Metallic Coatings Research Articles

Effect of TMAB and ZrC concentration on mechanical and morphological properties of Ni–B/ZrC composite electrodeposition

Abstract Coating of metal or nonmetallic materials made conductive can be achieved by electrodeposition method. Metals with low conductivity and cost, such as copper or steel, can be coated with materials with higher hardness, corrosion, and wear resistance, such as nickel and boron, and can meet the relevant requirements according to their usage areas. In this study, the impact of trimethylamine borane complex (TMAB) and zirconium carbide (ZrC) contents added to the bath concentrate in the Ni–B/ZrC composite coating applied on copper on the surface properties of electroplating was investigated. Electroplated specimens were examined with regard to mechanical, morphological, and corrosion resistance. The highest microhardness value was obtained in the coatings obtained with 6 g L−1 TMAB and 4 g L−1 ZrC bath concentration, and this value was found to be 1,020.4 H V. When examined in terms of coating morphology, it was seen that as the amount of TMAB increased, the ZrC content decreased over time. In the nanocomposite coating with 4 g L−1 ZrC concentration, which showed the best corrosion performance, the corrosion current decreased by 70 % compared to the Ni–B alloy.

Review of The Impact Of Hydrogen-Containing Fuels On Gas Turbine Hot-Section Materials

Abstract In an effort to achieve worldwide decarbonization goals, a range of low-carbon fuels is being proposed for use in power-generation gas turbines. Two promising fuels are hydrogen and ammonia, which do not produce any CO2 upon combustion. While the use cases of these fuels differ, each has the potential to reduce the carbon intensity of power generation as compared to the current use of natural gas and fuel oil. Many studies have considered the impact that these fuels will have on combustion stability and emissions, as well as other practical considerations like balance of plant. However, potential challenges for the material systems in these engines, particularly high-temperature metal alloys and coatings, have not been sufficiently considered in preparation for the introduction of these fuels. The goal of this paper is to provide a review of the potential material issues associated with implementation of these hydrogen-containing fuels, with a focus on materials in the hot section of existing power-generation gas turbines. To date, relatively little research has considered these material issues at realistic gas turbine conditions, resulting in a need for new research. This paper provides a review of the literature, first-order analyses of the magnitude of potential issues, and avenues for research to facilitate the safe and reliable introduction of these fuels in power-generation gas turbines.

Influence of hydrogen content in tokamak scrape-off-layer on performance of lithium divertor

Abstract Self-replenishing liquid metal coatings are considered as a perspective divertor design able to withstand challenging particle and power loads of a fusion tokamak-reactor. Numerical modeling of the scrape-of-layer (SOL) plasma with advanced 2D codes, such as SOLPS, is necessary for developing of the ‘liquid-metal’ divertor. In this work we report on upgraded version of SOLPS 4.3 code liquid metal erosion module implemented earlier in our group and present results of simulations of T-15MD tokamak with Li-covered divertor plates. The erosion model includes all main processes Li erosion, i.e. physical sputtering, thermal sputtering, evaporation, and prompt redeposition. Unlike some other available implementations, Li atoms are considered in kinetic approximation in our version. A detailed analysis of Li erosion and flow in T-15MD configuration for various powers (6–12 MW) and H content in the SOL is presented. It is shown that the most of eroded Li particles are redeposited on the divertor targets, however, in some regimes absolute Li flow from the divertor is still large and might lead to significant main plasma dilution with Li. Vapor shielding effect is pronounced on both divertor targets in the most reasonable regimes providing low peak heat flux values at the target plates, less than 10 MW m−2. The target erosion rate and surface temperatures are within limits of the most target designs. Moreover, in strongly shielded cases the target temperature can be even lower than the Li melting temperature meaning that external heating is required to keep Li flowing. Sensitivity analysis shows that our results are most sensitive to the target heat conduction parameters, i.e. the target thickness, outer surface temperature. It means that controlling the target cooling rate can be a useful tool for controlling the liquid Li divertor regime. Variation of the Li erosion rate parameters has little effect on the divertor performance.

