Cladding Materials Research Articles

Optimization of Exterior Wall Cladding Materials for Residential Buildings Using the Non-Dominated Sorting Genetic Algorithm II (NSGAII) Based on the Integration of Building Information Modeling (BIM) and Life Cycle Assessment (LCA) for Energy Consumption: A Case Study

In today’s construction industry, a topic of paramount importance is reducing energy consumption within buildings. This study endeavors to combine Life Cycle Assessment (LCA) and Building Information Modeling (BIM) through a multi-objective optimization algorithm to enhance the environmental efficiency of buildings. The core objective is the optimization of materials used in the building’s outer shell to effectively curtail operational energy consumption. To achieve this, we employed BIM modeling, parametric simulations with the Energy Plus engine, and Athena to assess the embodied energy in materials. The multi-objective optimization algorithm NSGAII was harnessed to determine the most suitable materials. The results derived from the LCA and BIM analyses illustrate that the selection of optimal materials for residential building facades in Iran can lead to a remarkable 40% reduction in annual average energy consumption. Furthermore, this approach contributes significantly to mitigating global warming potential (GWP). Experts and architects can apply this method to evaluate and select the best materials for various building components, especially in high-rise buildings.

Multiphysics analysis of thermal mechanical behavior and tritium migration in FeCrAl and Cr-coated Zircaloy cladding under PWR normal operating and transient conditions

Both Cr-coated Zircaloy and the FeCrAl alloy have garnered attention as potential substitutes for PWR cladding materials, due to their impressive qualities, such as robust high-temperature oxidation and corrosion resistance. However, FeCrAl alloy is found to accelerate the tritium permeation throughout the cladding, this heightened tritium permeation prompts easier release from the cladding into the coolant. Consequently, the assessment of material tritium permeation becomes a crucial aspect in fuel performance analysis. In this work, the multiphysics models of Cr-coated Zircaloy and FeCrAl cladding are reviewed firstly. Then the multiphysics models are implemented in CAMPUS code and the validation of tritium migration model is presented. Subsequently, the fuel performance under normal and accident (LOCA and RIA) conditions and the tritium migration in three types of claddings are simulated and discussed. The simulation results show that the utilization of FeCrAl cladding, instead of Zircaloy, results in an overall reduction in fuel temperature under both normal and LOCA conditions. Furthermore, both the Cr-coated Zircaloy and FeCrAl cladding are found to effectively delay the cladding failure time under LOCA condition. However, the total strain of FeCrAl cladding is found to be significantly higher than that of the Cr-coated Zircaloy cladding under RIA condition. And the Cr-coated Zircaloy is found to have better tritium resistance effect than FeCrAl cladding, which greatly reduces the coolant contamination treatment. Therefore, based on the combined consideration of fuel performance and tritium resistance, Cr-coated Zircaloy emerges as the preferred candidate cladding over the FeCrAl cladding.

Transient fuel behavior analysis of UN fuel with a two-layered SiC cladding based on multiphysics method

Recently, UN fuel has emerged as a promising alternative to UO2 fuel due to its exceptional thermophysical attributes, including heightened thermal conductivity, elevated melting point, and increased fissile density. Meanwhile, SiC is recognized as a member of the next generation of accident-tolerant cladding materials owing to its impressive strength at high temperatures, resistance to creep, minimal thermal expansion, and improved irradiation characteristics. In this study, utilizing our developed fuel performance analysis code CAMPUS, we integrate a multiphysics model featuring UO2 fuel paired with a two-layered SiC cladding into the CAMPUS framework. Subsequently, we conduct simulations and analyses of the fuel performance for combinations such as UO2-two-layered SiC, UN-two-layered SiC, UN-Zircaloy, and UO2-Zircaloy. These evaluations encompass both standard operation scenarios and potential accident conditions within a pressurized water reactor (PWR). Notably, the incorporation of UN fuel demonstrates a significant reduction in maximum fuel temperature during normal operation, as well as under Loss-of-Coolant Accident (LOCA) and Reactivity Initiated Accident (RIA) conditions. However, upon introducing the two-layered SiC cladding, it becomes apparent that its temperature performance is somewhat inferior to that of Zircaloy under normal operation and RIA scenarios. Conversely, when subjected to a LOCA scenario, the thermal and mechanical characteristics of the two-layered SiC cladding outperform those of the Zircaloy cladding.

