Oxidation Resistance Properties Research Articles

Characterization of Ti-48Al-2Cr fabricated by multi-wire arc additive manufacturing: Microstructure, mechanical, and oxidation resistance properties

Utilizing a multi-wire arc additive manufacturing process applied with high-frequency induction heating wire technology (MWAAM-HF) proposed in this study, Ti-48Al-2Cr alloy straight-walled component was fabricated. During the MWAAM-HF process, three types of wires melt simultaneously and transfer smoothly into the weld pool to form satisfactory component without discernible cracks. The upper and lower regions have higher hardness compared to the middle region in both Z and Y direction. Along the Y direction, the upper region exhibited the highest UTS and YS, while the minimum values were observed along the Z direction. Superior wear resistance was observed in the upper and lower regions. Distinct regions exhibited different levels of high-temperature oxidation resistance and the upper region has superior high-temperature oxidation resistance.

Lightweight, thermally insulating SiBCN/Al2O3 ceramic aerogel with enhanced high-temperature resistance and electromagnetic wave absorption performance

Owing to tunable dielectric properties, light weight and high porosity, polymer-derived SiBCN ceramic aerogels possess significant application prospects in electromagnetic wave (EMW) absorption and thermal insulation. However, due to inadequate oxidation resistance, the structural collapse and performance deterioration of SiBCN aerogels will easily occur in high-temperature aerobic environments, limiting their application. Herein, to address this issue, a novel and straightforward strategy based on typical polymer-derived-ceramic (PDC) aerogel method and impregnation with boehmite sol was proposed for synthesizing SiBCN/Al2O3 composite ceramic aerogels. The microstructure, phase composition, thermal insulation, oxidation resistance and EMW absorption properties of SiBCN/Al2O3 ceramic aerogels were investigated. The resulting SiBCN/Al2O3 composite aerogel demonstrates superior high-temperature structural stability, exhibiting an ultra-low linear shrinkage of only 6.5 % following heat treatment at 1200 °C for 2 h in air. Additionally, the composite aerogel shows a low thermal conductivity of 0.039 W/mK and a low density of 0.112 g/cm3. The SiBCN/Al2O3 composite aerogel, composed of dielectric SiBCN, conductive free carbon, and insulating alumina, demonstrates outstanding EMW absorption properties with a minimum reflection loss of −48.6 dB and an effective bandwidth of 5.8 GHz. The enhanced microwave absorption performance is mainly attributed to the improved impedance matching, multiple reflection, and enhanced interfacial polarization resulting from the introduction of Al2O3. Given prominent oxidation resistance, thermal insulation and EMW absorption properties, the SiBCN/Al2O3 composite aerogel paves the way for developing microwave absorption and thermal insulation integrated material in high-speed vehicles.

Carboxymethyl chitosan/peach gum polysaccharide packaging film incorporating Citrus sinensis essential oil effectively enhances the quality preservation of strawberries

Developing food packaging films loaded with plant extracts is a research hotspot. As natural preservatives, essential oils possess potent antibacterial and antioxidant properties. However, films loaded with essential oils face challenges in use for food preservation and flavor perception because of the strong aroma and volatility of components of the oils. In this study, natural, nontoxic Citrus sinensis essential oil (CSEO) was incorporated into blended films composed of carboxymethyl chitosan (CMCS) and peach gum polysaccharide (PGP), and the film properties were characterized. The CMCS/PGP films exhibited favorable performance (e.g., flexibility and antimicrobial activity). Addition of CSEO significantly improved the ultraviolet (UV)-barrier, oxidation resistance, hydrophobicity, and antimicrobial properties of the composite films. CPC1.0 film (containing 50:50 CMCS/PGP [w/w] and 1.0 % CSEO) showed enhanced elongation at break (99.59 ± 1.22 %), UV barrier performance (>85 % at 0.2–0.4 μm), and bactericidal activity (99.12 % for Staphylococcus aureus (S.aureus) and 93.62 % for Escherichia coli(E.coli)) compared with CMCS films. Packaging strawberries in CPC1.0 film maintained TSS (7.10 ± 0.26) and TA (0.77 ± 0.03) of the fruit, particularly flavor, resulting in a shelf-life of 6–8 days at room temperature. In soil, CPC1.0 film degraded by 78.53 % (by weight) in 10 days. This study shows that C. sinensis essential oil-loaded CMCS/PGP film has potential for application in fruit preservation and flavor retention.

