Coated System Research Articles

Semi-quantitative analysis on sea buckthorn phenolic-rich extract coating bone-like open porous NiTi-based alloy

This study investigates the feasibility of coating Ni–Ti alloy with sea buckthorn extract via a hydrothermal method for targeted delivery of beneficial phenolic compounds to bone tissue. The qualitative analysis confirmed the presence of flavonoids and tannins in sea buckthorn extract, supporting its osteogenic potential. The microhardness of the NiTi alloy substrate was suitable for biomedical applications, and successful coating was achieved without compromising its properties. NiTi alloy samples were coated with 18.1, 20.1, and 12.4 mg of extract, respectively. Comprehensive evaluations confirmed the successful integration of the extract onto the alloy's surface. The coated system exhibited sustained release properties over five days, with the highest release occurring on the first day (on average 32.1 % for the first peak and 72.1 % for the second peak), as determined by HPLC analysis. The findings demonstrate the potential of this novel approach in developing dual-functionality implants for bone health promotion. Overall, this study underscores the promising potential of Ni–Ti alloy coated with sea buckthorn extract as a targeted drug delivery system for bone tissue.

Environmental Impact Assessment of Anti-Corrosion Coating Life Cycle Processes for Marine Applications

In the present study, the life cycle assessment (LCA) of uncoated steel and alkyd-coated steel (using the sol–gel method) systems subjected to the marine atmosphere is performed to examine their environmental impacts. The LCA findings demonstrate a notable 46% reduction in the overall environmental impact of the coated system compared to the uncoated system. The findings of the sensitivity analysis indicate that a decreased mean time between repair and maintenance, along with an augmented quantity of coating, results in adverse environmental consequences. Furthermore, the LCA outcomes highlight the significant environmental impacts associated with 3-glycidyloxypropyltrimethoxysilane and n-propanol within the coated system. Hence, there is a need for the development of commercial coatings with bio-based products to develop a greener solution.

Corrosion studies on pulse reverse Ni–Mo coatings electrodeposited on Cu substrate

This study conducts a thorough analysis of Ni–Mo coatings electrodeposited on copper substrates, assessing the corrosion resistance of the coated system in a 3.5 M NaCl solution. It focuses on how deposition methods and anodic current densities affect both the coating's integrity and its ability to protect the substrate from corrosion. Three distinct techniques were employed to form Ni–Mo coatings: Direct Current (DC), Pulse Current (PC), and Pulse Reverse Current (PRC). Notably, coatings fabricated using the PRC method demonstrated significant morphological and corrosion behavioral variations compared to their DC and PC counterparts. Emphasis was placed on the role of porosity type and grain boundaries of the coatings, in addition to their composition, highlighting their considerable influence on corrosion dynamics. The standout performer was the one electrodeposited at the supreme anodic current density of 200 mA.cm⁻², exhibiting a composition of 25.2 wt% Mo, 57.4 wt% Ni, and 17.4 wt% O, and incorporating Ni–Mo alloy with oxide and hydroxide phases along with a small average grain size of less than 192 nm. The findings underscore the PRC method's efficacy in producing optimized Ni–Mo coatings, highlighting its broad potential for enhanced corrosion resistance applications.

The Use of Thin Films as Defect Sealants to Increase the Corrosion Resistance of Thermal Spray Coatings

Thermal spray-coated components are widely used as wear-resistant coatings in many applications. However, these coatings have high levels of discontinuities that affect the corrosion resistance of the coated system. To reduce this problem, these coatings are usually sealed with liquid sealants (metals, organic or inorganic). The aim of this work is to seal the surface discontinuities of thermal-sprayed coatings using PVD and/or ALD coatings. To this end, CrN (arc deposition PVD) and TiO2 (ALD) coatings were deposited on thermal-sprayed alumina coatings. The samples produced were then analysed in both cross-sectional and planar views to detect the possible permeation of the thin film coatings into the thermal spray defects. Rf-GDOES measurements were performed to detect the very thin ALD deposit on the surface. The corrosion resistance of the sealed coatings was verified with immersion tests, wherein the OCP was monitored for 24 h, and potentiodynamic tests were performed after 15 min and 24 h immersions. The results showed that the thin films were not able to block the permeation of corrosive media, but they could reduce the permeation of corrosive media with a beneficial behaviour on corrosion resistance.

