Aluminizing of Nickel-Based Superalloys Grade IN 738 by Powder Liquid Coating

Visuttipitukul, Patama; Limvanutpong, Nuntiya; Wangyao, Panyawat

doi:10.2320/matertrans.m2009382

Cited by 23 publications

(9 citation statements)

References 8 publications

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“…The LPL layer where the amount of nickel is higher is composed of the Ni‐rich β phase with low precipitates because the solubility of alloying elements in Al‐rich β is much lower than that of Ni‐rich β, which has led to the high density of precipitates in HPL. [ 11,34 ] The EDS analyzes which are taken from different points of the coating also confirm the mentioned state. Coarse precipitations are observed in the lower areas of the coating adjacent to the substrate which is also shown in the substrate.…”

Section: Resultsmentioning

confidence: 56%

“…During the formation of the coating on the base alloy, an almost high density of secondary phases is formed due to the insolubility of these phases in the Ni 2 Al 3 and Al‐rich β‐NiAl phases. In a similar investigation, Goward et al and Rasmussen et al [ 33,37 ] reported that these Cr‐rich precipitates have mainly consisted of the α‐Cr phase, and according to another study, [ 34 ] it was stated that after dissolving of Cr into the Ni 2 Al 3 phase and reaching its solubility (about 4 wt.% of Cr), the AlCr 2 phase can accordingly precipitate. Finally, due to the high percentage of Cr in different parts of this study and its low solubility, which is about 17% in the NiAl phase, about 4 wt.% in the Ni 2 Al 3 phase, and about 9 wt.% in the Ni 3 Al phase, it can be said that most of the precipitates formed in the ground phase are chromides.…”

Section: Resultsmentioning

confidence: 94%

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A novel approach to the protection of internal passageways of gas turbine blades by aluminide coating: Evaluation of oxidation behavior

Jokar

Ghadami

Azimzadeh

et al. 2022

Materials & Corrosion

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Aluminum powder, cellulose acetate, and acetone were used to have the desired coating microstructure, suitable viscosity, and good wettability. The as‐cast IN‐738 was used as the substrate. Different holes with a diameter of 1 mm were drilled. The results of scanning electron microscopy and X‐ray diffraction analyses show that a uniform aluminide coating with a thickness of about 100–120 μm covers the entire inner surface of the hole and the desired β‐NiAl phase is formed. An artificial neural network was used in MATLAB software, and according to surface drawn obtained from mathematical modeling, it was concluded that with slurry viscosity in the range of 200–250 cp and the amount of applied slurry with a value of 20–30 mg cm−2 a suitable coating can be obtained. The oxidation test at 1000°C was performed by the thermogravimetric method for 150 h and the Kp constant for aluminide coatings and uncoated superalloy are successfully calculated to be 0.0034 and 0.0086 mg2 cm−4 h, respectively.

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Section: Resultsmentioning

confidence: 56%

Section: Resultsmentioning

confidence: 94%

A novel approach to the protection of internal passageways of gas turbine blades by aluminide coating: Evaluation of oxidation behavior

Jokar

Ghadami

Azimzadeh

et al. 2022

Materials & Corrosion

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“…The results show that sub-parabolize mechanisms (short circuits) can be found. An oxide layers cracking, which sud-denly increases the surface area in contact with oxygen and speeds up the oxidation kinetic, may explain the difference between the theoretical value n=0.5 as indicated in a previous study [20,21].…”

Section: Effect Of Al 2 O 3 and Al Additions On Oxidation Resistancementioning

confidence: 68%

“…In [21], the authors looked into hot corrosion in the components of the gas turbine and came to a conclusion that it is one of the major causes of failure in gas turbine engines. For avoiding catastrophic failure, the hot corrosion should be completely avoided or recognized early, and the ultimate failure regarding turbine blades might be caused by a combination of the hot corrosion and an additional failure mechanism (for example, fatigue).…”

Section: Literature Review and Problem Statementmentioning

confidence: 99%

Investigation of evaluated temperature oxidation for IN-738 LC superalloy turbine blade thermally coated by AL2O3 using slurry coating process

