Cladding Materials Research Articles

Review of Electrical Parameters Influence on Characteristics of Plasma Electrolytic Oxide Coating on Zircaloy

<p>Zircaloy-4 (Zr-4) is used as a fuel cladding material in Pressurized Water Reactor (PWR). Zr-4 as a cladding material works in extreme conditions in pressurized water up to 150 atm at 325 ˚C. In addition, the refuelling process in the reactor requires surface protection of the clay material to minimize corrosion and wear. One of the raising methods to enhance the corrosion resistance of the Zr-4 is by plasma electrolytic oxidation (PEO). Characteristics of the ceramic oxide layer produced by PEO are influenced by current density, type and composition of the electrolyte, and voltage mode. One of the challenges in the PEO development on the Zr-4 substrate is a high porosity with a range of 5%-20% and the low number (below 6%) of t-ZrO<sub>2</sub> phases in the inner and outer layers. Optimizing the electrical parameters is necessary to overcome this problem. The results of the literature study show that the cathodic current at the AC voltage plays an important role in determining the resulting plasma characteristics. Low duty cycle (cathodic current> 50%) produce plasma with high density, resulting in a low porosity layer. Oppositely, high duty cycle (cathodic current <50%) produced high content of t-ZrO<sub>2</sub> increase the mechanical resistance. Two-step PEO is beneficial in combining the low and high duty cycle to obtain the benefit of each step. </p>

Advanced corrosion-resistant materials for enhanced nuclear fuel performance: A conceptual review of innovations in fuel cladding against molten salt degradation

The increasing demand for efficient and sustainable nuclear power has led to the development of advanced corrosion-resistant materials that can significantly enhance nuclear fuel performance. This conceptual review focuses on the innovations in fuel cladding materials designed to resist degradation in molten salt environments, which are crucial for advanced nuclear reactors like molten salt reactors (MSRs). Fuel cladding serves as a critical barrier between the nuclear fuel and the reactor environment, and its ability to withstand extreme temperatures and corrosive conditions is essential for safe and efficient reactor operation. Recent advancements in materials science have introduced novel alloys and coatings that demonstrate superior corrosion resistance in molten salts, which are used as both coolants and fuel solvents in MSRs. These innovations include high-temperature nickel-based alloys, refractory metals, and ceramic coatings, which are engineered to reduce the effects of molten salt corrosion, such as oxidation, pitting, and embrittlement. By enhancing the durability of fuel cladding, these materials contribute to improved fuel performance, longer reactor lifespans, and increased safety. This review explores key developments in corrosion-resistant materials, emphasizing the mechanisms by which these materials mitigate molten salt degradation. Additionally, it highlights the challenges associated with material selection, fabrication, and long-term performance in the highly corrosive environments of advanced nuclear reactors. Ongoing research into these materials offers promising avenues for the future of nuclear energy, particularly in addressing the limitations of current fuel cladding technologies. In conclusion, the use of advanced corrosion-resistant materials represents a significant step toward enhancing the performance and safety of nuclear fuel, ensuring the viability of MSRs and other advanced reactor designs. Continued innovation in this field is essential for the future of nuclear power.

Innovation and possibility of various coating materials with microwave hybrid heating

Cavitation wear is causing considerable financial losses for a range of industries, such as chemical, food processing and hydropower plants. Microwave cladding process involves the application of a coating of another material over the surface of a specific material, which offers properties beneficial for high electrical conductivity, low loss tangent and excellent thermal stability. This review article is intended to provide a basic understanding of the properties of various types of microwave cladding materials. This chapter also emphasises on the characterisation of the samples produced through the microwave cladding on various substrate materials. Furthermore, this chapter describes the potential applications of the microwave cladding process in numerous engineering and industrial sectors. Additionally, this chapter also reports the potential future technological advancements in the field of microwave cladding process.