Effect of bias voltage on high-temperature oxidation resistance and electrical properties of Mn–Co coating with metal interconnects for solid oxide fuel cell

Abstract This study investigated the effects of bias voltage on the microstructure, high-temperature oxidation resistance, electrical conductivity, element diffusion, and barrier of chromium poisoning cathode of Mn–Co coating on the surface of SOFCs metal interconnect SUS441 ferritic stainless steel. A series of Mn–Co coatings were prepared by magnetron sputtering technique at different bias voltages (−10, −50, −90 V) and oxidized at high temperatures for 175 h at 850 °C in an air environment. The results showed that the surface of each coating before oxidation exhibited a cauliflower-like morphology, with the crystallinity of the coating increasing with higher bias voltage. After high-temperature oxidation, especially the Mn–Co coatings prepared at −90 V bias, a dense and stable MnCo2O4 spinel structure was formed, which is crucial in inhibiting the growth of the Cr2O3 oxide layer. In addition, the coating also exhibits excellent electrical conductivity (Ea = 0.35 eV), good high-temperature oxidation resistance (1.182 mg cm−2), and a stronger ability to prevent the diffusion of Cr elements.

Cost-effective construction of graphene-based high-temperature electric heating coating with oxidation resistance and high mechanical properties

Cost-effective construction of graphene-based high-temperature electric heating coating with oxidation resistance and high mechanical properties

Influence of Al2O3 and h-BN on Wear and Corrosion Performance of IN625 Nickel-Based Coating

IN625 offers high-temperature oxidation resistance, wear resistance, and stable chemical properties. To improve the corrosion and wear resistance of the Q345B steel surface, two types of metal matrix composites (IN625 + 1% Al2O3 and IN625 + 1% h-BN) were applied to the substrate surface using the laser cladding process. This study analyzed the hardness, electrochemical corrosion, friction, and wear properties of both the laser-clad specimens and the substrates. The results show that (1) the hardness and wear resistance of the fusion-coated coating were significantly improved compared with the base material. Notably, the hardness increased by 19%, and the coefficient of friction decreased by 41% compared with the IN625 + 1% h-BN coating. Furthermore, the hardness and wear resistance of the IN625 + 1% h-BN coating were superior to those of the IN625 + 1% Al2O3 coating, attributed to the formation of eutectic compounds such as NiB and Ni2B in the dendritic region. (2) The corrosion resistance of the IN625 + 1% Al2O3 coating exceeds that of the IN625 + 1% h-BN coating and is also superior to that of the substrate. This improvement is primarily attributed to the addition of Al2O3, which enhances solid solution strengthening within the dendritic crystals of the fused-coating layer, reduces the percentage content of inclusions, and elevates the corrosion resistance of the coatings.

High-temperature oxidation resistance and wear properties of functionally graded CrHfNbTaTiN high-entropy nitride coating on Ti alloy

High-entropy nitrides have emerged as promising alternatives to traditional protective coatings due to their excellent comprehensive properties. However, there is still a long-standing technical challenge in the design and manufacture of hard and high-temperature stable high-entropy nitride coatings. This study utilized first-principles calculations to evaluate the thermodynamic stability between high-entropy nitrides and corresponding high-entropy metals, as well as titanium alloy substrates, confirming the rationality of the structural design of the functional gradient high-entropy ceramic coating. Subsequently, a double-glow plasma surface alloying technique were conducted to prepare a CrHfNbTaTiN functional gradient high-entropy ceramic coating on titanium alloy, followed by high-temperature cyclic oxidation experiments and high-temperature ball-on-disk wear tests. The research demonstrates that the gradient composition coating exhibits strong interfacial bonding, with an adhesion strength of around 40 N. It maintains excellent oxidation resistance in environments below 700 °C and displays good high-temperature wear resistance. This study contributes to providing insights and guidance for the further development of high-temperature, high-hardness, and wear-resistant materials.