Correction: Comparison of Tribological Behavior of Hard Faced Fe-Based Metallic Composite Coatings Sprayed Using HVOF

Correction: Comparison of Tribological Behavior of Hard Faced Fe-Based Metallic Composite Coatings Sprayed Using HVOF

Electrochemical Corrosion Resistance of Al2O3–YSZ Coatings on Steel Substrates

Ceramic materials as coatings are known to have very good corrosion resistance properties compared to metallic or organic coatings, regardless of environmental conditions. The following samples were used for the experiments: an initial steel substrate and Al2O3 + YSZ (12.5%; 25% and 37.5% wt) atmospheric plasma spray-coated samples. The open circuit potential showed similar average values for all samples coated with ceramic layers, which were slightly higher than the potential of the original uncoated sample. The corrosion current densities (icorr) of all plasma jet sputter-coated systems were very similar and significantly lower than those of the original material. Corrosion rates were much lower in the coated systems due to the chemical inertness of the ceramic coatings, particularly alumina- and zirconia-based coatings. It was observed that ceramic layers improve the corrosion resistance of the metallic material, especially at higher percentages of YSZ in the plasma spray-deposited complex layer. The porosity of the sputter-deposited layers reduced their corrosion resistance due to the contact between the electrolyte solution and the metal substrate created by the interconnection of the pores. The complex equivalent electrical circuit chosen for the analysis of the values led to results in accordance with the experimental parameters.

Zr-Based Thin Film Metallic Glasses As High-Efficiency Materials for Electrocatalysis of the Hydrogen Evolution Reaction

The production of hydrogen through water electrolysis is a major limiting step in the implementation of hydrogen-based energy storage. Currently used materials for catalyzing the hydrogen evolution reaction require large overpotentials, reducing the efficiency of hydrogen production. Metallic glasses are of interest for use in electrocatalysis due to their high activity and diversity of catalytic sites. However, only a small selection of metallic glass compositions can be manufactured into bulk parts, necessitating the use of metallic glass coatings. In this research, a Zr-based metallic glass was produced as a thin film using sputtering deposition. Combinatorial co-sputtering was used to produce a library of quaternary Zr-based metallic glasses to enable high-throughput characterization of the anode material and electrochemical testing. Metallic glass surfaces were characterized prior to and after electrochemical testing using a range of techniques to explore the physiochemical properties of the catalytic surface. Nano-structured metallic glass coatings are a promising material for catalysis of the hydrogen evolution reaction. This work is funded by ARPA-e under DE-AR0001697. JRH is funded as a fellow under the NSF GRFP.

Mechanical, Tribological, and Corrosion Resistance Properties of (TiAlxCrNbY)Ny High-Entropy Coatings Synthesized Through Hybrid Reactive Magnetron Sputtering

This study investigates the effects of aluminum and nitrogen content on the microstructure, mechanical properties, and tribological performance of high-entropy coatings based on (TiCrAlxNbY)Ny systems. Using a hybrid magnetron sputtering technique, both metallic and nitride coatings were synthesized and evaluated. Increasing the aluminum concentration led to a transition from a crystalline to a nanocrystalline and nearly amorphous (NC/A) structure, with the TiAl0.5CrNbY sample (11.8% Al) exhibiting the best balance of hardness (6.8 GPa), elastic modulus (87.1 GPa), and coefficient of friction (0.64). The addition of nitrogen further enhanced these properties, transitioning the coatings to a denser fine-grained FCC structure. The HN2 sample (45.8% nitrogen) displayed the highest hardness (21.8 GPa) but increased brittleness, while the HN1 sample (32.9% nitrogen) provided an optimal balance of hardness (14.3 GPa), elastic modulus (127.5 GPa), coefficient of friction (0.60), and wear resistance (21.2 × 10−6 mm3/Nm). Electrochemical impedance spectroscopy revealed improved corrosion resistance for the HN1 sample due to its dense microstructure. Overall, the (TiAl0.5CrNbY)N0.5 coating achieved the best performance for friction applications, such as break and clutch systems, requiring high coefficients of friction, high wear resistance, and durability.