Interaction of Polymethyl Methacrylate with Boehmite-Filmed Aluminum Cladding Under Gamma Irradiation

This paper presents an overview of ongoing work to qualify the Advanced Test Reactor (ATR) driver fuel elements that have been affected by irradiation-degraded polymethyl methacrylate (PMMA) flux wands. Irradiation testing was performed on PMMA material in contact with aluminum clad material. The cladding was prefilmed with a boehmite oxide layer, an important feature of the ATR driver fuel. The effects on the boehmite layer due to gamma irradiation of the PMMA-aluminum clad system were investigated. PMMA embrittlement, followed by softening and degradation, occurred at high radiation levels. Adhesion between the cladding and irradiated PMMA was observed. Flow testing at prototypic ATR flow rates demonstrated the effective removal of the adhered material. Measurements of the boehmite layer thickness were performed, and Raman spectroscopy was utilized to detect the presence of boehmite in the irradiated PMMA material.

The Effect of Using Volcanic Tuff Aggregate with Different Grain Sizes in Facade Cladding Material on Physical and Mechanical Properties

The Effect of Using Volcanic Tuff Aggregate with Different Grain Sizes in Facade Cladding Material on Physical and Mechanical Properties

Impact of in-core fuel management on the radial peaking factor in the APR-1400 with accident-tolerance fuel cladding

This study provides an in-depth examination of the initial, transition, and equilibrium cycles of the APR-1400 reactor core, focusing on reference fuel cladding and ATF cladding systems. This research highlights the importance of in-core fuel management strategies, particularly checkerboard configuration, in maintaining safe and efficient reactor operations. The radial peaking factor (RPF) is an essential parameter in evaluating the core configuration, and a study demonstrated that the RPF can be effectively controlled below the threshold of 1.85 through careful fuel reshuffling and introducing new fuel assemblies. Key findings indicate that the RPF values vary across different cycles but remain within safe limits. Specifically, the RPFs for the initial, first transition, second transition, and equilibrium cycles are 1.36, 1.21, and 1.23; 1.43, 1.38, and 1.30; 1.64, 1.44, and 1.31; and 1.29, 1.33, and 1.66, respectively, measured at the beginning, middle, and end of each cycle. These results underscore the effectiveness of the proposed fuel management strategies in maintaining a stable and safe power distribution within the reactor core. This study also underscores the potential benefits of ATF cladding materials, such as chromium-coated zirconium, which offer enhanced resistance to high-temperature oxidation, thereby improving reactor safety under normal and accident conditions. The implementation of ATFs could lead to significant improvements in safety margins, operational efficiency, and overall reactor performance. This research contributes valuable insights into optimizing in-core fuel management practices for the APR-1400 reactor. This study lays a foundation for future studies and practical applications that could further enhance the safety and efficiency of nuclear power plants. By demonstrating the advantages of ATFs and effective fuel management, this study supports the continued development and deployment of advanced nuclear technologies, promoting greater public confidence in nuclear energy as a reliable and safe power source.

Hoop tensile properties and crack propagation investigation of 2D braided SiCf/SiC composite tubes: Experiments and simulations

SiCf/SiC composites are promising candidates for advanced pressurized water reactors (PWRs) fuel cladding materials due to their enhanced accident tolerance. Their mechanical properties are strongly influenced by the braided structure of continuous SiC fibers. This study fabricated SiCf/SiC composite tubes with braid angles ranging from 30° to 50°, evaluating their hoop tensile properties through expansion-due-to-compression (EDC) experiments and analyzing the damage process using finite element method simulation. Results indicate that variations in braid angles significantly affect structural density, thereby impacting mechanical strength under hoop tensile stress. Increased braid angles result in smaller pore units and higher pore density, leading to local stress concentrations and varied deflections at overlapping regions. The dynamic propagation behavior of cracks was investigated through acoustic and structural nondestructive testing methods. Finite element analysis of different braid configurations highlights the pivotal role of pore units in the initiation and propagation of hoop tensile cracks. This study enhances the understanding of toughening structures in 2D braided composites and provides a theoretical basis for future accident-tolerant fuel cladding design.

Unidirectional and highly dispersive grating emitters for silicon photonic beam steerers.

Grating emitters are the key component used in silicon photonic beam steerers to create light emission and allow dispersion-based steering. Conventional grating emitters are inefficient due to bidirectional emission, and their angular dispersion is only on the order of 0.1°/nm. In this paper, we develop unidirectional grating emitters by choosing a top cladding material with a refraction index higher than that of the bottom cladding. The refractive index difference allows the phase-matching condition to be satisfied only for the upward diffraction. We demonstrate experimentally grating emitters with a directionality of 83% and an angular dispersion of 0.79°/nm. These grating emitters have a simple device structure compatible with the standard silicon photonic platform.