The effect of configurational entropy and refractory elements on the oxidation behaviour of high entropy carbides containing up to eight refractory elements

High entropy carbides (HECs) have attracted increasing attention due to their promising oxidation resistance properties. The oxidation behaviour of (Zr,Nb,Ta,Hf,Cr)C (HEC5-Cr), (Ti,V,Cr,Zr,Nb,Hf,Ta,W)C (HEC8-Cr), and (Ti,V,Zr,Nb,Mo,Hf,Ta,W)C (HEC8-Mo) powders was compared and studied from room temperature to 1200 °C. It was found that the oxidation onset temperatures (OOT) for the HEC5-Cr, HEC8-Cr, and HEC8-Mo powders were 790 °C, 688 °C, and 617 °C respectively. The high entropy effect benefits the structural stability of carbides and thus improves their oxidation resistance. However, there is no direct correlation between the configurational entropy value and the OOT of the studied HECs. Compared to the configurational entropy value, the refractory elements in HECs and the thermal stability of the produced oxides have a more significant impact on the oxidation resistance of HECs. Most of the group IV, V, and VI metals except W, Mo, and V have main oxides suitable for high-temperature applications, making them attractive candidates for oxidation-resistant HECs.

High-speed laser cladding (Fe,Cu)-dopped Ni-Co protective coatings for SOFC MICs: From long-term oxidation behavior to mechanical stability

The long-term operation of intermediate temperature-solid oxide fuel cells (IT-SOFCs) could be significantly influenced by the stability of the interconnect itself, especially, its oxidation resistance under the cathode environment. To effectively prevent Cr-volatilization and improve the interconnector performance, application of highly dense and stable protective coatings over the interconnector is indispensable. In this work, Ni-Co-based alloy protective coatings doped with Fe and Cu were applied onto the 441 interconnector via a novel high-speed laser cladding technology. The microstructure evolution, phase composition, oxidation resistance, electrical conductivity and mechanical properties of the coated steels were investigated at different oxidation stages at 800 °C. It was found that the Ni33.8Co34Fe32.2-coated steel shows the best oxidation resistance and electrical properties. The oxidation rate (kp) and ASR of Ni33.8Co34Fe32.2-coated steel is respectively 4.44 × 10−13 g2 cm−4 s−1 and 25.55 mΩ cm2, significantly lower than the uncoated steel and Ni44.6Co44.7Cu10.7-coated steel at the end of 1000-h test cycle. The resultant conductivity of the Ni44.6Co44.7Cu10.7 and Ni33.8Co34Fe32.2-coated steels is approximately 7.8 and 4.1 S cm−1, respectively, which could meet the requirement for SOFC stacks. In addition, the nano-hardness of the Ni33.8Co34Fe32.2 and Ni44.6Co44.7Cu10.7-coated steels was found to be 8.3 GPa and 8.8 GPa, respectively, through nanoindentation testing. The improved surface hardness is attributed to grain refinement and increased oxide content on the coating surface. The results indicated that the Ni-Co-based alloy coatings effectively improved the long-term stability and mechanical property of the 441 interconnector under the SOFC cathode environment.