Porous transport layers with low Pt loading having Nb–Ta alloy as interlayer for proton exchange membrane water electrolyzers

Titanium (Ti), commercially used as substrate for porous transport layers (PTLs) in proton exchange membrane water electrolyzers (PEMWEs), tends to form passivating oxide layer, increasing interfacial contact resistance (ICR) and reducing performance and durability; practice of using precious metal coatings for mitigation significantly increases costs. This study investigates niobium-tantalum (Nb–Ta) alloys as cost-effective interlayer coatings on Ti-felt to reduce precious metal loading. Nb–Ta coated samples significantly increase corrosion potential, lower current densities by 3–4 orders of magnitude, reduce ICR by 3.5 times, and improve durability. The best performance sample with an ultra-low amount of platinum, shows 8 times greater durability, 12.5% reduction in ohmic resistance and 28% increase in current density at +2.0 V than the commercial PTL in a single cell stack. Improved contact angle, electrical, and thermal conductivity highlight Nb–Ta interlayer coatings for PTLs, offering a cost-effective strategy to enhance PEMWE performance and durability for green hydrogen production.

Comparison of Tribological Behavior of Hard Faced Fe-Based Metallic Composite Coatings Sprayed Using HVOF

Comparison of Tribological Behavior of Hard Faced Fe-Based Metallic Composite Coatings Sprayed Using HVOF

Stabilizing Metal Coating on Flexible Devices by Ultrathin Protein Nanofilms.

The significant modulus difference between a metal coating and a polymer substrate leads to interface mismatches, seriously affecting the stability of flexible devices. Therefore, enhancing the adhesion stability of a metal layer on an inert polymer substrate to prevent delamination becomes a key challenge. Herein, an ultrathin protein nanofilm (UPN), synthesized by disulfide-bond-reducing protein aggregation, is proposed as a strong adhesive layer to enhance adhesion between polymer substrate and metal coating. Unlike traditional biopolymer adhesives with micrometer-scale thicknesses, the UPN layer is minimized to nanometer/single-molecular scale. Such UPN thereby effectively enhances the interfacial adhesive strength and reduces the cohesion contribution in the entire adhesion system by directly connecting two interfaces with a nearly single-molecular thickness. Using UPN as the adhesive layer, a multifunctional metal coating could be reliably adhered on flexible polymer substrates by ion sputtering, delivering unprecedented adhesion stability even under repetitive mechanical deformation. Applications of this design include reversible transparency control, tension-responsive encryption, reusable optical sensing, and wearable capacitive touch sensors. This work highlights UPN's potential to create strong bonding strength between flexible polymers and metal coatings, offering a biocompatible solution with high surface activity and low cohesion, facilitating the development of hybrid devices with stable metal nano-coating.

Pore defect and corrosion behavior of HVAF-sprayed Co21Fe14Ni8Cr16Mo16C15B10 high entropy metallic glass coatings

Pore defect is a primary bottleneck limiting corrosion resistance of the coatings. The relationship between porosity and corrosion behaviors of HVAF-sprayed Co21Fe14Ni8Cr16Mo16C15B10 high entropy metallic glass (HE-MG) coatings was investigated by 3D XRT, XPS, SKPFM and SVET techniques. The potential difference between pores and surrounding regions expedites corrosion tendency. The corrosion current density of the coating and concentration of defects in passivation film increase as a function of porosity, thereby degrading corrosion resistance. The lowest porosity coating displays exceptional anti-corrosion due to compact films enriched with Cr2O3 and Mo4+ oxides. These findings provide valuable insights for designing corrosion-resistance coatings.

Biological testing of titanium-containing implants with noble metal coatings in an in vivo experiment

The aim of study is to conduct in vivo biological testing of titanium nickelide samples modifed with Ag/Pt or AuAg/Pt flm heterostructures in comparison with the bare carrier.Material and Methods. Titanium nickelide plates modifed with flm heterostructures made of noble metals and the laboratory mini-pigs used for in vivo tests were the objects of the study. To form flm structures on titanium nickelide samples, the physical gasphase deposition methods: ion plasma deposition (IPD) and thermal (PVD) sputtering were used. The Ag/ Pt or AuAg/Pt heterostructures were characterized by X-ray diffraction and scanning microscopy methods.Results. The biocompatibility of implants before (TiNi, control) and after (Ag/Pt/TiNi and AuAg/Pt/TiNi) modifcation with flm heterostructures was tested in in-vivo experiments on a laboratory animal (mini-pig). General toxic reactions of the body to the injected samples were absent. A comparative macroscopic and histological analysis of the condition of peri-implant tissues after 39 days of implantation was performed. The connective tissue capsule around the TiNi sample revealed the presence of a certain number of lymphocytes, eosinophils and macrophages, but these indicators decrease in the order of TiNi > AuAg/Pt/TiNi > Ag/Pt/TiNi.Conclusion. The positive effect of modifying the titanium nickelide surfaces with noble metal heterostructures on the biocompatibility of metal implants was demonstrated in an in vivo experiment.