Indentation parameters and corrosion resistance of explosive welded S30400/Q345R clad plates with heat treatment cycles

This study aims to clarify the indentation parameters and corrosion resistance of explosive welded S30400/Q345R clad plates with heat treatment cycles. A series of tests on the mechanical properties of the clad plate in the unseparated state of clad material (CM) and base material (BM) and its free surface corrosion resistance, as well as their evolution with stress relief heat treatment are studied and discussed. The results show that the severely carburised layer (SCL) that occurs on the stainless steel side of the heat treatment was the peak hardness of the entire clad plate, which was significantly reduced after four heat treatments. The worst mechanical performance was observed in three heat treatments. The reduction in free surface corrosion resistance of CM is linearly correlated with the number of heat treatments, but this does not hold true for BM. This study provides valuable references for the assessment of performance loss under heat treatment of clad plates.

Integrating machine learning and parametric design for energy-efficient building cladding systems in arid climates: Sport hall in Kerman

Climate change, driven by fossil fuel dependence, presents a significant challenge for the construction industry, particularly in energy-intensive regions like arid climates. This research investigates the potential of integrating machine learning and parametric optimization to enhance the energy efficiency of spatial structure domes in such environments. Focusing on a sports pavilion in Kerman, Iran, the study examines the crucial role of cladding systems in building energy performance. Employing a rigorous four-phase methodology, the research optimizes dome cladding materials for hot, dry climates using a dual objective function: energy cost and material cost. The process involves a comprehensive literature review, data-driven material selection, advanced energy simulations, and optimization analysis. Parametric modeling tools (Rhino, Grasshopper, Honeybee) facilitate the comparative analysis of various cladding systems. Multivariate Polynomial Regression (MPR) enables predictive modeling of energy consumption and material costs, streamlining the design process for architects. The optimized solution is a hybrid cladding model composed of 10 % polycarbonate and 90 % aluminum. Analysis reveals that the hybrid system offers superior energy optimization compared to pure aluminum (4.58 %) and polycarbonate (5.70 %). While polycarbonate has a lower initial material cost, the hybrid system achieves a balance between material expenditure and long-term energy efficiency. This highlights the importance of considering life-cycle costs when evaluating building envelope materials. This research advances a framework that leverages machine learning and parametric design for building envelope optimization. This framework empowers architects and engineers to create energy-efficient structures within arid environments, promoting a more sustainable built environment.

Magnetic Field Assisted Enhanced Sensitivity of Nonferromagnetic Materials Boosting the Carrier Transfer: Mechanistic Studies.

The performance of semiconductor sensors is determined by reaction kinetics, conductivity, and electron mobility, which are undoubtedly closely related to the electron motion behavior. Therefore, the effective regulation of electronic states is crucial for improving gas sensing properties. Previous methods of enhancing the gas-sensing performance have induced complex material modifications, and the extent of performance improvement is usually very limited. Further optimization of the gas sensing performance requires continuous efforts to advance new technologies. Toward this issue, a novel magnetic field-induced strategy is adopted to boost the carrier transfer efficiency of nonferromagnetic semiconductors. The gas sensing investigation results manifest that the applied magnetic field can effectively enhance the sensitivity and reduce the baseline resistance. The In2O3 NC-2 (In2O3 nanocubes) with an applied magnetic field have a greatly enhanced response of 161.4 toward 100 ppm formaldehyde, which is 2.5 times higher than that without magnetic field. The enhanced gas sensing properties can be mainly attributed to magnetization of reactive materials, which makes the orientation of electronic magnetic moments consistent, thus greatly contributing to reactivity. This work introduces a practical approach to effectively improve gas sensing performance without further morphology optimization, noble metal catalysis, structural modification, and material cladding. The results of this study provide new insights for designing novel gas sensors to improve the gas sensing performance.

