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.

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.

Formation, Characterization, and Wear Behavior of Aluminide Coating on Mirrax® ESR Steel by Low-Temperature Aluminizing Process

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Tuba Yener ◽  
Azmi Erdogan ◽  
Mustafa Sabri Gök ◽  
Sakin Zeytin
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Low Temperature ◽  
Room Temperature ◽  
Wear Behavior ◽  
Aluminide Coating ◽  
Pure Aluminum ◽  
Dry Sliding Wear ◽  
Thickness Variation ◽  
Wear Tests

Abstract The aim of this study was to investigate the effect of low-temperature aluminizing process on the microstructure and dry sliding wear properties of Mirrax steel. Low-temperature aluminizing process was applied on Mirrax steel at 600, 650, and 700 °C for 2, 4, and 6 h. The packs for the process were prepared using pure aluminum powder as aluminum deposition source. Ammonium chloride NH4Cl and Seydisehir Al2O3 powder were used as the activator and the inert filler, respectively. Scanning electron microscope (SEM)/energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analysis were applied for characterization of the coating surfaces. The through-thickness variation in the layer microstructure was determined and it was found to vary between 1 µm and 45 µm which increased with higher process temperature and time. After the deposition process, the coating layer hardness increased to 1000 HVN, whereas the hardness of the matrix was 250 HVN. The wear tests were performed using a ball-on-disc tribometer under 5 N load at room temperature and 500 °C on aluminized and untreated Mirrax steel. In both room temperature and high-temperature wear tests, it was determined that the aluminizing process increased the wear resistance of Mirrax steel. Increasing aluminizing time and temperature also increased the wear resistance. The uncoated and thin-coated samples generally exhibited wear in the form of plastic deformation and adhesion related ruptures. A high degree of tribological layer was observed on the wear trace on samples with high coating thickness, especially in high-temperature tests. Therefore, the volume losses in these samples were induced by fatigue crack formation and delamination.

The Influence of Turbine Blade Geometry and Process Parameters on the Structure of Zr Modified Aluminide Coatings Deposited by CVD Method on the ZS6K Nickel Superalloy

2013 ◽  
Vol 197 ◽  
pp. 58-63
Author(s):  
Marek Góral ◽  
Maciej Pytel ◽  
Ryszard Filip ◽  
Jan Sieniawski
Keyword(s):  
Chemical Composition ◽  
Turbine Blade ◽  
Process Parameters ◽  
Aluminide Coating ◽  
Turbine Blades ◽  
Leading Edge ◽  
Nickel Superalloy ◽  
Influence Of Process Parameters ◽  
Aluminide Coatings ◽  
Blade Geometry

The Zr modified aluminide coatings is an alternative concept for replacing Pt-modified aluminide bondcoat for thermal barrier coatings. In the paper the influence of process parameters on the chemical composition and the thickness of aluminide coatings will be presented. The zirconia-doped aluminide coating was deposited on turbine blades made from ZS6K nickel superalloy during the low-activity CVD process. In recent work the influence of turbine blade geometry on thickness of coating was observed. The thickest coating was observed on the trailing and leading edge on the blade cross-section. In the conducted research, the light and scanning electron microscopy were used as well as the EDS chemical composition microanalysis.

The Influence of Deposition Process on Structure of Platinum-Modifed Aluminide Coatings O Ni-Base Superalloy

2011 ◽  
Vol 465 ◽  
pp. 247-250 ◽  
Author(s):  
Lucjan Swadźba ◽  
Ginter Nawrat ◽  
Boguslaw Mendala ◽  
Marek Goral
Keyword(s):  
Protective Coatings ◽  
Base Alloy ◽  
Turbine Blades ◽  
Chemical Vapour ◽  
Base Material ◽  
Deposition Process ◽  
Pack Cementation ◽  
Aluminide Coatings ◽  
Platinum Layer ◽  
Base Superalloy