RESEARCH ON THE PHYSICAL PROPERTIES OF THE BUILDING STONES IN EAST BLACK SEE REGION

This study investigated the physical properties of Ünye stone (Ordu), Harşit granites (Giresun), and Trabzon gray stone (Trabzon) used as building materials in the Eastern Black Sea Region. Chemical components, thermal conductivity, compressive stress, water absorption, and abrasion percentages were determined. Ünye stone has small thermal conductivity coefficient values (0.67 W/mK), indicating that it can be used for thermal insulation and decorative purposes as briquettes, bricks, or wall cladding materials. Harşit granites have compressive stress and abrasion rate values of 113 MPa and 1.05%, respectively. Trabzon gray stone has compressive stress and abrasion rate values of 125 MPa and 1.13%, respectively. These results indicate that Harşit granite and Trabzon gray stone can be used as wall cladding materials and wear-resistant floor coverings. These three stones can be widely used because they are cheap and abundant.

Measurement system for in-situ estimation of instantaneous corrosion rate in supercritical water

Current research of cladding and in-core materials for the supercritical water reactor concept is focused on Fe-Cr-Ni alloys (e.g. 800 H, 310 S). Along the standard measurements of general corrosion rate of materials by exposure testing in autoclaves, where poor reproducibility is an issue, especially when comparing results from different experimental facilities, a good alternative may be the use of in-situ electrochemical measurements. The use of electrochemical methods is, however, more challenging due to complicated instrumentation as well as due to the supercritical water conditions. This paper is focused on the design of an experimental facility for in-situ electrochemical testing at supercritical water conditions, i.e. main circulating loop with autoclave, including the design of the electrode system, electrode leads and their surface insulation coating. Stability of electrochemical measurements has been tested using 2- and 3-electrode set-ups. Finally, surface insulation coating of the electrode leads with the best chemical and mechanical stability during experiment has been chosen for the presented application.

Upward flame spread behaviour of cladding materials on a medium-scale ventilated façade experimental setup with a single combustible wall

A parametric experimental study was performed to characterise the fire spread dynamics in a simplified ventilated façade using a medium-scale testing rig comprised of a non-combustible and a combustible cladding wall (1800 × 600 mm). Three different cavity widths and four different cladding materials were tested. Measurements of the flame height, the incident heat flux on the non-combustible cavity wall and oxygen consumption calorimetry were performed. A strong relationship between flame height and heat release rate was found for the growth phase of the fire. It has been shown that the time for encapsulation failure and subsequent cladding material core ignition decreased as the cavity width was reduced since the heat transfer to the walls was enhanced. The increase in the heat transfer to the opposite wall with all the materials could lead to external heat fluxes above the critical heat flux for ignition of a number of combustible cladding materials. This highlights the importance of considering the interaction of the products used in the façade and its geometry for the design of façade assemblies when accounting for the fire performance of the system. The results also show the need to understand the impact of the interaction between the design variables and the system performance, since the material performance observed at bench-scale may fail to capture the performance in heat transfer and flame spread scenarios observed at a system scale.

Deuterium transport behavior of 15-15Ti stainless steel for nuclear structural material in Gen-IV reactors

As a new type of nuclear reactor, the Gen-IV reactor attracts increasing interest from the industry. Tritium is produced in lead-cooled fast reactors (LFR), sodium-cooled fast reactor (SFR), and other Gen-IV reactors. It is necessary to study the tritium permeation behavior of 15-15Ti stainless steel as a candidate cladding and structural material in Gen-IV reactors. In this study, gas-driven permeation experiments were conducted to measure the high-temperature deuterium transport behavior parameters of 15-15Ti stainless steel. The results showed that the deuterium permeation behavior of 15-15Ti and 316L stainless steels is similar. Additionally, this study discussed the effects of microstructures and surface oxidation on the permeability of stainless steels. This study will aid in evaluating tritium permeation in lead-based fast reactors and other Gen-IV reactors and whether tritium permeation barrier or tritium-removal devices are necessary.

Concept of accident tolerant fuel in nuclear reactors

The excellent behavior of zirconium alloy under normal operating state as well as significant advantage of neutron economy have resulted in the use of zirconium alloy as the cladding material. However, extensive metal-water reaction in the event of severe accidents and subsequent hydrogen generation can be considered to be a big disadvantage for zirconium alloy. The Fukushima Daiichi Nuclear Plant accident has brought challenges to the nuclear industry and renewed attention about the idea of accident tolerant fuels (ATFs). Concept of ATFs is to mitigate the devastating interaction of steam at high temperature with fuel clad in off-normal condition of the reactor. These materials have higher resistance to core degradation, lower oxidation kinetics and can withstand against high temperature for a longer duration of time. Being in the direct contact with the coolant the accident tolerant fuel cladding plays an important role at high temperature in off-normal conditions. Many studies have been initiated worldwide to find an advanced oxidation-resistant alternative cladding material to enhance fuel performance and safety, specifically under accident conditions. One of the candidate materials for fuel cladding in LWRs is oxidation-resistant iron alloys. The stainless steel technology and the material science have been studied extensively and several new generations of increasingly higher performance steels are now commercially available that may offer significant performance improvements over the relatively simple austenitic steels that were utilized as cladding in some early commercial fission reactors. One study has been performed to find the reactivity impact of SiC and stainless steel as clad material on various parameters. This paper presents the results of a study that has been made to understand the reactor physics implications of using SiC and stainless steel as the cladding material.

