Aluminide Coating Formation on Internal Passages of GTD-111 Superalloy by Slurry Technique

2008 ◽  
Vol 595-598 ◽  
pp. 185-190 ◽  
Author(s):  
K. Shirvani ◽  
Amir Firouzi
Keyword(s):  
High Temperature ◽  
Aluminide Coating ◽  
Air Cooling ◽  
Diffusion Coatings ◽  
Aluminide Coatings ◽  
Internal Surfaces ◽  
Nial Phase ◽  
The Matrix ◽  
Coating Formation ◽  
Cooled Blade

The diffusion aluminide coatings are widely used in the air-cooling passages to protect their surfaces against high temperature corrosion. In this study plain and Si-modified aluminide coatings were applied by slurry technique on internal surfaces of Ni-base GTD-111 superalloy cylindrical specimens derived from a gas turbine air-cooled blade. The slurries containing Al or Al plus Si powders were applied on internal surfaces by injection method. Then, the samples were heated to high temperature (800-1000°C) to form the coatings. Optical, SEM-EDS, and XRD were utilized for characterizing microstructures and phase compositions of the coatings. The thicknesses of applied coatings on internal surfaces were in the range of 30-50 μm that meets specifications for diffusion coatings in such application (i.e. 25-756m). The examinations demonstrated that both coating types were contained β-NiAl phase as the matrix. The uniformities of coatings applied on different surface positions of passageway were determined. In addition, the effects of time and temperature of coating process as well as mass of dried slurry on the coating thickness were also discussed.

Effect of diffusion coatings on the high temperature properties of nickel-chromium-superalloys

2018 ◽  
Vol 32 (19) ◽  
pp. 1840056 ◽  
Author(s):  
Byeong Woo Lee
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Aluminide Coating ◽  
Pure Aluminum ◽  
Protective Layer ◽  
Nitrogen Atmosphere ◽  
Silicide Coating ◽  
Diffusion Coatings ◽  
Aluminide Coatings ◽  
Negative Role

The halide-activated pack cementation method was utilized to deposit aluminide or silicide coatings on Inconel 617 and Hastelloy X superalloys. Aluminide and silicide diffusion coatings were formed at 850[Formula: see text]C for 2 h in nitrogen atmosphere, using a pack mixture containing pure aluminum (Al) or silicon (Si) and aluminum oxide (Al2O3) powders with activators of NH4Cl and AlF3. Aluminide-coated alloys showed homogeneous and uniform microstructures. Al diffused into the alloy inwards and aluminide diffusion coatings of [Formula: see text]17 [Formula: see text]m thick were formed inside the alloy. It was shown that the Al coatings played a key role in blocking off the excessive corrosion products at a high temperature for the alloys. The enhanced thermal stability and improved wear resistance were achieved in the aluminide coatings. In contrast to the aluminide coating, the silicide coating played a negative role, unable to provide the protective layer. The microstructural evolution and thermal stability of the aluminide- and silicide-coated alloys have been elucidated.

The Influence of Long-Term Heat Treatment on Microstructure of Zr-Modified Aluminide Coating Deposited by CVD Method on MAR M200+Hf Nickel Superalloy

2013 ◽  
Vol 592-593 ◽  
pp. 469-472 ◽  
Author(s):  
Ryszard Filip ◽  
Marek Góral ◽  
Marcin Zawadzki ◽  
Andrzej Nowotnik ◽  
Maciej Pytel
Keyword(s):  
Heat Treatment ◽  
Aluminide Coating ◽  
Chemical Vapour ◽  
Nickel Superalloy ◽  
Phase Changes ◽  
Vacuum Furnace ◽  
Aluminide Coatings ◽  
Nial Phase ◽  
Main Component

The article presents the investigation of influence of long-term annealing of Zr modified aluminide coatings on its microstructure. The coatings were deposited by Chemical Vapour Deposition on MAR M200+Hf nickel superalloy. Annealing was carried out in a vacuum furnace at the temperature 1020°C within the period of 12, 16 and 20 hours respectively. The microstructral analysis was carried out using Hitachi S-3400 scanning electron microscope. Phase changes in the aluminide layer were observed, particularly the NiAl phase into Ni3Al. Changes in thickness of individual layers in the coating were observed. Conducted research showed that there is no influence of Zr on structure of the aluminide coating during annealing. The structure changes are similar to observed in simple aluminide coating. The maximum time of heat treatment without significant influence on structure of aluminide coating is 16 hours. After that time the main component of coating is NiAl phase.