Jc(B) transformer rectifier flux pump optimisation via simulation

Abstract Superconducting power supplies commonly known as flux pumps are becoming viable products in various industries. In this work we investigate magnetically switched ( J c ( B ) ) half-wave transformer rectifier flux pumps (TRFPs) via a simulation previously validated against an experimental system. Upgrades to the model are introduced, namely the transition to a fully hysteretic transformer reluctance model and the introduction of a conduction cooling thermal model. The conduction cooling model allows direct comparison between liquid cryogen and conduction cooled systems, highlighting the distinct variations in response. This study focuses on parameter sweeps over some of the most important aspects of a TRFP such as; input power, cooling paths and switch length. The findings from these variable sweeps shed light on how to best design the different aspects of a TRFP for most applications and the conclusions drawn throughout this work can be applied to most TRFP types. Some of the major findings from this work are; i. the need for dedicated cooling busses in TRFP switches, ii. that increased switch lengths increase voltage generation but negatively impact cooling effectiveness iii. that the reduction of the metallic coatings surrounding commercial coated conductors results in larger switch voltages.

AkzoNobel developed a particle technology for metallic effect powder coatings

AkzoNobel developed a particle technology for metallic effect powder coatings

Performance of nonprecious metal-filled Pt-based coating of Ti bipolar plates for proton exchange membrane water electrolyzer

In proton exchange membrane water electrolyzer (PEMWE), coatings based on Pt demonstrate outstanding performance; however, their elevated cost restricts broader utilization. The application of nonprecious metal coatings frequently compromises either conductivity or corrosion resistance. In this investigation, a range of nonprecious metal-filled Pt-based coatings was fabricated on TA1 through magnetron sputtering. The application of thinner coatings and filler materials led to a significant reduction in Pt usage to 0.051 mg cm−2. The conductive Pt surface, along with the wire-like Pt structure integrated within the coating, contributes to remarkable electronic transmission capabilities. The dense and stable oxides generated by the filler metals ensure excellent corrosion resistance. Following a 48-h durability assessment, the application of the coating decreased the interfacial contact resistance of the Ti plate from 90.5 mΩ cm2 to 2.48 mΩ cm2, while the dissolution of Ti ions in the corrosive solution reduced from 13.45 ppb to 0.53 ppb. This effective nonprecious metal-filled Pt-based coating presents a novel strategy for minimizing the cost associated with PEMWE bipolar plates.

Bi-metallic electrochemical deposition on 3D pyrolytic carbon architectures for potential application in hydrogen evolution reaction

ABSTRACT 3D printing has emerged as a highly efficient process for fabricating electrodes in hydrogen evolution through water splitting, whereas metals are the most popular choice of materials in hydrogen evolution reactions (HER) due to their catalytic activity. However, current 3D printing solutions face challenges, including high cost, low surface area, and sub-optimal performance. In this work, we introduce metal-deposited 3D printed pyrolytic carbon (PyC) as a facile and cost-effective HER electrode. We adopt an integrated approach of resin 3D printing, pyrolysis, and electrochemical metal deposition. 3D printing of a resin and its subsequent pyrolysis led to 3D complex architectures of the conductive substrate, facilitating the electrochemical metal deposition and leading to layered 3D metal architecture. Both monolayers of metals (such as copper and nickel) and bi-metallic 3D PyC structures are demonstrated. Each metal layer thickness ranges from 6 to10 µm. The metal coatings, particularly the bi-metallic configurations, result in achieving significantly higher mechanical properties under compressive loading and improved electrical properties due to the synergistic contributions from each metal counterpart. The metalized PyC structures are further demonstrated for HER catalysts, contributing to the development of highly efficient and durable catalyst systems for hydrogen production. Among the materials studied here, Ni@Cu bimetallic 3D PyC electrodes are particularly well-suited, demonstrating a low HER overpotential value of 264 mV (100 mA/cm2, KOH (1 M)) with corresponding Tafel slopes of 107 mV/dec, with exceptional stability during a 10 h operation at a high applied current of −50 mA/cm2.