Long-term clinical and radiological outcome of a cementless titanium-coated total knee arthroplasty system.

To ensure a high-quality standard, it is important to frequently evaluate different prostheses models to avoid prostheses with high failure rates. Thus, the aim of the study was to evaluate the long-term outcome of the uncemented titanium-coated total knee arthroplasty (TKA) system (Advanced Coated System (ACS) III, Implantcast, GERMANY). We hypothesized that the ACS III would have a similar performance as other cemented TKA systems. A total of 540 ACS III mobile-bearing knee joint prostheses were implanted in 495 patients. The visual analogue scale (VAS) score, Tegner activity score (TAS), knee society score (KSS), Western Ontario and McMaster (WOMAC) score, and the Short Form 12 (SF-12) score for the evaluation of quality of life (QoL) were taken after at least 9years of follow-up. In addition, we measured range of motion (ROM) and assessed potential sex differences. In addition, the survival analysis was calculated at a median follow-up of 16.7years. At the final follow-up, 142 patients had died, and 38 had been lost to follow-up. The rate of revision-free implant survival at 16.7years was 90.0% (95% CI 87.1-92.2%) and the rate of infection-free survival was 97.0% (IQR 95.2-98.2%). The reasons for revision surgery were aseptic loosening (32.9%), followed by infection (27.1%), inlay exchange (15.9%), and periprosthetic fractures (5.7%). At the clinical follow-up visit, the mean VAS score was 1.9 ± 1.9, the median TAS was 3 (IQR 2-4), and the mean KSS for pain and function were 83.5 ± 15.3 and 67.5 ± 25.2, respectively. The mean WOMAC score was 81.1 ± 14.9, and the median SF-12 scores for physical and mental health were 36.9 (IQR 29.8-45.1) and 55.8 (IQR 46.2-61.0), respectively. The mean knee flexion was 102.0° ± 15.4°. Male patients had better clinical outcome scores than female patients [SF-12 mental health score, p = 0.037; SF-12 physical health score, p = 0.032; KSS pain score (p < 0.001), and KSS functional score (p < 0.001)]. The ACS III TKA system is a suitable option for the treatment of end-stage osteoarthritis of the knee joint because of its adequate long-term survival. Our findings are in line with published data on similar TKA systems that have shown favourable clinical scores in males. Level III-Retrospective cohort study.

The effect of coated calcium carbonate using stearic acid on the recovered carbon black masterbatch in low-density polyethylene composites

Abstract This research focuses on recycling rubber tire waste through pyrolysis to produce recovered carbon black (rCB). The rCB is combined with recycled low-density polyethylene (rLDPE), calcium carbonate (CaCO3), fatty acid, metallic stearate, and polyethylene (PE) wax to create an rCB masterbatch for household packaging. Surface modification of CaCO3 particles using stearic acid improves the compatibility with LDPE. The study investigates mechanical properties, morphology, melt flow index (MFI), X-ray diffraction, and thermogravimetric analysis in three systems: uncoated, coated, and a hybrid combination of coated and uncoated CaCO3 in LDPE/rCB masterbatch composites. The coated system demonstrates higher mechanical properties and improved compatibility between CaCO3 and LDPE. All three systems exhibit enhanced thermal stability and MFI compared to virgin LDPE, with the coated system showing the most significant improvement. The study showcases the potential of LDPE/rCB masterbatch composites for household packaging, with the coated system displaying the optimum performance across various characteristics.

Should frying oil actively be removed using paper towel immediately after frying? A preliminary study using deep fried chicken as a model

The effect of active removal of oil with paper towel after frying was compared to an established oil reducing strategy using whey protein isolate (WPI) as a postbreading dip. Chicken pieces were battered, breaded with either crackermeal or Panko. Active removal of oil with paper towel after frying reduced oil in the samples of both coating systems that was comparable to the use of WPI. Instrumental analysis of texture and color indicates that active removal of oil with paper towel after frying did not affect color in either coating system and texture in the panko coated system. The study seems to confirm the previously untested conventional wisdom that active removal of oil after frying lowers the oil content of food.