Effect of Hf Addition on High Temperature Properties of Ir-Containing Alloy Coatings

2007 ◽  
Vol 546-549 ◽  
pp. 1689-1694 ◽  
Author(s):  
Hideyuki Murakami ◽  
K. Kamiya ◽  
Akihiro Yamaguchi ◽  
Ying Na Wu ◽  
Seiji Kuroda
Keyword(s):  
High Temperature ◽  
Cyclic Oxidation ◽  
Flat Surface ◽  
Small Difference ◽  
Aluminide Coating ◽  
High Temperature Properties ◽  
Aluminide Coatings ◽  
Cyclic Oxidation Test ◽  
Hf Addition ◽  
Pack Cementation Process

In the present study, high temperature properties of Ir-modified and Ir-Hf-modified aluminide coatings on Ni-based single crystal superalloy TMS-82+ were discussed. They were prepared by depositing pure Ir and Ir-Hf alloys on TMS-82+ using magnetron sputtering and EB-PVD, followed by a conventional Al-pack cementation process. The effects of Hf addition on the oxidation resistance and top-coat spallation resistance were investigated. Cyclic oxidation test at 1423K for 1h as one heating cycle revealed that while there is a small difference in oxidation kinetics and spallation lives between Ir and Ir-Hf coatings, drastic difference in surface morphology was observed. After 50 oxidation cycles the Ir-modified aluminide coating showed surface rumpling whereas the Ir-Hf modified aluminide coatings kept the flat surface. It was also revealed that excessive addition of Hf promoted the internal oxidation, resulting in the deterioration of substrates. These results agree with the conventional Pt-modified aluminide coatings and Ni-Al-Hf alloys.

The Oxidation Resistance of Nonmodified and Zr-Modified Aluminide Coatings Deposited by the CVD Method

2015 ◽  
Vol 227 ◽  
pp. 361-364
Author(s):  
Ryszard Filip ◽  
Maryana Zagula-Yavorska ◽  
Maciej Pytel ◽  
Jolanta Romanowska ◽  
Mateusz Maliniak ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Oxidation Resistance ◽  
Protective Coating ◽  
Aluminide Coating ◽  
Nickel Superalloy ◽  
Cvd Method ◽  
Aluminide Coatings ◽  
Eds Analysis ◽  
Nial Phase

The aim of the present work was to determine the influence of chemical composition of the protective coating on the oxidation resistance of the protected alloy. Zirconium modified and nonmodified aluminide coatings were deposited on the MAR M200 nickel superalloy by the CVD method. The oxidation tests were conducted at 1100°C into 23 hour in the air. The chemical composition (EDS) analysis was performed. The kinetic of oxidation of zirconium modified and nonmodified aluminide coatings was similar. Oxides inclusions called pegs were observed on the surface of oxidized aluminide coating. HfO2 oxide is more stable than Al2O3 oxide, hafnium atoms can replace aluminum atoms in Al2O3 oxides. This phenomena let to stabilize NiAl phase and increase of oxidation resistance of aluminide coating.