Enhanced mechanical property, high-temperature oxidation and ablation resistance of carbon fiber/phenolic composites reinforced by attapulgite

To meet the thermal protection and load-bearing requirements of ultra-high-speed vehicles, it is urgent to improve the ablation resistance, high-temperature oxidation resistance and mechanical properties of carbon fiber/ boron phenolic resin (CF/BPR) composites simultaneously. Herein, polyhedral oligomeric silsesquioxane-modified attapulgite (ASP) with abundant porous structure was successfully introduced into the CF/BPR (CF/ASPBPR). The co-effect of ceramization, high infrared emissivity, and low thermal conductivity endowed the CF/ASPBPR with desirable ablation resistance, where the linear ablation rate and mass ablation rate reduced to 0.038 mm/s and 0.035 g/s, respectively. Meanwhile, due to the high thermal stability and energy dissipation of ASP, the CF/ASPBPR also presented the interlaminar shear strength of 35.40 and 9.79 MPa before and after high-temperature treatment, which were 24 % and 63 % higher than that of CF/BPR, respectively. This study provides a promising pathway for preparing advanced thermal protection materials that can adapt to severe mechanical spalling and thermochemical erosion environments.

High Temperature Oxidation Behaviours of NiCoCrAlY alloys with High Al Content

Abstract MCrAlY coatings are of paramount importance in the protection of hot-end components from thermal oxidation and corrosion. The Al content is a crucial factor in enhancing the oxidation resistance properties of the coatings. This paper studies the oxidation behaviors of Ni-27.5Co-17Cr-xAl-0.5Y (x = 12 and 16 wt.%) alloys with high Al content. Following an oxidation process at 1100 °C over a period of 100 h, both alloys exhibit the oxide scales primarily consist of Al2O3 with minor amount of Co(Ni)Al2O4 spinels. The increased Al content results in a higher proportion of β phase, thereby promoting the development of an oxide scale in response to thermal exposure. This study provides insights into the fabrication of high Al content MCrAlY coatings with potential applications in next-generation thermal barrier coatings.

Novel synthesis of (Hf0.25Zr0.25Ti0.25Ta0.25)C-SiC biphasic ceramic micro-powders using single-source-precursor route

High-entropy carbides-SiC biphasic ceramics demonstrate outstanding mechanical and oxidation resistance properties. However, previous studies have predominantly focused on fabricating dense monolithic high-entropy carbides-SiC biphasic ceramics, with limited attention given to the production of high-purity, narrow particles size distribution high-entropy carbides-SiC biphasic ceramic powders. In this study, we successfully synthesized high-entropy carbides-SiC biphasic ceramic powders, specifically (Hf0.25Zr0.25Ta0.25Ti0.25)C-SiC, utilizing the polymer-derived-ceramic (PDC) route employing transition metal alcohol solution and methyltrimethoxysilane. The resultant powders exhibited an average particle size of ∼15 μm, with a narrow particle size distribution. Furthermore, variations in the heat treatment temperature demonstrated minimal impact on the particle size, while maintain compositional homogenous from nanoscale to microscale, and exhibiting low oxygen content less than 1.01 %. The introduction of the SiC phase also enhances the dynamic oxidation resistance of the high-entropy carbides. This pioneering work will not only provide a novel approach for obtaining other high-entropy carbides and SiC biphasic ceramic powder but also offers prospects for large-scale fabrication in industrial.

Understanding of the irradiation response of Cr-based ATF coatings using in-situ TEM

Although CrNb coated zirconium alloy materials are considered as ATF candidates with excellent oxidation resistance and mechanical properties, the irradiation response behavior under harsh and complex service conditions is still unrevealed. Here, we report the evolution of the microstructure of pure Cr and CrNb coatings with different Nb contents under simultaneous irradiation with Cr+-He+-H2+ triple ion beams at 633 K by using an advanced in-situ transmission electron microscope (TEM). The results show that CrNb coatings with high Nb content have better irradiation stability. Under high-temperature irradiation conditions, irradiation-induced oxidation and grain growth or crystallization are observed for both Cr-8 Nb with a nanocrystalline structure and Cr-18 Nb coatings with an almost amorphous structure, whereas Cr-37 Nb coatings maintains relatively intact in the amorphous phase after irradiation at a dose of 10 dpa. Based on the in-situ tracking of the microstructural evolution, it is revealed that the mechanism of irradiation-accelerated oxidation and crystallization of coatings originates from displacement cascades enhancing local atomic diffusion and rearrangement.