Mousa

Alshadeedi

Attia

et al. 2022

EEJET

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The study aims to investigate the effect of Al2O3 and Al additions to Nickel-base superalloys as a coating layer on oxidation resistance, and structural behavior of nickel superalloys such as IN 738 LC. Nickel-base superalloys are popular as base materials for hot components in industrial gas turbines such as blades due to their superior mechanical performance and high-temperature oxidation resistance, but the combustion gases' existence generates hot oxidation at high temperatures for long durations of time, resulting in corrosion of turbine blades which lead to massive economic losses. Turbine blades used in Iraqi electrical gas power stations require costly maintenance using traditional processes regularly. These blades are made of nickel superalloys such as IN 738 LC(Inconel 738). Few scientists investigated the impact of Al2O3 or Al additions to Nickel-base superalloys as coating layer by using the slurry coating method on oxidation resistance to enhance the Nickel-base superalloy's oxidation resistance. In this study, IN 738 LC is coated with two different coating percentages, the first being (10 Al+90 Al2O3) and the second being (40 Al+60 Al2O3). Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD) were performed on all samples before and after oxidation. According to the results, SEM images of the surface revealed that the layer of the surface has a relatively moderated porosity value and that some of the coating layers contain micro-cracks. The best surface roughness of specimens coated with 60 % alumina+40 % aluminum was 5.752 nm. Whereas, the surface roughness of specimens coated with 90 % alumina+10 % aluminum was 6.367 nm.Results reveal that alloys with both Al2O3 and Al additions have reported a positive synergistic effect of the Al2O3and Al additions on oxidation resistance. Moreover,the NiCrAl2O3 thermal coating has good oxidation resistance and the effective temperature of anti-oxidation is raised to 1100 °C in turn reducing the maintenance period of turbine blades

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“…A common material for gas turbine applications is the nickel-based superalloy Inconel 625 (IN625), which has good hightemperature strength, creep resistance, corrosion resistance, and great weldability. Diffusion coating was created to protect the substrates at high temperatures so that superalloys may maintain their exceptional qualities for a longer period while working, improving properties, and raising operating temperatures [1,2,3]. It is required to modify the surface to increase oxidation and corrosion resistance.…”

Section: Introductionmentioning

confidence: 99%

Oxidation Behavior of Inconel 625 Alloy through Aliminide Diffusion Method Using Y2O3 and ZrO2 Nanoparticles

Jawhar

Abbass

Aziz

et al. 2023

ETJ

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Nano Y 2 O 3 and ZrO 2 particles were used in diffusion coating by the single-step pack cementation process • Effects of Y 2 O 3 and ZrO 2 on mechanical properties and oxidation resistance of coated Inconel 625 superalloy were analyzed • Microstructure of coated IN625 superalloy consists of an outer layer, a transition layer, and an interdiffusion zone • Adding Y 2 O 3 and ZrO 2 to the Cr-Comodified aluminide coating might increase the oxidation resistance The pack cementation process was used to create a type of Y 2 O 3 +ZrO 2 doped Cr-Co-modified aluminide coating that takes advantage of the synergistic effects of nano Y 2 O 3 and ZrO 2 particles. A Ni-based superalloy (type IN625 type) was coated with pack powder containing: Al as a source of aluminum; Cr as a source of chromium, Co as a source of cobalt, NH 4 Cl as a source of activator; nano Y 2 O 3 -ZrO 2 as a source of reactive element oxide; and Al 2 O 3 as a source of filler metal. The process was carried out for 6 hours at 1100 o C temperature. The microstructure characterization of the coating was performed by SEM, EDS, and XRD. It was found that the cross-section of the coating obtained was uniform and free from cracking. The maximum hardness value was found at the outer layer (997H.V.) and decreased toward the core sample core (366H.V.). The coating's microstructure consists of an outer layer, a transition layer, and an IDZ. The average coating thickness is 132.37, 36.11, and 37.65µm for the outer layer, transition layer, and IDZ, respectively. The XRD analysis of the coating system after 6 hours at 1100 o C revealed phases formed by AlNi 3 , CoO, Al-Cr-Co, and Cr 4 NiZr. The n (growth rate time constant) and Kp (parabolic rate constant) values increase with increased oxidation temperature. It was found that adding Zr and Y to the Cr-Co-modified aluminide coating might increase the oxidation resistance.

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Aluminizing of Nickel-Based Superalloys Grade IN 738 by Powder Liquid Coating

Cited by 23 publications

References 8 publications

A novel approach to the protection of internal passageways of gas turbine blades by aluminide coating: Evaluation of oxidation behavior

A novel approach to the protection of internal passageways of gas turbine blades by aluminide coating: Evaluation of oxidation behavior

Investigation of evaluated temperature oxidation for IN-738 LC superalloy turbine blade thermally coated by AL2O3 using slurry coating process

Oxidation Behavior of Inconel 625 Alloy through Aliminide Diffusion Method Using Y2O3 and ZrO2 Nanoparticles

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