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.

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.

scholarly journals The Influence of Pd and Zr Co-Doping on the Microstructure and Oxidation Resistance of Aluminide Coatings on the CMSX-4 Nickel Superalloy

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7579
Author(s):  
Jolanta Romanowska ◽  
Jerzy Morgiel ◽  
Maryana Zagula-Yavorska
Keyword(s):  
Oxidation Resistance ◽  
Chemical Vapor ◽  
Nickel Superalloy ◽  
Aircraft Industry ◽  
Co Doping ◽  
Cvd Method ◽  
Aluminide Coatings ◽  
Refractory Elements ◽  
Nial Phase ◽  
Better Than

Pd + Zr co-doped aluminide coatings were deposited on the CMSX-4 nickel superalloy, widely used in the aircraft industry, in order to investigate their microstructure and improvement of oxidation resistance. Palladium was deposited by the electrochemical method, whereas zirconium and aluminum by the chemical vapor deposition (CVD) method. Coatings consist of two zones: the additive and the interdiffusion one. The additive zone contains β–(Ni,Pd)Al phase with some zirconium-rich precipitates close to the coating’s surface, whereas the interdiffusion zone consists of the same β–(Ni,Pd)Al phase with inclusions of refractory elements that diffused from the substrate, so called topologically closed-packed phases. Palladium dissolves in the β–NiAl phase and β–(Ni,Pd)Al phase is being formed. Pd + Zr co-doping improved the oxidation resistance of analysed coatings better than Pd mono-doping. Mechanisms responsible for this phenomenon and the synergistic effect of palladium and zirconium are discussed.

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.

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.

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 Rhodium influence on the microstructure and oxidation behaviour of aluminide coatings deposited on pure nickel and nickel based superalloy

2019 ◽  
Vol 38 (2019) ◽  
pp. 621-627
Author(s):  
Maryana Zagula-Yavorska
Keyword(s):  
Oxidation Resistance ◽  
Layer Structure ◽  
Thick Layer ◽  
Xrd Analysis ◽  
Pure Nickel ◽  
Nickel Based Superalloy ◽  
Aluminide Coatings ◽  
Refractory Elements ◽  
Main Components ◽  
Main Component

AbstractThe rhodium 0,5 μm thick layer was deposited on pure nickel and CMSX 4 Ni-based superalloy using the electroplating method. The rhodium coated substrates were aluminized by the CVD method. Oxidation resistance of nonmodified and rhodium modified coatings deposited both on nickel and CMSX 4 superalloy was compared. The triple-layer structure of rhodium modified coatings deposited on pure nickel was found. The β-(Ni,Rh)Al, rhodium doped γ'-Ni3Al and rhodium doped γ-Ni(Al) phases were the main components of the coatings on pure nickel. Two layers – additive and interdiffusion ones were identified in coatings deposited on CMSX 4 superalloy. TEM, SEM and XRD analysis revealed that β-(Ni,Rh)Al phase was the main component of the additive layer. Moreover Topologically Closed-Pack σ phases containing refractory elements in the β-(Ni,Rh)Al matrix of the interdiffusion layer were found. The rhodium modified aluminide coatings have better oxidation resistance than the nonmodified ones both on the pure nickel and CMSX 4 superalloy.

Development and Oxidation of RexOy-Modified Aluminide Coating

2010 ◽  
Vol 142 ◽  
pp. 274-278 ◽  
Author(s):  
Jing Chong Zhang ◽  
Yue Bo Zhou
Keyword(s):  
Oxidation Resistance ◽  
Oxidation Behavior ◽  
Aluminide Coating ◽  
Composite Films ◽  
Pack Cementation ◽  
Reactive Element ◽  
Aluminide Coatings ◽  
Subsequent Step ◽  
Oxidation In Air

Reactive reactive element oxide RexOy (Re=Ce, Y)-modified aluminide coatings have been developed by the first step of co-electrodeposition of Ni with CeO2 or Y2O3 particls on pure Ni and the subsequent step of diffusional aluminizing on electrodeposited Ni-CeO2/or Y2O3 composite films using pack cementation method at 1100OC for 4 hr. By comparison, aluminizing was also performed with the same condition on an as-deposited Ni film without RexOy particles. The oxidation in air at 900OC indicated that the RexOy (Re=Ce, Y)-modified aluminide coatings were profoundly oxidation resistance as compared to the RexOy (Re=Ce, Y)-free coatings. The effect of CeO2 or Y2O3 on the oxidation behavior is discussed in detail.

The Influence of the Chemical Composition of Superalloys on the Oxidation Resistance of Aluminide Coating

2015 ◽  
Vol 227 ◽  
pp. 365-368
Author(s):  
Maryana Zagula-Yavorska ◽  
Jan Sieniawski ◽  
Ryszard Filip
Keyword(s):  
Chemical Composition ◽  
Oxidation Resistance ◽  
Aluminide Coating ◽  
Inconel 625 ◽  
Test Duration ◽  
Oxidation Test ◽  
Air Atmosphere ◽  
Aluminide Coatings ◽  
High Aluminum Content ◽  
High Aluminum

The aim of the present work was to determine the influence of chemical composition of the coating protected nickel based superalloys Inconel 713 LC, Inconel 625 and CMSX 4 on the oxidation resistance of aluminide coating. Protective aluminide coatings were deposited in the CVD process. The low activity aluminizing at the presence of AlCl3 and H2 was carried out. Cyclic oxidation test for both coated and uncoated superalloys was performed at 1100°C for 1000 h in the air atmosphere. Microstructure of aluminide coatings after oxidation test was investigated by a scanning electron microscopy (SEM) and an energy dispersive spectroscopy (EDS). The best oxidation resistance shows uncoated Inconel 713 LC superalloy. That is due to a relatively high aluminum content in this alloy. The aluminide coating deposited on the surface of Inconel 625 shows the largest oxidation resistance (insignificnt changes of mass for the whole test duration). Excellent oxidation resistance is a result of Al2O3 scale formation.

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