The modern jet engines used in commercial and military aircrafts are characterized by operating temperature in turbine section above 1000oC. The Ni-base superalloy turbine blades and vanes working in high temperature in very aggressive environment require using of protective coatings. The aluminide coatings are widely used to protect this engine parts. The pack cementation, out of pack and chemical vapour deposition (CVD) technologies are usually used to produce this type of coating. The aluminide coatings can be modified by platinum or other elements. The Pt-modified aluminide coatings are characterized by better oxidation and corrosion resistance in comparison with conventional aluminide coatings and can be used as a bond coat for Thermal Barrier Coatings deposited by EB-PVD technology. In present study the influence of deposition technology and their’s parameters on structure and chemical composition of Pt-aluminide coatings are presented. The base material for coatings was a Inconel 738 Ni-base superalloy. The first step of coatings production were Pt electroplating with different thickness of platinum layer. The second step of coating production was aluminising process. The aluminide coatings were produced by pack cementation and out of pack technologies. Additional the influence of heat treatment of base alloy with coatings was investigated. The structure of all deposited coatings was observed by scanning electron microscopy and the chemical and phase composition of coatings were investigated by EDS and XRD methods. The observed coatings were characterized by two types of structure: first based on NiAlPt phase obtained on thin Pt layer and the second with additional presence of PtAl2 phase on the thick Pt layer.

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 Influence of Surface Preparation Method on Microstructure of HF-Modified Aluminide Coatings Deposited by CVD Method on Rene 80 and MAR M-247 Nickel Superalloys

2016 ◽  
Vol 844 ◽  
pp. 177-180
Author(s):  
Ryszard Filip ◽  
Maciej Pytel ◽  
Andrzej Nowotnik
Keyword(s):  
Vapour Deposition ◽  
Base Alloy ◽  
Aluminide Coating ◽  
Chemical Vapour ◽  
Surface Preparation ◽  
Substrate Thickness ◽  
Nickel Superalloys ◽  
Average Amount ◽  
Cvd Method ◽  
Aluminide Coatings

In the article the hafnium modified aluminide coatings deposited using chemical vapour deposition (CVD) method were analyzed. The influence of surface treatment (grinding, sandblasting with different pressures) on microstructure of coatings were described. The Re 80 and M-247 nickel superalloys were used as substrate. Thickness of the obtained aluminide coating was in the range 32-45 mm on Re 80 and 40-45 mm on M-247 respectively. The average amount of Al in the additive layer was 22-24 wt% on Re 80 and about 21 wt % on M-247 base alloy. The total amount of hafnium in coatings did not exceed 2.5 wt % - usuallly below 0.5 wt %. The conducted research has shown that there is no strong influence of surface preparation methodology on microstructure of aluminide coatings obtained by CVD method.

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 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 %.

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.

Evaluation of Simple Aluminide and Platinum Modified Aluminide Coatings on High Pressure Turbine Blades After Factory Engine Testing-Round II

1992 ◽  
Author(s):  
Jeffrey A. Connor
Keyword(s):  
High Pressure ◽  
Turbine Blades ◽  
Chemical Vapor ◽  
Pack Cementation ◽  
Nickel Base Superalloy ◽  
High Pressure Turbine ◽  
Engine Operation ◽  
Temperature Oxidation ◽  
Aluminide Coatings ◽  
Engine Testing

This paper presents results of factory engine testing of simple aluminide and platinum modified aluminide coatings. Simple aluminide coatings were produced using pack cementation processes. Platinum modified aluminide coatings were produced using three aluminiding processes; pack cementation, above-the-pack or out-of-contact processing, and chemical vapor deposition. These coatings were evaluated on both directionally solidified and single crystal nickel base superalloy turbine blades. These high pressure turbine blades were tested in a commercial high bypass turbofan engine operating predominantly in a high temperature oxidation environment. Included in this paper are discussions of coatings phase stability, coating growth due to diffusion during engine operation, comparison of coating performance and assessment of remaining coating life after engine testing.

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