Cyclic Oxidation Resistance Research Articles

Enhanced cyclic oxidation resistance of Metcoloy II coated ASTM A53 Grade B steel by electric arc thermal spray

This study evaluates the enhanced cyclic oxidation resistance of Metcoloy II coatings applied to ASTM A53 Grade B steel substrates using electric arc thermal spray, across temperatures ranging from 500 °C to 700 °C. The research identifies distinct performance differences between coated and uncoated samples under cyclic oxidation conditions. Initially, both sample types exhibited mass increases due to oxide formation. However, uncoated samples developed non-protective iron oxides, while Metcoloy II coatings formed a protective layer of chromium and nickel oxides. During 500 oxidation cycles at 500 °C, uncoated samples showed a rapid mass increase, indicative of accelerated oxidation, whereas Metcoloy II coatings experienced a controlled mass gain, reflecting effective protection by chromium and aluminum oxides. At 700 °C, the mass variation trends were similar for both types initially; however, uncoated samples suffered significant mass loss due to iron oxide volatilization, emphasizing their susceptibility. Conversely, Metcoloy II coatings exhibited a reduced but steady mass increase, indicating their resilience under high-temperature conditions. Microstructural analysis confirmed the presence of a protective oxide layer in the coated samples, which is essential for reducing substrate oxidation. Although challenges such as coating detachment and thinning were observed, particularly at higher temperatures, Metcoloy II coatings maintained their protective role. This study highlights the coating's effectiveness in extending the lifespan of steel substrates subjected to cyclic oxidation, providing valuable insights for optimizing protective coatings in demanding industrial applications and advancing material science strategies for enhanced durability.

Microstructure, high-temperature cyclic oxidation, and hot corrosion behaviors of Inconel 718 alloy produced by laser-induction hybrid cladding

The microstructure evolution, cyclic oxidation, and hot corrosion behavior of the unheated-treated (As-built) and solution + double aging (SDA)-treated Inconel 718 alloys fabricated through laser-induction hybrid cladding (LIHC) were investigated. It was found that the as-built Inconel 718 alloy exhibits a columnar dendritic with intergranular Laves phase. After SDA-treated, γ", γ′, δ and carbide phases precipitated, the Laves phase became fine and dispersed. After cyclic oxidation, the Cr2O3 scales were formed on both as-built and SDA-treated LIHC-produced Inconel 718 alloy, which could provide good cyclic oxidation resistance for the Inconel 718 alloy. However, the as-built and SDA-treated LIHC-produced Inconel 718 alloy suffered severe hot corrosion in 95 wt% Na2SO4 + 5 wt% NaCl mixed salt solution and many corrosion products were generated, including Cr2O3, NiCr2O4, NaNbO3, Na2CrO4, NiFe2O4, Fe3O4, and NiO. Nevertheless, the SDA-treated sample showed better cyclic oxidation and hot corrosion resistance than the as-built sample, owing to the more compact Cr2O3 scale.

Long-term effects of soft-chromising Ni-electroplated AISI 441 commodity steel for SOC stack interconnects

Using commodity steel AISI 441 with Ni-based oxide coatings can facilitate large-scale interconnect manufacturing for solid oxide cell stacks, but adverse Ni-diffusion limits the high-temperature suitability. As a remedy, chromium is here added to the steel by a soft-chromising treatment. The (cyclic) oxidation resistance of virgin and soft-chromised AISI 441 is evaluated up to 8300 h at 780 °C, and further benchmarked against more commonly used Crofer 22 APU, with a Co(Mn)-spinel coating. Results revealed lowest isothermal oxidation kinetics for the soft-chromised, Ni-coated AISI 441, further preventing oxide spallation otherwise observed during thermal cycling of the virgin AISI 441 counterpart.

Cyclic oxidation resistance and self-healing properties of HfB2-doped glass composite coatings at 900 °C

HfB2-doped glass coating exhibits superior cyclic antioxidative performance compared to pure glass coating. The HfB2 particles inhibit the precipitation of crystals with low thermal expansion coefficient, mitigating the risk of fish-scaling failure. In addition, the HfB2-doped glass composite coating, with high contents of amorphous phases, maintains its viscous flow properties even after multiple high temperature cyclic oxidations, which enables it to self-heal. Moreover, the oxidation product (B2O3) of HfB2 enhances network connectivity of the glass system, providing more unsaturated sites for the chemical bonding of the self-healing process.