Investigation on the influence of electrospark deposited 718 alloy coating on the penetration performance of 93 W rod

A ballistic experiment on a semi-infinite RHA target impacted by two thicknesses clade 93 W rods (200 μm 718 alloy and 400 μm 718 alloy) with an impact velocity of 1500 ± 50 m/s is conducted to investigate the influence of 93 W surface deposited coating on penetration performance. Moreover, the findings are compared with those of an unclad 93 W rod. This study aims to provide a comprehensive microstructural overview of the penetration process, including the solid-state penetrator flow and the exchange interaction mode of rod and target (R.T.) materials, using optical metallography and electron microscopy. Results indicate that the coating area is composed of approximately equiaxed or short columnar cellular crystals. Furthermore, a metallurgical fusion layer is formed between the substrate and the coating, ensuring excellent bonding strength of the coating. No significant difference in the rheological mode is found between the interfaces of the 200 μm 718 alloy and 93 W R.T. materials, while the 400 μm 718 alloy forms a barrier mix zone at the interface between the R.T. This phenomenon alters the exchange mode of the target material and affects the interface flow mechanism. The barrier mix zone also acts as a solid-state lubricant at the interface, reducing the resistance to the rod's penetration. The average penetration depth of the 400 μm clad rod is 6.89 % higher than that of the 93 W rod. This finding reveals the clad material enhances the rod's performance and provides self-lubricating characteristics.

Effects of Hf and/or Ti addition on the morphology, crystal, and metal/oxide interface structures of nanoparticles in FeCrAl-ODS steels

FeCrAl oxide dispersion strengthened (ODS) steel is one of the most promising candidate cladding materials due to its exceptional properties. For 3.8Al–0.46Hf (Fe–15Cr–2W–3.8Al–0.46Hf–0.32Y2O3) and 3Al–0.1Ti–0.6Hf (Fe–15Cr–2W–3Al–0.1Ti–0.6Hf–0.35Y2O3) ODS steels, the morphologies of matrix grains & nanoparticles, and the crystal structures of oxides & metal/oxide interface structures were studied by scanning transmission electron microscopy (STEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). For 3.8Al–0.46Hf and 3Al–0.1Ti–0.6Hf ODS steels, the mean grain size is 1.26 μm and 0.90 μm, respectively, and the dispersion morphology of nanoparticles in the latter is better than that of the former. Crystal & interface structures of 313 and 222 oxides in 3.8Al–0.46Hf and 3Al–0.13Ti–0.6Hf ODS steels were characterized, respectively. The proportions of Y–Hf–O and Y–Al–O particles in the former are 63.3 % and 29.1 %, respectively. However, the Y–Hf–O, Y–Al–O, and Y–Ti–O particles in the latter account for 74.8 %, 16.7 %, and 8.5 %, respectively. The much better dispersion morphology of oxides in 3Al–0.1Ti–0.6Hf ODS steel, relative to 3.8Al–0.46Hf ODS steel, is due to the much higher proportion of Y–Hf–O, the considerably lower proportion of Y–Al–O and the fairly high number fraction of Y–Ti–O. The study delved into the formation mechanisms of various oxides and the strengthening mechanisms in both ODS alloys.

State-of-the-Art Review: Effects of Using Cool Building Cladding Materials on Roofs

Cool roofs are roofing systems designed to reflect significant solar radiation, reducing heat absorption and subsequent cooling energy demands in buildings. This paper provides a comprehensive review of cool roof technologies, covering performance standards, material options, energy-saving potential, and hygrothermal considerations. The review examines provisions in current codes and standards, which specify minimum requirements for solar reflectance, thermal emittance, and solar reflectance index (SRI) values. These criteria often vary based on factors like roof slope, climate zone, and building type. Different cool roof materials are explored, including reflective paints and coatings that can be applied to existing roofs as cost-effective solutions. Several studies have demonstrated the energy performance benefits of cool roofs, showing significant reductions in cooling loads, indoor air temperatures, peak cooling demand, and overall cooling energy consumption compared to traditional roofs. However, hygrothermal performance must be evaluated, especially in cold climates, to optimize insulation levels and avoid moisture accumulation risks, as reduced heat absorption can alter moisture migration patterns within the building envelope. While cool roofs provide substantial energy savings in hot climates, further research is needed to validate modeling approaches against real-world studies, investigate the impact of seasonality and green spaces on cool roof efficacy and urban heat island mitigation, and explore energy-saving potential, moisture control, and condensation risks in cold and humid environments.