A Low Temperature CVD Process for Aluminum and Aluminide Coatings

2000 ◽  
Author(s):  
J. Liburdi ◽  
P. Lowden ◽  
V. Moravek
Keyword(s):  
Low Temperature ◽  
Aluminide Coating ◽  
Pure Aluminum ◽  
Turbine Blades ◽  
Chemical Vapour ◽  
Thin Layers ◽  
Internal Diameter ◽  
Temperature Oxidation ◽  
Aluminide Coatings ◽  
Internal Surfaces

A novel, low temperature Organometallic Chemical Vapour process (LOM), developed by Liburdi Engineering is presented in this paper. The process, which is widely used in the electronics industry to apply thin layers of pure aluminum, has been successfully scaled from a 3″ (75 mm) diameter quartz reactor to a production hot wall metal retort with an internal diameter of 18″ (0.45m) and a height of 60″ (1.5m). The capability for simultaneously coating external and internal surfaces is discussed. The aluminum layer can be used directly for low temperature atmospheric corrosion protection in place of IVADIZING or diffusion heat treated to produce an oxidation resistant aluminide coating for superalloys. Results of cyclic oxidation and salt fog corrosion testing are presented. The potential for alloying with modifying elements such as platinum to further enhance its high temperature oxidation resistance and to use the process in conjunction with thermal barrier coatings are presented. Potential applications ranging from coating of heat exchangers and automotive catalytic converters to the coating of industrial and aero turbine blades with complex cooling passages are presented.

Elaboration of Nickel Aluminide Diffusion Coatings: Application to Oxidation Resistance

2008 ◽  
Vol 595-598 ◽  
pp. 41-49 ◽  
Author(s):  
Céline Choux ◽  
Sébastien Chevalier ◽  
Yannik Cadoret
Keyword(s):  
High Temperature ◽  
Nickel Aluminide ◽  
Diffusion Mechanism ◽  
Alumina Scale ◽  
Organic Chemical ◽  
Material Surface ◽  
Protective Oxide ◽  
Diffusion Coatings ◽  
Aluminide Coatings ◽  
Α Al2o3

Aluminide diffusion coatings are widely used in aeronautic domain. Nickel based superalloys present good mechanical properties and creep resistance at high temperature but their corrosion resistance is somewhat poor. In order to enhance their lifetime at high temperature, aluminide coatings can be applied on alloy surface. Aluminium present on material surface can form, at high temperature, alumina scale which is a protective oxide scale. In the present study, nickel aluminide coatings were carried out by aluminisation in a single step pack cementation process on nickel based superalloys 600 and AM1. Ni-Al intermetallic was obtained in each case. Oxidation tests were carried out at 900°C in air under atmospheric pressure. At this temperature, transient alumina as γ-Al2O3 and θ-Al2O3 appear on surface and are less protective than the stable α- Al2O3. Reactive elements can enhance α-Al2O3 nucleation and change diffusion mechanism during oxidation leading to a better adherence of alumina scale. In the present work, yttria was introduced by Metal-Organic Chemical Vapour Deposition (MOCVD) prior to the aluminisation. Yttria doped and undoped sample behaviours were compared under oxidising atmospheres.

scholarly journals Diffusion-Controlled Growth and Microstructural Evolution of Aluminide Coatings on Superalloys and Steel

2017 ◽  
Vol 13 ◽  
pp. 167-195 ◽  
Author(s):  
Aloke Paul
Keyword(s):  
Microstructural Evolution ◽  
Aluminide Coating ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Controlled Growth ◽  
Aluminide Coatings ◽  
Diffusion Analysis ◽  
Nial Phase ◽  
Diffusion Controlled ◽  
Diffusion Rates

The diffusion-controlled growth and microstructural evolution at the interface of aluminide coatings and different substrates such as Ni-base superalloys and steel are reviewed. Quantitative diffusion analysis indicates that the diffusion rates of components in the β-NiAl phase increases with the addition of Pt. This directly reflects on the growth rate of the interdiffusion zone. The thickness and formation of precipitates increase significantly with the Pt addition. Mainly Fe2Al5phase grows during hot dip aluminization of steel along with few other phases with the very thin layer. Chemical vapor deposition process is being established for a better control of the composition of the Fe-aluminide coating on steel.