Establishing pyrolysis kinetics for fire modelling and thermal analysis of polymeric cladding materials used in high-rise buildings

This research paper presents a comprehensive analysis of kinetics data concerning with the core materials of Aluminium Composite Panels (ACPs), with a specific focus on composite materials comprising mineral fillers and organic polymers. The study addresses the current scarcity of kinetics data for cladding panel core materials, particularly those with complex compositions involving mineral fillers and organic polymers, which poses a significant challenge for accurate fire modelling. The study aims to extract essential parameters, including activation energy, pre-exponential factors, and reaction orders, essential for precise fire modelling. This study involves Thermogravimetric Analysis (TGA) on three distinct cladding core materials, namely, ACP-1, ACP-2, and ACP-3, featuring varying proportions of organic polymer content (100%, 30%, and 7%) and exposure to different heating rates (5, 10, 15, and 20 K/min). By employing both model-free and model-based techniques in conjunction with TGA analysis, the study successfully derives kinetics data aligned with specific pyrolysis reaction stages. To validate the extracted kinetics data, the study conducted experimental tests utilising a Cone calorimeter. The results from these experiments showcased a strong correlation between fire performance parameters such as Total Heat Release (THR), Effective Heat of Combustion (EHC), and Mass Loss Rate (MLR) and the proportion of polymer in the cladding composites. Furthermore, the study examined the implications of the derived kinetics data within the Fire Dynamics Simulator (FDS). The insights gained from this research substantially contribute to our comprehension of core material kinetics in ACPs, while also offering valuable input for fire dynamics simulations, thereby enhancing fire safety modelling and practices knowledge in the field of construction materials and design.

Construction of a Strain-Hardening Diagram to Analyze the State of Stress in the Fuel-Element Cladding Material

Construction of a Strain-Hardening Diagram to Analyze the State of Stress in the Fuel-Element Cladding Material

Hydrothermal corrosion of PVD and cold spray Cr-coatings on Zircaloy-4 in hydrogenated and oxygenated LWR coolant environments

Accident tolerant fuel (ATF) are currently being developed as part of an international effort to modify or replace zirconium-based cladding materials in light water reactors. The main objective of ATF cladding materials is to improve fuel reliability and safety during accident scenarios. Thus, these materials should perform comparable to or better than the current zirconium alloy. One of the ATF concepts explores modifying standard Zircaloy cladding by coating their outer surface. In this study, surface-modified Zr-4 is produced by depositing a protective coating of chromium through two different coating techniques, Physical Vapor Deposition (PVD) and Cold Spray (CS). The coated specimens were tested at ∼300 °C in out-of-pile autoclaves simulating Boiling Water Reactor (BWR) conditions. Results show that after one month of immersion, Cr-coated Zr-4 evidenced a small mass gain in hydrogenated environments. However, both types of coated specimens showed significant coating degradation and mass loss in oxygenated environments.

Research Progress of ODS FeCrAl Alloys-A Review of Composition Design.

After the Fukushima nuclear accident, the development of new accident-tolerant fuel cladding materials has become a research hotspot around the world. Due to its outstanding corrosion resistance, radiation resistance, and creep properties at elevated temperatures, the oxide dispersion strengthened (ODS) FeCrAl alloy, as one of the most promising candidate materials for accident-tolerant fuel cladding, has been extensively studied during the past decade. Recent research on chemical composition design as well as its effects on the microstructure and mechanical properties has been reviewed in this paper. In particular, the reasonable/optimized content of Cr is explained from the aspects of oxidation resistance, radiation resistance, and thermal stability. The essential role of the Al element in oxidation resistance, high-temperature stability, and workability was reviewed in detail. The roles of oxide-forming elements, i.e., Y (Y2O3), Ti, and Zr, and the solid solution strengthening element, i.e., W, were discussed. Additionally, their reasonable contents were summarized. Typical types of oxide, i.e., Y-Ti-O, Y-Al-O, and Y-Zr-O, and their formation mechanisms were also discussed in this paper. All aspects mentioned above provide an important reference for understanding the effects of composition design parameters on the properties of nuclear-level ODS FeCrAl alloy.