Structural, mechanical, and oxidation resistance properties of double glow plasma Ta[sbnd]W alloys

To enhance the performance of surface coatings on weaponry, TaW alloy layers with various W contents (7, 11.5, 13, 14, 14.5 and 16 at. %) were prepared on the surface of a PCrNi3MoVA gun steel substrate using double-glow plasma surface metallurgy technology. Mechanical properties, friction wear, and oxidation resistance were studied using scratch, hardness, and tribometer testers. The mechanical properties, interfacial properties, and effects on the oxidation performance of the gun steel substrate of the TaW alloy layer were calculated using first principles. The results indicated that the surface and cross-sectional microstructures of the TaW alloy layers were dense and free from obvious defects. With increasing W content, the thickness, hardness, and adhesive strength of the TaW alloy layer increased, and the coefficient of friction and wear rate decreased. The results of the calculations indicate that an increase in the W content enhances the elastic modulus of the TaW alloy and improves its brittleness, strength, and hardness. Doping with Ta and W atoms can increase the vacancy formation energy of Fe atoms in the Fe supercell, the adsorption energy of O atoms on the surface of Fe(110), and the diffusion barrier of O atoms in the Fe supercell and on the Fe(110) surface. Interdoping of Ta, W and Fe atoms at the Fe(110)/Ta-W(110) interface improved the bonding strength and stability of the interface, and the FeTa and FeW chemical bonds formed at the Fe(110)/Ta-W(110) interface ensured stable bonding at the interface. The incorporation of W into the TaW alloy layer enhanced both the mechanical and frictional properties of the alloy. It is well established that TaW alloys improve the antioxidant properties of gun steel substrates, thereby enhancing the performance of coatings on weaponry.

The mechanical properties and high-temperature oxidation behavior of (TiZr)65-x-yNb15Mo20SixAly refractory high entropy alloys

Herein, the mechanical properties and high-temperature oxidation of (TiZr)65-x-yNb15Mo20SixAly refractory high-entropy alloys were systematically investigated. Results indicate that alloying with Si improves the strength but reduces the plasticity of the alloy. Maintaining a proper ratio of Al/Si is crucial to achieve the optimal performance of the alloy. The (TiZr)50.5Nb15Mo20Si9.5Al5 has excellent high-temperature performance, with a yield strength of 815 MPa at 800°C and a compressive strain greater than 40 %. Moreover, the (TiZr)50.5Nb15Mo20Si9.5Al5 exhibits a superior oxidation resistance compared to (TiZr)55Nb15Mo20Si10 alloy at 1000℃. The introduction of Si enhances the oxidation resistance, decreases the diffusion of the Zr element at 1000 °C and facilitates internal oxidation and the creation of TiNb2O7. However, it is important to note that the doping of Al in the higher Si alloys has negative impacts on the oxidation resistance and mechanical properties.

Oxidation failure behavior and repair of the damaged SiC-ZrB2/SiC coating of C/C composites

The impacts of damage on the thermal barrier performance of SiC-ZrB2/SiC coating of C/C composites were investigated. The microstructure, chemical components, and thermal protection performance of the damaged coating before and after repair were analyzed, and the failure behavior of the damaged coated C/C composites was studied. After oxidation at 1500 °C for 360 min, the weight loss of the undamaged sample was −0.38 %, while that of the damaged sample reached 21.16 %. A repair method using polysiloxane and SiC-ZrB2 powder as repair agent was employed to recover the oxidation resistance property of the damaged coating. The repair agent generated SiOC ceramics after high-temperature treatment, covering the damaged area and bonding well with the original coating. The weight loss of the repaired sample was 2.4 %, which was significantly improved compared to the damaged coating. This work offers a research foundation for the optimization of the repair of damaged silicon-based ceramic coatings.