Influence of substrate type on deformation specificity of soft film/hard substrate coated systems under nanomicroindentation

ABSTRACT This work is devoted to the study of the effect of a substrate chemical bonding type on the mechanical properties of coated systems (CSs) of a soft film/hard substrate type. The Cu/MgO and Cu/Si coated systems, as well as MgO and Si substrate crystals, which have similar hardness values but different types of chemical bonds, were studied. Various elastoplastic parameters were compared. The general and specific features of the deformation process under nanomicroindentation were identified. It has been established that general properties, such as ‘pop-in’, ‘pop-out’, ‘elbow’ effects, indentation size effect (ISE), are determined by the stress state created in the material during the indenter penetration and depend on the magnitude of the applied load and the film thickness. The specific properties, Young's modulus, hardness, relaxation parameters depend on the crystal structure and elastoplastic properties of the film and substrate material. The difference in the type of chemical bonding of the substrates, despite the close values of hardness, changes the elastoplastic properties and deformation mechanism of the composite structure as a whole, thereby expanding the possibility of creating new materials required for modern technology. Highlights Study of the effect of a substrate chemical bonding type on the mechanical properties of soft film/hard substrate (Cu/MgO, Cu/Si) coated systems. The difference in the type of chemical bonding of the substrates, despite the close values ⁣⁣of hardness, changes the elastoplastic properties and deformation mechanism of the composite structure as a whole.

Nanoscratch Testing of 3Al2O3·2SiO2 EBCs: Assessment of Induced Damage and Estimation of Adhesion Strength

In this study, the structural integrity of mullite (3Al2O3·2SiO2) films, deposited on silicon carbide (SiC) substrates using chemical vapor deposition (CVD), was investigated via increasing load nanoscratch tests. The films were configured by mullite columns of stoichiometric composition growing from a silica-rich layer in contact with the SiC substrate. Controlled damage was induced in the 3Al2O3·2SiO2 films at relatively low scratch loads. Radial and lateral cracking were applied until final delamination and repeated chipping were achieved as the load increased. The intrinsic integrity of the 3Al2O3∙2SiO2 film and the performance of the coated 3Al2O3·2SiO2/SiC system, regarded as a structural unit, were analyzed. With the aid of advanced characterization techniques at the surface and subsurface levels, the configuration and morphology of the damage induced in the coated system by the nanoscratch tests were characterized, and the scratch damage micromechanisms were identified. Finally, the adhesion of the film, in terms of energy of adhesion and interfacial fracture toughness, was determined using different models proposed in the literature. The results from this investigation contribute to the understanding of the mechanical performance and structural integrity of EBC/SiC-based systems, which over the past few years have increasingly been implemented in novel applications for gas turbines and aircraft engines.

Electrochemical Impedance Analysis for Corrosion Rate Monitoring of Sol-Gel Protective Coatings in Contact with Nitrate Molten Salts for CSP Applications.

The protective behaviour of ZrO2-3%molY2O3 sol-gel coatings, deposited with an immersion coating technique on 9Cr-1Mo P91 steel, was evaluated with corrosion monitoring sensors using the electrochemical impedance spectroscopy technique. The tests were carried out in contact with solar salt at 500 °C for a maximum of 2000 h. The results showed the highly protective behaviour of the coating, with the corrosion process in the coated system being controlled by the diffusion of charged particles through the protective layer. The coating acts by limiting the transport of ions and slowing down the corrosive process. The system allowed a reduction in the corrosion rate of uncoated P91 steel. The estimated corrosion rate of 22.62 μm·year-1 is lower than that accepted for in-service operations. The proposed ZrO2-3%molY2O3 sol-gel coatings are an option to mitigate the corrosion processes caused by the molten salts in concentrated solar power plants.