Influential Mechanism of Cr3C2 Content and Process Parameters on Crack Generation of Fe3Al/Cr3C2 Composites

In this paper, a brake cylinder coating comprising composite material of Fe3Al and Cr3C2 mixed powder was prepared by laser cladding onto carbon structural steel. The microstructure of the cladding materials was investigated through X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). The influence mechanism of the Cr3C2 content and process parameters on crack generation of Fe3Al/Cr3C2 composites were studied. The crack is mainly caused by the mismatch between the plastic phase of Fe2AlCr, the brittle phase of Fe3Al, and Cr7C3 in the cladding layer. With the increase in Cr3C2 content, Fe2AlCr and Cr7C3 in the cladding layer increased, while Fe3Al decreased. When the content of Cr7C3 is low, the cladding layer mainly reflects the plastic increase brought by Fe2AlCr; when the content of Cr7C3 is too much, the property of the cladding layer is reflected as the brittleness of Cr7C3. The number of cracks reached the lowest value at 15 wt.%. The process parameters mainly affect the dilution rate of the cladding layer and thus affect the content of Fe2AlCr.

Displacement cascade under high-energy irradiation and tensile property in Fe-Cr-Al alloys: A molecular dynamics simulation

Fe-Cr-Al alloy is considered as one of the most prospective accident-tolerant fuel cladding materials due to its excellently comprehensive properties. Irradiation performance evaluation of Fe-Cr-Al alloy is the key for successful development of fuel-clad system with enhanced accident tolerance. However, the microstructural response is largely dependent on irradiated conditions. In the present work, molecular dynamic method is employed to simulate the cascade collision processes under high-energy irradiation and tensile deformation behaviors of Fe-Cr-Al alloys. The threshold displacement energies (TDEs) in Fe-Cr-Al alloys are calculated at different temperatures and along various directions, and the TDEs along different directions exhibit significant anisotropy. The effect of alloy compositions on the displacement cascade of Fe-Cr-Al alloys is systematically studied, as well as the direction of the primary knock-on atom (PKA), temperature, and PKA energy. At 300 K and 700 K, no significant dependence between the number of surviving Frenkel pairs and PKA energies is observed in Fe-Cr-Al alloys under high-energy irradiation. High temperature and high-energy PKA could potentially lead to form large-sized interstitial clusters and a few small-sized vacancy clusters in Fe-Cr-Al alloys. Dislocations or dislocation loops can easily form at high temperatures and in high-energy irradiation. The effect of alloy compositions, temperatures and PKA energies on the tensile properties of Fe-Cr-Al alloys before and after irradiation, is systematically evaluated. By analyzing the corresponding yield strength, ultimate tensile strength and elastic modulus, Fe-Cr-Al alloys exhibit the characteristic of irradiation-induced hardening and embrittlement with the increase of PKA energy. As the temperature increases, the rigidity of alloys decreases while the irradiation embrittlement significantly increases.

Establishment and experimental verification of a three-dimensional finite element model for residual stress in surface processing of Inconel 718 alloy by laser cladding

The local load and residual stress changes of conventional forged Inconel 718 alloy can be simulated in a two-dimensional (2D) cutting simulation model, but the type and distribution of global residual stress field of the alloy cannot be predicted during laser cladding layer cutting. To address the shortcomings of conventional 2D cutting simulation models for forging Inconel 718 alloy, this paper proposed a 3D closed-loop finite element model, and taking the dry-side milling process of Inconel 718 alloy laser cladding layer as an example, the generation mechanism and distribution of residual stress are predicted during the machining process. Further testing of surface, near-surface, and subsurface residual stresses was conducted to analyze the specific distribution of residual stresses in the workpiece. The results indicated that the uneven distribution of cutting stress and temperature on the workpiece had a significant non-stationary thermal-mechanical effect on the surface of the machined workpiece; the distribution of surface residual stress was uneven, with the significant tensile residual stress at the workpiece boundary. As the depth increases, the influence of mechanical effects dominated, and the compressive residual stress was generated on the subsurface of the workpiece. Residual stress testing was conducted on the surface/near-surface, and the experimental results were consistent with the simulation results of the closed-loop simulation model. In the subsurface, residual stress showed a similar trend of change. This study compensated for the shortcomings of conventional finite element simulation and provided the reference value for the application of three-dimensional finite element simulation in laser cladding materials.