High-temperature cyclic oxidation of micro- and nano-ZrO2–25wt.%CeO2–2.5wt.%Y2O3 thermal barrier coatings at 1300 °C

In this study, the high-temperature cyclic oxidation resistance of micro- and nano-ZrO2–25wt.%CeO2–2.5wt.%Y2O3 (CYSZ) thermal barrier coatings (TBCs) was investigated. The TBCs were applied on IN738LC/CoNiCrAlY using the atmospheric plasma spray (APS) technique and subjected to high-temperature cyclic oxidation through 5-h cycles at 1300 °C. Various characterization techniques, including X-ray diffraction (XRD), Raman spectroscopy, nanoindentation, and field-emission scanning electron microscopy (FESEM), were used to assess the TBCs. Results indicated that annealing tetragonal zirconia at 1300 °C can generate antiphase boundary defects. The Young's modulus and hardness of nano- and micro-CYSZ TBCs decrease with the increase of antiphase boundary density. XRD and Raman results, the phase transformation behavior of tetragonal zirconia can be correlated to antiphase boundary density. Furthermore, the study showed that the nano-CSZ TBC has better oxidation resistance than the micro-CYSZ TBC at 1300 °C.

Effect of Solution Heat-Treatment on the Oxidation Resistance of Ni-Base Single-Crystal Superalloy

To clarify the effect of solution heat-treatment on the oxidation resistance of Ni-base single-crystal superalloy TMS-238, the evaluation of dendrite/inter-dendrite segregation of alloying elements in the as-cast and heat-treated samples, and its effect on cyclic oxidation resistance were investigated. Cyclic oxidation test results at 1100 °C for up to 150 cycles clearly showed that the as-cast samples with element segregations had lower oxidation resistance compared to heat-treated samples with homogeneous structure. Further, for the as-cast sample, rapid growth and spallation of oxide consisting of NiO, Cr2O3, and Al2O3 were observed around the dendrite core for 10 cycles of oxidation. Analysis of sub-surface on sample isothermally oxidized at 1100 °C for 10 minutes showed that rapid oxide growth is due to the formation of discontinuous Al2O3 layer at dendrite core with lower Al concentration. Furthermore, in this study, the threshold value of Al concentration and Gibbs energy for the formation of continuous Al2O3 layer were estimated and determined to be around 5.2 wt pct and − 556.6 ± 0.5 kJ/mol, respectively. This indicated that the solution heat-treatment for TMS-238 should be conducted above 1305 °C for exhibiting oxidation resistance at 1100 °C, to meet the threshold value within the whole region between dendrite and inter-dendrite.

Isothermal and cyclic oxidation behavior of in-situ grown MoSi2-SiC coating on Mo substrate at 1300 °C

We prepared the in-situ grown composite coating layer on Mo substrate to improve the resistance of MoSi2 coating against cyclic oxidation by introducing SiC reinforcement to reduce the thermal expansion mismatch with Mo substrate. Composite coating of MoSi2–19.3 vol% SiC was fabricated using a two-step approach of Mo2C coating on Mo substrate followed by siliconizing to achieve uniform dispersion of nanosized SiC particles in a matrix of equiaxed MoSi2 grains. The superior performance of this coating over monolithic MoSi2 coating was clearly demonstrated through evaluations of bot its isothermal and cyclic oxidation behavior at 1300 °C. In both coatings, diffusion-limited growth of oxide film was observed as indicated by parabolic weight gain up to 100 h at 1300 °C. Slightly faster oxidation rate in this isothermal test was observed in the composite coating and mainly attributed to the fast oxygen transport through open pores and blowholes created by CO gas evolution from the internal oxidation of SiC particles. Composite coating gave rise to drastic improvement of cyclic oxidation resistance at 1300 °C while monolithic MoSi2 coating broke into pieces in less than 35 cycles. Both equiaxed grains of MoSi2 and SiC dispersion was effective in suppressing the occurrence of through-thickness cracks in coating layer due to lower thermal stress generated during cooling to room temperature.

