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.

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.

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.

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.

The Microstructure of Hafnium Modified Aluminide Coatings Deposited by CVD Method

2016 ◽  
Vol 844 ◽  
pp. 172-176
Author(s):  
Marek Góral ◽  
Maciej Pytel ◽  
Ryszard Filip ◽  
Andrzej Nowotnik
Keyword(s):  
Vapour Deposition ◽  
Aluminide Coating ◽  
Microstructural Analysis ◽  
Chemical Vapour ◽  
Deposition Process ◽  
Substrate Material ◽  
Process Time ◽  
Cvd Method ◽  
Aluminide Coatings ◽  
A Chain

The paper presents results of microstructural analysis of Hf-modified aluminide coatings. The coating was obtained using chemical vapour deposition (CVD) method at 1040°C using BPX-Pro 325 S equipment (Iond Bond). The deposition process time was 960 mintutes. The IN-718, IN-100 as well as CMSX-4 single-crystal nickel superalloys were the substrate material. The observation of coating was carried out using scanning electron microscopy. Chemical composition was analyzed using EDS method. The results showed that hafnium accumulates mainly on diffusion/additive layer interface and forms a „chain” of small precipitations. Hafnium was found in the additive NiAl layer of aluminide coating deposited on IN-100 superalloy. Its amount did not exceed 0.3 at %.

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 Effect of the Aluminide Coating on the Thermal Properties and Oxidation Resistance of Inconel 625 Ni-Base Superalloy

2015 ◽  
Vol 227 ◽  
pp. 313-316 ◽  
Author(s):  
Maryana Zagula-Yavorska ◽  
Jan Sieniawski ◽  
Ryszard Filip ◽  
Marcin Drajewicz
Keyword(s):  
Thermal Diffusivity ◽  
Outer Layer ◽  
Aluminide Coating ◽  
Diffusion Coating ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Optical Microscope ◽  
Coated Sample ◽  
Inconel 625 ◽  
Base Superalloy

An investigation was conducted to synthesize βNiAl coating on the nickel based superalloy Inconel 625 in the low activity chemical vapor deposition process (CVD). The deposition was carried out for 8 hours at 1050°C using the BPXpro3252 IonBond company equipment. Surface morphology and cross-section microstructure of the diffusion coating were studied and compared using an optical microscope, an X-ray diffractometer and a scanning electron microscope (SEM) equipped with an energy dispersive spectroscope. It was found that 29 μm thick aluminide coating consisted of two layers: an outer one and the inner interdiffusion one. The outer layer consisted of the βNiAl phase. The inner one consisted of the βNiAl phase with chromium, molybdenum and niobium carbides (M23C6 and MC type) inclusions. Outer layer hardness was about 564 HV0.002 while interdiffusion layer hardness was about 725 HV0.002. Thermal diffusivity of Inconel 625 superalloy with and without coating was measured using a NETZSCH model 427 laser flash diffusivity apparatus. The thermal diffusivity measurements were conducted in the argon atmosphere at the temperature interval 20 - 1200 oC. Thermal diffusivity of the uncoated Inconel 625 Ni-base superalloy at the room temperature is about 2 mm2/s, while for the coated superalloy thermal diffusivity is about 2.8 mm2/s. The increase of the temperature from 20 to 1200 oC leads to the increase of the thermal diffusivity of the coated sample from 2.8 to 5.6 mm2/s. Cyclic oxidation tests for both coated and uncoated superalloys were performed at 1100°C for 1000 h in the air atmosphere. The aluminized samples exhibited a small mass increase and the α-Al2O3 scale was formed during the oxidation test.

Microstructure and Oxidation Resistance of an Aluminide Coating on the Nickel Based Superalloy Mar M247 Deposited by the CVD Aluminizing Process

2013 ◽  
Vol 58 (3) ◽  
pp. 697-701 ◽  
Author(s):  
M. Zielińska ◽  
M. Zagula-Yavorska ◽  
J. Sieniawski ◽  
R. Filip
Keyword(s):  
Aluminide Coating ◽  
Diffusion Coating ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Small Mass ◽  
Optical Microscope ◽  
Oxidation Test ◽  
Nickel Based Superalloy ◽  
Air Atmosphere ◽  
Mass Increase

Abstract An investigation was conducted to synthesize βNiAl coating on the nickel based superalloy Mar M247 in a chemical vapor deposition process (CVD). The low activity process of aluminizing was carried out for 8 hours at the temperature 1050°C. Surface morphology and cross-section microstructure of the diffusion coating were studied and compared by using an optical microscope, a scanning electron microscope (SEM) equipped with energy dispersive spectroscopy and an X-ray diffractometer. It was found that aluminide coating with the thickness of 37 μm consisted of two layers: an outer one and the inner interdiffusion one. The outer layer consists of single phase βNiAl. The inner one, consisted of βNiAl phase and carbides: MC and M23C6 types which were originally present in the substrate. Cyclic oxidation test was performed at 1000°C for 1000h in the air atmosphere. The aluminized samples exhibited a small mass increase and the α- Al2O3 oxide formed during oxidation test had a good adherence to the coating. The decrease of aluminum content in the coating with the prolongation of the oxidation time and the phase transformation of βNiAl to γ’ Ni3Al and to γNi solid solution were observed. The samples without the coating showed a strong mass decrease in comparison to the coated samples.

Advanced Chemical Vapor Aluminizing Technology: Co-Deposition Process and Doped Aluminized Coatings

2012 ◽  
Author(s):  
Hristo Strakov ◽  
Vasileios Papageorgiou ◽  
Renato Bonetti ◽  
Val Lieberman ◽  
Audie Scott
Keyword(s):  
Chemical Vapor ◽  
Deposition Process ◽  
Metal Chloride ◽  
Coating Properties ◽  
Tight Control ◽  
Metal Chlorides ◽  
Metal Coatings ◽  
Aluminide Coatings ◽  
Base Materials ◽  
Coating Composition

Chemical Vapor Aluminizing (CVA) is used for more than 20 years to protect blades and vanes in the hot section of aero- and land based turbines against oxidation and hot corrosion [1]. Modern CVA is an advanced process capable of controlled alloying the coating with additional elements using metal chlorides and tight control of the coating composition. CVA processes offer a number of advantages over conventional pack and above-the-pack cementation. This paper deals with the industrial CVA technology to produce multi-component coatings using different metal chloride generating devices. Specific examples illustrate the influence of the coating parameters and base materials on the NiAl-based coatings microstructure and composition. Advanced co-deposition CVA processes with addition of different metal elements to the aluminide coatings are presented. Modified coating properties and structures of multiple metal coatings with elements like Al, Cr, Si, Co, Y and others will be discussed.

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