Microstructure dependent burst behavior of oxide dispersion–strengthened FeCrAl cladding

Oxide dispersion–strengthened (ODS) FeCrAl alloys are an advanced cladding material that combines the high-temperature steam oxidation resistance of conventional wrought FeCrAl with the irradiation resistance and high-temperature strength of nanostructured ferritic alloys. In the present study, the effect of microstructure on the performance of the ODS FeCrAl alloy system in light-water reactor–accident scenarios is evaluated using a combination of experimentation and modeling. ODS FeCrAl alloy with nominal composition Fe-12Cr-6Al-0.3Zr-0.3Y2O3 was produced into a thin-walled tube via high-precision tube rolling. A portion of the as-received (AR) tube was subjected to a full recrystallization heat treatment. Both variants were subjected to burst testing at Oak Ridge National Laboratory’s Severe Accident Test Station. The recrystallized tube exhibited burst temperature margins 200 °C higher than that of C26M, whereas the AR tube only achieved burst properties comparable to the wrought FeCrAl alloy. The burst experiments were simulated in the BISON finite element code through the development of new viscoplastic material databases for each heat treatment condition, informed by high temperature tensile tests of tube specimens and existing literature data on creep mechanisms. Finally, an ODS FeCrAl burst criterion was obtained using simulated burst experiments across the entire range of test conditions.

COMPOSITE GLASS-CRYSTAL FACING MATERIALS BASED ON WASTE FROM THE PHOSPHORUS INDUSTRY AND CULLET

Compositions of muffled glasses for the upper layer and the lower structural layer of composite glass-crystal cladding material based on phosphorus industry waste have been developed: phosphoric slag, phosphorite fines, coal dust and cullet.

Effects of cold rolling and heat treatment on microstructure and mechanical properties of 15Cr-15Ni ODS austenitic steel

Oxide dispersion strengthened (ODS) austenitic steels are considered as the promising candidate cladding materials application for advanced nuclear energy systems. However, the microstructure of ODS austenitic steels fabricated by mechanical alloying is usually not very homogeneous. Thermal mechanical treatment is an effective method for controlling microstructure of alloys. In this work, the effect of cold deformation and subsequent heat treatments on the improvement of microstructure homogeneous and mechanical property of a 15Cr-15Ni ODS austenitic steel was systemically investigated by means of electron backscatter diffraction, transmission electron microscopy and tensile test. Results show that the average grain size decreased and the distribution of grains was more homogeneous after optimized thermal mechanical treatment. The deformation of cold rolling and heat treatment temperatures shows obvious influence on the average size of dispersion particle, the proportion of high angle grain boundary, Schmidt factor and tensile property of 15Cr-15Ni ODS austenitic steel.

Assessing the Bioreceptivity of Biobased Cladding Materials

Materials exposed to the outdoors are prone to various deterioration processes. Architectural coatings are designed to protect surfaces against environmental and biotic degradation and to provide a decorative layer. The objective of this work was to examine the early colonisers on a diverse set of coated and non-coated biobased façade materials. A set of 33 wood-based cladding materials were exposed to four cardinal directions and monitored in outdoor conditions. The surfaces were sampled using a wet swab and plated on DG-18 agar, which prevents the growth of bacteria and limits the growth of fast-growing fungi. Pure cultures were then isolated and identified through PCR amplification and Sanger sequencing of specific DNA regions/genes. The response of cladding materials to weathering and fungal infestation was assessed. The proposed techniques enabled the identification of features that promote/inhibit fungal colonisation and revealed the preference of certain fungi for specific materials. Both the material type and the climate condition at the exposure site influence fungal colonisation. This study is a starting point for more exhaustive assays that aim to develop a novel coating system based on controlled and optimized fungal biofilm formation, and is proposed as a nature-inspired alternative for the protection of architectonic surfaces.

How to Make a City into a Firetrap: Relations of Land and Property in the UK's Cladding Scandal

AbstractDespite legislation banning combustible cladding materials after the 2017 Grenfell fire, at least 10,000 buildings were still awaiting remediation in 2022. This is in large part because fragmented ownership and management structures alongside the specificities of British property law produced a situation in which individual apartment owners (leaseholders) were liable for the costs of remediation rather than those who own the buildings (freeholders) or the developers who built them. Faced with unaffordable remediation bills, leaseholders became stuck in uninsurable, unsellable, potentially fire‐prone units. Through the case of a London housing block, we trace the relationship between the structure of landed property, value extraction, and the distribution of risk to understand how a significant portion of the UK's housing stock have remained firetraps. We argue that institutionalised value grabbing not only created the conditions of social murder but also became an obstacle to remediation, resulting in a politically charged “asset class struggle” over the way in which the structure of housing property and its capitalisation mediates social harm.