Cyclic Oxidation Resistance of MoSi2 Added FeCrAlTiY Coatings on ST41 Steel at 700oC Prepared by a Flame Spraying Technique

Advanced power generation will be operated at higher temperatures and pressure to achieve higher efficiency and reduce CO2 emission. This may significantly impact the use of carbon steel that previously has been used in boiler fabrication. In thi

On the rumpling mechanism in nanocrystalline coatings: Improved by reactive magnetron sputtering with oxygen

• The O dopped nanocrystalline coating is prepared by reactive magnetron sputtering. • The doping of O significantly improves the oxidation resistance of the coating. • The surface rumpling behaviors on coatings is retarded by oxygen. Surface rumpling is detrimental to high temperature protective coatings as it shortens their lifetime and leads to adhesion losses and unexpected corrosion degradation. The driving force and mass transport mechanism behind of rumpling remains to be clarified. In the present investigation, we subjected two types of nanocrystalline coating systems to avoid the influence of interdiffusion on rumpling study. One group was an ordinary nanocrystalline coating, and the other group was designed and prepared with trace oxygen by reactive magnetron sputtering. Systematic cyclic oxidation test at 1100 °C was also carried out. Results show the ordinary nanocrystalline coating oxidized rapidly, which leads to the fast consumption of Al and the acceleration of phase transition in the coating. Meanwhile, severe surface rumpling is observed due to the stress release of nanocrystals through plastic deformation. Besides, the reactive doping of oxygen can significantly reduce the consumption process of Al in nanocrystalline coating. The rumpling is controlled due to the improvement of coefficient of thermal expansion and Young's modulus of the coating. Thereafter, the cyclic oxidation resistance is improved.

Enhancing hot oxidation resistance of the HVOF-sprayed NiCoCrAlTaY coating by alumina nanoparticles via a modified suspension route

The effect of alumina (Al2O3) nanoparticles on the hot oxidation behavior of NiCoCrAlTaY coating is investigated. High velocity oxygen fuel (HVOF) technique was employed to deposit coatings on a single crystal CMSX-4 Ni-based superalloy. Different amounts of α-Al2O3 nanoparticles (3, 6 and 9 wt%) were added to NiCoCrAlTaY powder via a modified suspension route. By this modification, the Al2O3 nanoparticles were adhered on the surface of the atomized metallic NiCoCrAlTaY powders with a relatively uniform distribution. The composite powder was then sprayed on the superalloy substrate by an industrial HVOF route. The cyclic hot oxidation resistance of the coatings was evaluated at 1100 °C. Results showed that the coating with 6 wt% nano-Al2O3 experienced significantly better oxidation performance. The presence of nano-Al2O3 in the coating accelerated the formation of α-Al2O3 dense oxide layer and, thereby, delayed diffusion of other elements to the surface. Adding more Al₂O₃ nanoparticles up to 9 wt% led to an increase in porosity and surface roughness of the coating which decreased oxidation resistance.

Predicting oxidation‐limited lifetime of Ni‐Al‐Cr porous radiant burners made by combustion synthesis

Ni-Al intermetallic alloys have superior high-temperature properties such as excellent oxidation resistance and high yield strength, making them particularly attractive as materials for the fabrication of porous components of energy conversion and combustion devices. In this study, the cyclic oxidation resistance of highly permeable Ni-Al-Cr alloys has been investigated. The porous alloys with a structure of irregular porous scaffold comprised of welded mm-sized spheroidal strut elements forming a net of mm-sized interconnected pore channels (porosity of 0.55–0.60, specific surface area below 10−3 m2/g) were manufactured by the combustion synthesis method using μm-sized Ni, Al, and Cr powders of commercial purity as starting reagents. The surface area of alloys exposed to oxidation was calculated with an accuracy of 6% using quantitative 2D stereology. The cyclic oxidation tests were conducted in dry artificial air at 1150 ℃ for 100 h. The Ni‐Al‐Cr alloys, compared to Ni‐Al alloys, exhibited a twofold increased oxidation resistance because of decreased scale spallation. The porous alloys were also tested in a combustion environment. The lifetime prediction showed that Ni‐Al‐Cr radiant burners could be used for > 10,000 h at a temperature of 1000 ℃, which makes them relevant for application in domestic combustion appliances such as water heating boilers.