Enhancing the Oxidation Behavior of Zr-Modified Aluminide Coatings on Inconel 600 at Different Temperatures

In the recent search nickel superalloy Inconel 600 was coated with Zr-modified aluminide diffusion coating using pack cementation technique. Diffusion coating was done in a single step utilizing a conversion reaction of 10% Al, 2% ZrO2, 4% NaCl, and 84 percent Al2O3 (wt. percent ) and a simultaneous aluminizing-zirconizing process. The diffusion coating operations were performed in an argon environment at 1050 °C for 10 hours. The test of the isothermal oxidation in dry air was performed on the Inconel Alloy 600 (IA600) without and with Zr-modified aluminide coating for 800-1000 °C. The oxidation kinetic of IA600 and its coated system was found to follow the parabolic law. The activation energy is 243 kJ/mol. for the coated system and 457 kJ/mol. for the uncoated system. XRD analysis show that oxide phases are formed on an uncoated IA600 surface during most of the oxidation exposure conditions are NiO, Cr2O3, Fe2O3, NiCr2O4 and NiFe2O4, , whereas alumina scale is the major oxide that is obtained on the surface of coated samples.

Evaluation of the Fatigue Behaviour and Failure Mechanisms of 52100 Steel Coated with WIP-C1 (Ni/CrC) by Cold Spray

Cold spray technique has been major improved in the last decades, for studying new properties for metals and alloys of aluminum, copper, nickel, and titanium, as well as steels, stainless steel and other types of alloys. Cold sprayed Ni/CrC coatings have the potential to provide a barrier as well as improved protection to steels. Fatigue characteristics of 52100 steel coated with Ni/Chrome-Carbide (Ni/CrC) powder mixture by using cold gas dynamic spray are investigated. Fatigue samples were subjected to symmetrically alternating, axially applied cyclic fatigue loading until failure. The test was stopped if a sample survived more than 5 × 106 cycles at the applied stress. Fracture surfaces for each sample were examined to investigate the behaviour of the coating both at high stress levels and at a high number of stress cycles. Scanning electron microscopy was used to assess the damage in the interface of the two materials. Good fatigue behaviour of the coating material was observed, especially at low stresses and a high number of cycles. Details of the crack initiation region, the stable crack propagation region and the sudden crack expansion region are identified for each sample. In most of the samples, the initiation of the crack occurred on the surface of the base material and propagated into the coating material. The possible effects of coatings on the initial deterioration of the base material and the reduction of the lifespan of the coated system were also investigated. The aim of the paper was to study the interface between the base material and the coating material at the fatigue analysis for different stresses, highlighting the appearance of cracks and the number of breaking cycles required for each sample.

Size effects on high temperature oxidation of MCrAlY coatings processed via APS and HVOF depositions

The paper demonstrates how defects inherited from the deposition processes can severely impair the lifetime of MCrAlY coatings in service. The oxidation behavior of two NiCoCrAlY coatings was investigated at 1150 °C up to 500 h. The coatings had the same nominal composition but were processed by two different projection techniques: air plasma spray (APS) and high velocity oxy fuel (HVOF). Freestanding coating specimens were extracted from the coated system and thinned down to different thicknesses ranging from 520 to 15 μm in order to investigate size effects inherent to the oxidation response. The oxidation rate of the APS coating was found to be insensitive to the specimen thickness, while that of the HVOF coating increased with the specimen thickness, due to greater intersplat oxidation. APS specimens thinner than 60 μm experienced intrinsic chemical failure (InCF) due to Al consumption to form the Al2O3 scale. In comparison, HVOF specimens with a thickness of 367 μm were subject to InCF after 250–350 h oxidation. This first stage of InCF resulted in the formation of a Cr2O3 layer at the Al2O3/metal interface once Al activity in the MCrAlY coating was low enough to thermodynamically allow Cr2O3 to form. In addition, thick HVOF specimens developed mechanically induced chemical failure (MICF) resulting in the formation of (Ni,Co)(Cr,Al)2O4 spinels on top of the Al2O3 scale and within oxide intrusions. The occurrence of MICF was associated with the concomitant effects of Al consumption due to intrusive oxidation and the spallation of the external Al2O3 scale.