A review of high-entropy ceramics preparation methods, properties in different application fields and their regulation methods

High-entropy alloys (HEAs) provides a new way to develop new materials with adjustable performance due to their unique cocktail effect. Inspired by HEAs, a ceramic material with high-entropy effect has been developed, which was named high-entropy ceramics (HECs). With the introduction of the concept of entropy stability, research on HECs has developed rapidly. At present, research on the performance of HECs has extended to traditional performance such as thermomechanical performance, oxidation resistance, and magnetic properties, as well as emerging performance such as catalytic performance, optical properties, and radiation resistance. Based on the definition of HECs, this paper reviews the crystal structure and preparation methods of HECs and supplements the simulation calculation methods and descriptors which is suitable for HECs. In this paper, the performance of HECs at this stage is divided into traditional fields and emerging fields according to the application fields. A variety of performance regulation methods are reviewed, and the development and research directions of HECs are prospected.

High temperature oxidation resistance and thermodynamic properties of (TaNbZr)N and (TaNbZr)C quaternary ceramic coating

A TaNbZr-based quaternary ceramic coating with a metallurgical transition layer on a titanium alloy surface has been produced. The quaternary ceramic coatings exhibit a face-centered cubic structure and distinct structural orientation. The introduction of carbon and nitrogen significantly improved high-temperature oxidation resistance compared to metallic coatings in cyclic oxidation tests. Specifically, the (TaNbZr)N coating provided effective thermal protection during 800 °C cyclic oxidation for 100 hours (10 cycles). The phase stability and evolution of quaternary ceramic coatings were clarified using in-situ XRD. Further, first-principles calculations elucidated the enhanced thermal stability and high-temperature performance of (TaNbZr)N and (TaNbZr)C coatings.

A new nanocomposite membrane based on sulfonated polysulfone boron nitride for proton exchange membrane fuel cells: Its fabrication and characterization

Sulfonated polysulfone (SPSf) polymer is an alternative raw material in producing commercially used proton exchange membranes. On the other hand, hexagonal boron nitride (hBN) is one of the additives of interest for nanocomposite PEMs. In this study, nanocomposite membranes is fabricated and characterized with SPSf and hBN nanoparticles. The degree of sulfonation of the sulfonated polysulfone is determined by titration, and sulfonic acid bonds are investigated by Proton Nuclear Magnetic Resonance (1H NMR) analysis. SPSf is dissolved with dichloromethane, and hBN nanoparticles are added. After homogenizing the prepared solution with magnetic and ultrasonic stirrers, membranes are formed using Dr. Blade. 1H NMR, Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), X-Ray Diffractometer (XRD), and Thermogravimetric Analysis (TGA) analysis are examined the morphological, thermal, and organic compound structures of the membranes. Water uptake capacity, swelling ratio, proton conductivity, oxidative resistance, and mechanical properties of the membranes are determined. The highest water uptake capacity is obtained as 40.08 % in the membrane named SPSf-3 %hBN. Using hBN additive improved swelling ratio and thermal and mechanical strength properties. The proton conductivity values of polysulfone (PSf), SPSf, SPSf-1 %hBN, SPSf-2 %hBN, and SPSf-3 %hBN membranes are determined as 2.89, 6.84, 3.57, 10.8 and 5.12 mS cm−1, respectively. As a result of the analysis, it is observed that the nanocomposite membrane structure has both amorphous and crystalline homogeneous structure.

Synthesize and characterization of silver coated Ti powders from waste titanium chips by mechanical milling assisted electroless plating method

This study used an electroless silver (Ag) coating method on Ti powders obtained from waste turnings using mechanical milling, a recycling technique. Various parameters of Ag source and reducing agent ratios were utilized in the Ag coating processes. The results demonstrated that increasing the silver source and reducing agent ratios resulted in a more homogeneous and thicker Ag coating layer on Ti powders. The rise in the reduced silver ratio resulted in an increase in crystallite size compared to untreated particles, which was attributed to the reduction of residual dislocations in Ti through the presence of Ag. The amount of silver on silver-coated Ti powders ranged from 12.49 wt% to 24.4 wt%. Furthermore, an increase in the silver ratio significantly enhanced the oxidation resistance properties. The mass change with oxidation obtained from TGA analysis reduced from 26.31 wt% to 14.88 wt% with increasing silver coating layer on Ti powders.