Microstructure Investigation and Cyclic Oxidation Resistance of Ce-Si-Modified Aluminide Coating Deposited by Pack Cementation on Inconel 738LC

The synergistic effect of Si and Ce addition on the oxidation resistance of a pack cementation aluminide coating applied on a Ni-based IN738LC superalloy substrate was investigated in this study. The structural and thermal influences of both Si and Ce, focusing on morphology, oxidation behavior, and scale spallation tendency, are accordingly discussed based on the experimental results using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray analyses (EDX). For this purpose, the oxidation resistance of the modified coatings was evaluated by measuring the weight gain of the coated samples after 16 h for each cycle at 1100 °C for a total of 50 cycles of the oxidation process. The investigations indicated that Si addition to the modified aluminide coating improves the oxidation resistance through the formation of β-NiAl and δ-Ni2Al3 phases, and also δ-Ni2Si phases. Furthermore, the addition of 1% Ce to the modified aluminide coating enhances the formation of the fine-grained microstructure of the β-NiAl and δ-Ni2Al3 and reduces the outward/inward diffusion of elements (so-called blocking effect), which significantly modifies the cyclic oxidation resistance. The oxidation enhancement also may be attributed to synergistic effects of Ce and Si addition during the deposition process that reduce the inward oxygen diffusion and reduce the growth rate of α-Al2O3 during oxidation tests.

Hot corrosion and cyclic oxidation performance of a PtAl2-dispersed (Ni,Pt)Al coating prepared by low-activity high-temperature aluminizing

The dual phase PtAl 2 -dispersed (Ni,Pt)Al coating (DP coating) and single phase (Ni,Pt)Al coating (SP coating) have been prepared simultaneously with an intermediate Pt content at the surface before low-activity high-temperature aluminizing process. Hot corrosion and cyclic oxidation performance of these two Pt-modified coatings are investigated in comparison with unmodified NiAl coating (UM coating). The results show that DP coating displays better hot corrosion resistance than SP and UM coating due to its higher Al content and faster Al diffusion rate in PtAl 2 phase. The cyclic oxidation resistance of DP coating is comparable to SP coating, while lighter rumpling is achieved at the surface of DP coating. This is because the volume change accompanied by phase transformation from ζ-PtAl 2 to β-(Ni,Pt)Al in DP coating is less than that from β-(Ni,Pt)Al to γ’-Ni 3 Al in SP coating. Moreover, ζ-PtAl 2 is superior to β-(Ni,Pt)Al in creep resistance, which also qualifies DP coating with less rumpling than SP coating with the same residual stress. • PtAl 2 -dispersed (Ni,Pt)Al coating was prepared with an intermediate Pt content at the surface before LAHT aluminizing. • PtAl 2 -dispersed (Ni,Pt)Al coating is superior to (Ni,Pt)Al coating in hot corrosion resistance at 900 °C. • PtAl 2 -dispersed (Ni,Pt)Al coating showed lighter rumpling than (Ni,Pt)Al coating during cyclic oxidation at 1100 °C. • PtAl 2 -dispersed (Ni,Pt)Al coating makes up the disadvantages of both the pure (Ni,Pt)Al and PtAl 2 coating.

Improvement of cyclic oxidation resistance of a β-(Ni,Pt)Al coating by the addition of Ni/Ni-Re layer at 1150 ℃

This paper studied the effect of adding Ni/NiRe layer on the high temperature oxidation behavior of β-(Ni,Pt)Al coating. Cyclic oxidation test of β-(Ni,Pt)Al coating, 0Re-(Ni,Pt)Al coating and 1Re-(Ni,Pt)Al coating were investigated at 1150 ℃ in this paper. Results indicated that adding Ni in the coating signally relieved the internal oxidation and improved the adhesion of scale for 0Re-(Ni,Pt)Al coating. Doping Re further enhanced cyclic oxidation property of 1Re-(Ni,Pt)Al coating. Besides, the oxidation process of three coatings, the effect of Ni/Ni-Re layer on the spallation of oxide scale and the formation mechanism of big holes were discussed.