Effects of Tungsten Addition on the Microstructure and Properties of FeCoCrNiAl High-Entropy Alloy Coatings Fabricated via Laser Cladding.

This study examines the effects of different addition levels of tungsten (W) content on the microstructure, corrosion resistance, wear resistance, microhardness, and phase composition of coatings made from FeCoCrNiAl high-entropy alloy (HEA) using the laser cladding technique. Using a preset powder method, FeCoCrNiAlWx (where x represents the molar fraction of W, x = 0.0, 0.2, 0.4, 0.6, 0.8) HEA coatings were cladded onto the surface of 45 steel. The different cladding materials were tested for dry friction by using a reciprocating friction and wear testing machine. Subsequently, the detailed analysis of the microstructure, phase composition, corrosion resistance, wear traces, and hardness characteristics were carried out using a scanning electron microscope (SEM), X-ray diffractometer (XRD), electrochemical workstation, and microhardness tester. The results reveal that as the W content increases, the macro-morphology of the FeCoCrNiAlWx HEA cladding coating deteriorates; the microstructure of the FeCoCrNiAlWx HEA cladding coating, composed of μ phase and face-centered cubic solid solution, undergoes an evolution process from dendritic crystals to cellular crystals. Notably, with the increase in W content, the average microhardness of the cladding coating shows a significant upward trend, with FeCoCrNiAlW0.8 reaching an average hardness of 756.83 HV0.2, which is 2.97 times higher than the 45 steel substrate. At the same time, the friction coefficient of the cladding coating gradually decreases, indicating enhanced wear resistance. Specifically, the friction coefficients of FeCoCrNiAlW0.6 and FeCoCrNiAlW0.8 are similar, approximately 0.527. The friction and wear mechanisms are mainly adhesive and abrasive wear. In a 3.5 wt.% NaCl solution, the increase in W content results in a positive shift in the corrosion potential of the cladding coating. The FeCoCrNiAlW0.8 exhibits a corrosion potential approximately 403 mV higher than that of FeCoCrNiAl. The corrosion current density significantly decreases from 5.43 × 10-6 A/cm2 to 5.26 × 10-9 A/cm2, which suggests a significant enhancement in the corrosion resistance of the cladding coating.

Sustainability beyond the surface: Evaluating the long-term environmental and energy performance of selected cladding materials for housing retrofits

External walls, constituting the largest exposed surface area of the building envelope, face heightened susceptibility to environmental influences. In this study location, aesthetic con- siderations often overshadow environmental impact and comfort requirements in selecting exterior cladding materials. This paper investigates the energy performance, global warming potential, and thermal comfort aspects of carefully selected cladding materials, informed by an exhaustive literature review, for application in retrofit projects in Abuja, Nigeria. Energy con- sumption, carbon emissions, and temperature distributions were simulated using materials in a hypothetical single-floor residential building finished with cement-sand plaster. The findings show that gravel stone exhibits the most negligible environmental impact. In contrast, alumi- num and lightweight metal cladding panels contribute significantly to the embodied carbon of the building despite ranking as the most expensive materials. Insulating the test building with polyurethane boards yields substantial energy savings of up to 9% in cooling electricity, averting the need for added cladding. This study emphasizes the significance of adopting a multi-criterion approach in selecting façade cladding materials, prioritizing environmental and thermal considerations over aesthetic and cost benefits. The implications extend beyond mere emissions reduction, shedding light on the vital interplay between material choices on comfort and energy efficiency in building design.

Tribological behavior and characteristics of TIG surface cladded AlCoCrFeNi high-entropy alloy on 304L stainless steel

