% Si and pure Si. Samples of TNM-B1 (TiAl-Nb-Mo) TiAl intermetallic alloy were used as a base material. The samples were immersed in slurries and dried. The samples were heat treated in Ar atmosphere at 1000 °C for 4 h. The outer ceramic layer was produced using the new plasma spray physical vapour deposition (PS-PVD) method. The approximately 110 μm thick outer ceramic layers contained yttria-stabilised zirconium oxide. It was characterised by a columnar structure. Differences in phase composition and structures were observed in bond coats. The coatings obtained from Al-contained slurry were approximately 30 μm thick and consisted of two zones: the outer contained the TiAl3 phase and the inner zone consisted of the TiAl2 phase. The second bond coat produced from 50 wt.% Al + 50 wt.% Si slurry was characterised by a similar thickness and contained the TiAl2 phase, as well as titanium silicides. The bond coat formed from pure-Si slurry had a thickness < 10 μm and contained up to 20 at % of Si. This suggests the formation of different types of titanium silicides and Ti-Al phases. The obtained results showed that PS-PVD method can be considered as an alternative to the EB-PVD method, which is currently applied for deposition a columnar structure ceramic layer. On the other hand, the use of nanopowder for slurry production is problematic due to the smaller thickness of the produced coating in comparison with conventional micro-sized slurries.

Solid particle erosion of thermal spray and physical vapour deposition thermal barrier coatings

Wear ◽  
2011 ◽  
Vol 271 (11-12) ◽  
pp. 2909-2918 ◽  
Author(s):  
F. Cernuschi ◽  
L. Lorenzoni ◽  
S. Capelli ◽  
C. Guardamagna ◽  
M. Karger ◽  
...  
Keyword(s):  
Thermal Spray ◽  
Solid Particle ◽  
Thermal Barrier Coatings ◽  
Vapour Deposition ◽  
Thermal Barrier ◽  
Solid Particle Erosion ◽  
Physical Vapour Deposition ◽  
Particle Erosion ◽  
Barrier Coatings

scholarly journals Modelling evaporation in electron-beam physical vapour deposition of thermal barrier coatings

2021 ◽  
Author(s):  
Julie Chevallier ◽  
Luis Isern ◽  
Koldo Almandoz Forcen ◽  
Christine Chalk ◽  
John R. Nicholls
Keyword(s):  
Electron Beam ◽  
Thermal Barrier Coatings ◽  
Computational Models ◽  
Evaporation Rate ◽  
Vapour Deposition ◽  
Thermal Barrier ◽  
Physical Vapour Deposition ◽  
Local Composition ◽  
Barrier Coatings ◽  
Compositional Segregation

AbstractThis work presents computational models of ingot evaporation for electron-beam physical vapour deposition (EB-PVD) that can be applied to the deposition and development of thermal barrier coatings (TBCs). TBCs are insulating coatings that protect aero-engine components from high temperatures, which can be above the component’s melting point. The development of advanced TBCs is fuelled by the need to improve engine efficiency by increasing the engine operating temperature. Rare-earth zirconates (REZ) have been proposed as the next-generation TBCs due to their low coefficient of thermal conductivity and resistance to molten calcium-magnesium alumina-silicates (CMAS). However, the evaporation of REZ has proven to be challenging, with some coatings displaying compositional segregation across their thickness. The computational models form part of a larger analytical model that spans the whole EB-PVD process. The computational models focus on ingot evaporation, have been implemented in MATLAB and include data from 6 oxides: ZrO2, Y2O3, Gd2O3, Er2O3, La2O3 and Yb2O3. Two models (2D and 3D) successfully evaluate the evaporation rates of constituent oxides from multiple-REZ ingots, which can be used to highlight incompatibilities and preferential evaporation of some of these oxides. A third model (local composition activated, LCA) successfully predicts the evaporation rate of the whole ingot and replicates the cyclic change in composition of the evaporated plume, which is manifested as changes in compositional segregation across the coating’s thickness. The models have been validated with experimental data from Cranfield University’s EB-PVD coaters, published vapour pressure calculations and evaporation rate formulas described in the literature.

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