Influence of Ti Layers on the Efficiency of Solar Cells and the Reduction of Heat Transfer in Building-Integrated Photovoltaics

This study examined the potential application of metallic coatings to mitigate the adverse effects of ultraviolet (UV) and infrared (IR) light on photovoltaic modules. Titanium coatings were applied on low-iron glass surfaces using magnetron sputtering at powers of 1000, 1250, 1500, 1750, 2000, and 2500 W. The module with uncoated glass served as a reference. The Ti layer thickness varied from 7 nm to 20 nm. Transmittance and reflectance spectra were used to calculate visible light transmittance Lt, UV light transmittance Ltuv, solar transmittance g, and visible light reflectance Lr. The obtained parameters indicated that the thinnest Ti layer (1000 W) coating did not significantly affect light transmittance, but thicker layers did, altering the Lt, g, and Lr factors. However, every sample noticeably changed Ltuv, probably due to the natural formation of a UV-reflective thin TiO2 layer. The differences in fill factor (FF) were minimal, but thicker coatings resulted in lower open-circuit voltages (Uoc) and short-circuit currents (Isc), leading to a reduction in power conversion efficiency (PCE). Notably, a Ti coating deposited at 2500 W reduced the power of the photovoltaic module by 78% compared to the uncoated sample but may protect modules against the unwanted effects of overheating.

ALd of Metal Fluorides–Potential Applications and Current State

AbstractMetal fluoride thin films are important materials in a multitude of applications. Currently, they are mostly used in optics, but their potential in energy harvesting and storage is recognized as well. Atomic layer deposition (ALD) is an advanced thin film deposition method that has an ever‐increasing role in microelectronics. The assets of ALD are its capability to produce uniform, stoichiometric, and pure films with precise thickness control even on top of complicated structures, such as high aspect ratio trenches. These characteristics can be beneficial in applications of metal fluoride thin films but so far ALD of metal fluorides has remained much less studied and used than ALD of metal oxides, nitrides, sulfides, and pure metals. This review aims to motivate research on ALD of metal fluorides by surveying potential applications for ALD metal fluoride thin films and coatings. The basics of luminescent applications, antireflection coatings, and lithium‐ion batteries will be discussed. Next, the fundamentals of ALD will be presented followed by a comprehensive summary of the metal fluoride ALD processes published so far.

The Effect of Shot Blasting Abrasive Particles on the Microstructure of Thermal Barrier Coatings Containing Ni-Based Superalloy

Grit particles remaining on the substrate surface after grit blasting are generally considered to impair the thermal performance of thermal barrier coatings (TBCs). However, the specific mechanisms by which these particles degrade the multilayer structure of TBCs during thermal cycling have not yet been fully elucidated. In this study, the superalloy substrate was grit-blasted using various processing parameters, followed by the deposition of thermal barrier coatings (TBCs) consisting of a metallic bond coat (BC) and a ceramic top coat (TC). After thermal shock tests, local thinning or discontinuities in the thermally grown oxide (TGO) layer were observed in TBCs where large grit particles were embedded at the BC/substrate interface. Moreover, cracks originated at the concave positions of the TGO layer and propagated vertically towards BC; these cracks may be associated with additional stress imposed by the foreign grit particles during thermal cycling. At the BC/substrate interface, crack origins were observed in the vicinity of large grit particles (~50 μm).

Significantly enhanced corrosion resistance for Fe-based amorphous coatings via sealing treatment: Based on hybridisation and superhydrophobicity strategy

Based on the synergistic effect of hybridisation-superhydrophobicity, a simple and facile spraying method was used to achieve efficient sealing of Fe-based amorphous metallic coatings. In this paper, we employed rare-earth neodymium salts as inorganic sealant raw materials and loaded low surface energy fluorosilanes into epoxy resins to act as organic sealant raw materials. The surface structure and chemical composition of the sealing coatings were systematically characterised. The sealing mechanism as well as the anti-corrosion mechanism of the coating were investigated intensively. The results indicate that the superior corrosion resistance and self-cleaning ability of the sealed coating stems from the inorganic–organic-complex trinity effect: the corrosion inhibition effect of Nd oxide deposited during the inorganic sealing process, the shielding effect of the resin in the organic sealing, and the cross-linking and superhydrophobicity behaviour (liquid repellency effect) of the FDTES-Nd3+-Fe2+ complexes formed on the surface of the coating. This work provides valuable guidelines and insights for the design of subsequent corrosion-resistant and sealing coating.