The present study examines the tribological properties of AlCoCrFeNi high-entropy alloy (HEA) surface cladded on 304L stainless steel via a Tungsten Inert Gas (TIG) heat source. Commercially pure powders of aluminum, cobalt, chromium, and nickel were ball-milled, mixed in specific ratios, and applied onto the substrate with polyvinyl alcohol as a binder. Cladding was performed with optimized parameters to create layers of HEA. Microstructural and EDS analysis revealed equiaxial dendrites rich in aluminum and nickel in dendritic (DI) areas, and rich in iron, chromium, and cobalt in interdendritic (ID) areas. Mixing entropy was calculated by consideration of EDS analysis of the cladding and based on the initial definition of a high-entropy alloy, the high-entropy nature of the cladding was confirmed. XRD analysis showed the presence of FCC, A2/B2, and hard σ phases. Surface alloyed material exhibited higher hardness compared to the base material, with an average of 540 HV versus 200 HV. A pin-on-disc wear test machine was used to assess tribological properties under different loads of 10, 20, and 40 N. The wear rates of the high-entropy cladded material were 36 and 50 % less than those of the 304L stainless steel under applied loads of 10 and 40 N, respectively, while their wear rates were almost similar at 20 N. Friction coefficients of HEA pins were notably lower than 304L at 10 and 20 N, with smoother profiles. Wear mechanisms of the HEA material varied with load: oxidative wear at 10 and 20 N due to the formation of an oxide layer, and abrasion and spallation at 40 N, resulting in a threefold increase in wear rate at this load. Overall, the study highlights the effectiveness of HEA cladding in improving tribological properties, especially under high applied load.

Microstructure and properties of Zircaloy-4 alloy under low-temperature diffusion bonding with a Ni-plated surface

Zircaloy-4, which is used as a structural material for nuclear cladding, requires precise bonding at low temperature in nuclear power applications. We achieved this using diffusion bonding with Ni plating on the surface of Zircaloy-4. We evaluated the performance of joints at temperatures between 650 and 780 °C. At 650 °C, the joint was successfully bonded. The joint exhibited a maximum shear strength of 207 MPa at 780 °C, which was twice as high as that produced by direct diffusion bonding at 700 °C under the same parameters. The interface was analyzed by using a combination of SEM and TEM to identify the presence of multilayered intermetallic compound layers in the joints. We investigated the mechanism of interface generation and determined the sequence of phase formation by Gibbs free energy calculations to be NiZr, Ni10Zr7, NiZr2, Ni7Zr2, and Ni3Zr. Through X-ray diffraction and cross-section elemental analysis of the fractures, we observed that, at lower temperatures, the joint fracture tended to occur in the Ni layer, whereas at higher temperatures, it occurred between Ni7Zr2 and Ni3Zr. The utilization of diffusion welding with Ni plating applied to the surface of Zircaloy-4 reduces the joining temperature and enhances the properties of the joint.

High-performance Li[sbnd]S battery separators based on F-element doped loofah sponge biomass carbon materials

Lithium-sulfur batteries are a new high-performance battery technology that consists of lithium metal as the negative electrode and sulfide material as the positive electrode. Compared with conventional lithium-ion batteries, LiS batteries offer higher energy density as well as cost advantages. However, the shuttle effect of polysulfides in LiS batteries can lead to serious degradation of cycling performance, etc., which hinders the commercialization of LiS batteries. For this reason, in this study, the green biomass material loofah sponge was used as a precursor, and the porous carbon material was produced by calcination after introducing the F element and used as a separator modifier to curb the shuttle effect, which is environmentally friendly, economical, and green. Comparative studies were conducted on ordinary PP separators, separators made of carbon materials before and after F-doping. The experimental results show that the F-doped porous carbon material cladding membrane improves the charge/discharge capacity, multiplication performance, and cycle stability of LiS batteries, which reflects the great potential in practical applications.

Improved understanding of the growth of blocky alpha in welded Zircaloy-4

Zirconium alloys are widely used in nuclear reactors as fuel cladding materials. Fuel cladding is used to contain the nuclear fuel and cladding tubes are typically sealed using welds. Welding of zirconium alloys can result in changes in the local microstructure, with the potential to grow so called ‘blocky α’ grains in the welded region during subsequent thermal processing and these blocky α grains have the potential to be detrimental to the integrity of the component. In this work, complimentary heating experiments with ex situ and in situ electron backscatter diffraction (EBSD) analysis are used to aid understanding of the blocky α grain growth within the weld region. These experiments reveal that blocky α grain growth is related to the prior-β (high temperature) microstructure, as grains grow adjacent to a prior-β grain boundary and the orientation of the growing α grain can be explained using neighbourhood orientations from this prior-β grain. This growth mechanism is explained via a simple mechanism which is related to the α grain orientations, grain boundary structures and local stored energy. Ultimately, our findings indicate that the likely grain growth (size and morphology) across the weld region can now be predicted from the initial as-welded microstructure.