scholarly journals Oxidation Resistance of Modified Aluminide Coatings

2019 ◽  
Vol 253 ◽  
pp. 03006
Author(s):  
Jolanta Romanowska ◽  
Maryana Zagula-Yavorska ◽  
Łukasz Kolek
Keyword(s):  
Beneficial Effect ◽  
Oxidation Resistance ◽  
Noble Metals ◽  
Aluminide Coating ◽  
Pure Nickel ◽  
Scale Growth ◽  
Aluminide Coatings ◽  
Cyclic Oxidation Test ◽  
Nial Phase ◽  
Better Than

The application of protective aluminide coatings is an effective way to increase the oxidation resistance of the treated parts and prolongs their lifetime. The addition of small amount of noble metals (platinum or palladium) or reactive elements such as: hafnium, zirconium, yttrium and cerium has a beneficial effect on oxidation behavior. This beneficial effect includes an improvement of adhesion of alumina scales and reduction of oxide scale growth rate. Platinum and hafnium or zirconium modified aluminide coating were deposited on pure nickel using the electroplating and CVD methods. The coatings consisted of two layers: an outer, β-NiAl phase and the interdiffusion γ’-Ni3Al phase. Palladium dissolved in the whole coating, whereas hafnium and zirconium formed inclusions on the border of the layers. Samples were subjected to cyclic oxidation test at 1100 °C for 200h. Oxidation resistance of the palladium, Hf+Pd and Zr+Pd modified coatings deposited on pure nickel does not differ significantly, but is better than the oxidation resistance of the non-modified one.

Effect of Polishing Treatment on Rumpling of Oxide Scales on NiPtAl Coatings with Different Pt-Content

2013 ◽  
Vol 662 ◽  
pp. 383-386
Author(s):  
Peng Song ◽  
Jian Sheng Lu
Keyword(s):  
High Temperature ◽  
Nickel Aluminide ◽  
Aluminide Coating ◽  
Temperature Cycling ◽  
Oxide Surface ◽  
Temperature Oxidation ◽  
Aluminide Coatings ◽  
Temperature Exposure ◽  
Engine Components ◽  
Surface Morphologies

Pt-modified nickel aluminide coatings have been more widely used for protection of jet-engine components against high-temperature oxidation. The coating rumpling of two Pt-content NiPtAl coatings was studied in this paper during high temperature exposure. The results indicated that the NiPtAl coating grains size made a great contribution to the oxide surface morphologies, especially rumpling. Smaller grain size within high-Pt coating indicated a denser rumpling compared to low-Pt coating due to PtAl2 formation in the earlier coating. The failed local alumina at the ridges was also found on the low-Pt coating after cyclic oxidatioin. It was found that polished treatment resulted a comparatively flat and homogeneous oxide layer compared to as-received coatings. The temperature cycling could promote the aluminide coating rumpling, however, the polished treatment could not completely eliminate the roughening.

Aluminide Coating Formation on Hot Press Forming Steels

2010 ◽  
Vol 654-656 ◽  
pp. 326-329
Author(s):  
Dong Wei Fan ◽  
Han Soo Kim ◽  
Rho Bum Park ◽  
Bruno C. De Cooman
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
High Temperature Oxidation ◽  
Aluminide Coating ◽  
New Method ◽  
Hot Press ◽  
Temperature Oxidation ◽  
Press Forming ◽  
Coating Formation ◽  
Hot Press Forming

In the present work, the formation of an aluminide coating prior to Hot Press Forming (HPF) was investigated. It was found that the formation of Fe3Al phases could suppress coating degradation during the HPF process. This new method was studied as a way to simultaneously improve the coating ductility and achieve a good hot corrosion resistance. In this new method, the conventional type1 aluminized coating was transformed into an aluminide coating. This aluminide coating protects the steel from high temperature oxidation and enables its plastic deformation at high temperature. The effect of this new solution on the mechanical properties of HPF steel is reviewed in detail.

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