High temperature oxidation performance of the electrodeposited SiO2 coating incorporated with Ni nanoparticle

Ni nanoparticle incorporated SiO2 coating was fabricated on Ti48Al2Nb2Cr alloy by electro-codeposition. Results showed that the Ni-SiO2 composite coating exhibits good isothermal and cyclic oxidation resistance at 900 ºC. The incorporation of Ni particles can adjust the coating thermal stress. After oxidation, no crack or pore can be found in the Ni-SiO2 composite coating. The consumption of the inward diffused oxygen could reduce the oxygen partial pressure at the coating/substrate interface, therefore promoting the selective oxidation of Ti48Al2Nb2Cr to form Al2O3. Owing to the good compatibility with SiO2, the oxidation product of NiO could strengthen the structure of the coating.

Improving the oxidation resistance of thermoelectric Mg2Si leg with silica coating

Due to the volatile and oxidation nature of Mg, Mg2Si based thermoelectric legs degrade faster when exposed to ppm level of oxygen during mid-temperature range operation. Here, we have established a modified sol–gel technique to get an oxidation-resistant SiO2 coating on the Mg2Si thermoelectric legs. The cyclic thermal ageing stability, oxidation resistance, and thermoelectric properties of the SiO2 coated Mg2Si have been investigated. The SiO2 coated Mg2Si is stable after ageing for 200 h at 823 K in air, and there is no degradation in the thermoelectric properties due to atmospheric exposure. It is thus a promising technique to increase the life span of Mg2Si based thermoelectric materials for waste heat recovery in automobiles and heavy industries.

Development of a Novel Bond Coat Material with Excellent Cyclic Oxidation Resistance

Development of a Novel Bond Coat Material with Excellent Cyclic Oxidation Resistance

The role of Dy doping on cyclic oxidation behavior of Al-Si coating on new cobalt-based γ/γ′ superalloy

The Al-Si-Dy coating is prepared on the γ′-strengthened cobalt-based superalloys by pack cementation method. Cyclic oxidation resistance of the coating at 1050 ℃ is investigated through experimental and computing methods. The cycle oxidation life of the coating is more than 1.5 times that of Al-Si coating. The oxide scale on Al-Si-Dy coating is denser and has stronger adhesion compared to Al-Si coating. Dy doping improves the cyclic oxidation resistance of Al-Si coated sample. The superior cyclic oxidation resistance of the coating is ascribed to enhanced adhesion energy of oxide scale, which is caused by stronger Dy–O bond.

Negative effect of Hf and Zr co-doping on alumina film growth of nickel-aluminium single-crystals during thermal cyclic oxidation

ABSTRACT The microstructure and cyclic oxidation behaviour of Hf and Zr co-doped B2 NiAl single-crystal alloys at 1473 K were investigated. Hf and Zr co-precipitated into one phase during alloy manufacturing. The RE-free single-crystal alloy obtained a double-layered alumina film comprised of outer equiaxed grains and inner columnar grains and exhibited lower oxidation rate than the corresponding poly-crystal alloy, while the co-doped single-crystal alloy displayed higher oxidation rate than the RE-free single-crystal alloy and no synergistic effect was discovered. The effect of Hf and Zr co-doping on the growth behaviour of the alumina film was discussed. It is proposed that the existence of grain boundaries is an important precondition for activating the reactive element effect. The absence of grain boundaries significantly weakened the positive effect of Hf and Zr co-doping and distinctly magnified its negative effect on the cyclic oxidation resistance of the alloy in the meantime. Highlights Cyclic oxidation behaviour of Hf and Zr co-doped NiAl single-crystals is compared. The undoped alloy obtains a double-layered alumina film during oxidation. The co-doped alloy shows higher alumina film growth rate than the undoped alloy. The absence of alloy grain boundaries suppresses the reactive element effect.

Preparation and cyclic oxidation resistance of Hf-doped NiAl coating

NiAl coating, 5Hf-NiAl coating and 15Hf-NiAl coating were prepared on Ni-based superalloy by electroplating, arc ion plating (AIP) and subsequent vacuum annealing. Cyclic oxidation behavior of the three coatings was investigated at 1100 ℃. 5Hf-NiAl coating and 15f-NiAl coating exhibited excellent adhesion between thermally growth oxide (TGO) and coating. The uniformly dispersed Hf-rich precipitates contributed to the cyclic oxidation resistance. The oxidation mechanism and effect of Hf on the morphologies, rumpling and adhesion of TGO were discussed as well.