Evaluation of fretting wear damage on coated system using computer vision technique

Evaluation of fretting wear damage on coated system using computer vision technique

Recent advances in electroless nickel‑boron coatings

Electroless nickel‑boron coatings have been used in various industrial sectors for more than 40 years due to their excellent mechanical and tribological properties, that exceed those of hard chrome, with homogeneous surface finishing, and competitive corrosion resistance. Standard electroless nickel‑boron coatings are usually confined to use in niche applications such as saw blades, firearms, and valves in the oil and gas industry due to the presence of heavy metals from the stabilizing agent in the coated system. However, recent advances in technology have made it possible to remove heavy metals but also to improve the productivity and properties of the coatings, sometimes in a remarkable manner. This introduces the standard EN-B coatings and their properties and highlights the most recent improvements, variants in bath composition and process and applications of electroless nickel‑boron; such as the production of lead and thallium-free coatings, the effect of ultrasonics and surfactants, composite and multi-alloy coatings, but also innovative post-treatments to provide a wide panorama of the recent advances in the field. Finally, the review brings light to the new developments that are still necessary in the field to narrow the gap between research and industrial development and enlarge the niche area of utilization. • EN-B coatings present high hardness, making them excellent candidates for the replacement of hard chrome. • Removing heavy metal stabilizer from electroless nickel-boron opens new fields of applications such as automotive. • Use of ultrasound allows increasing the plating speed of electroless nickel-boron without losing in properties. • Properties of electroless nickel-boron coatings can be tuned by using composite, multilayers, and alloy coatings. • Bath replenishment and recycling are still limited, developing methods for sustaining plating bath life is required.

Effect of albumin coating on the magnetic behavior of Mn ferrite nanoclusters.

The effect of clustering induced by albumin coating on the magnetic behaviour of ultra-small MnFe2O4 nanoparticles has been systematically investigated and compared with that in pure Mn ferrite nanoparticle dense assembly, using a mesoscopic scale approach and numerical simulations reproducing the experimental findings well. Our results provide evidence that in the coated system, the interplay between intra-particle and intra-cluster exchange interactions strongly affects the exchange bias and coercive field values, with the dipolar interactions playing a minor role. Instead, the albumin coating does not affect the thermal stability of the observed superspin glass phase, the freezing temperature being similar in the coated and uncoated systems.

A review of coated nano- and micro-lattice materials

Emerging additive manufacturing methods have enabled the fabrication of novel 3D nano- and micro-architected lattice materials, allowing researchers to investigate previously unexplored phenomena and property spaces. This new class of materials, which are mainly made from polymers, can be further functionalized through the deposition of ceramic and metallic coatings opening up even more property spaces as a result of unprecedented mechanical behaviors and functionalities. By leveraging an expansive material workspace, architectural hierarchy, and materials size effects, these structures have been shown to achieve high strength, low density, and exceptional recoverability with promise in applications ranging from cell and tissue growth to energy storage. This review addresses the current development space of coated nano- and micro-lattice structures and highlights important considerations that influence their behavior and functionality. Discussing deposition methods and present challenges, this review offers foundational insight on generating new advanced coated lattice systems.

Coating Lacticaseibacillus rhamnosus GG in Alginate Systems: an Emerging Strategy Towards Improved Viability in Orange Juice

Fruit juices are successfully proposed as suitable probiotic vehicles, but researchers’ efforts should be developed to avoid effects of bacteria overgrowing on sensory and nutritional cues of final products and to preserve viability of probiotic bacteria during storage. In the present study, encapsulation of Lacticaseibacillus rhamnosus GG strain in alginate systems was performed through ionotropic gelation technology. The alginate systems were optimized by using Box-Behnken Design to investigate the influence of three independent variables at three different levels: particle mean size and polydispersity index. The optimized probiotic-loaded alginate particles were added to orange juice samples. The viability of the probiotic strain, both as free and microencapsulated, was evaluated in orange juice stored at 5°C for 35 days. Morphology and size of probiotic-loaded alginate particles were found suitable for incorporation into juice. TEM analysis revealed that unloaded systems were clustered as nanoparticles (CL_NP), while the loaded sample appeared as a coated system (Coated_LGG). Microbiological evaluation revealed that the encapsulation assured the survival of Coated_LGG, with a reduction of less than 1-unit log in cellular density after 35 days of refrigerated storage in orange juice. Results indicated that the encapsulated bacteria did not affect the macroscopic properties neither the microbiological characteristic of orange juice; thus, it can be proposed as functional food.

Anisotropic crack propagation behavior for the silicon‐bond coat layer in a multilayer coated system

AbstractThis study sought to examine the relationship between the degradation mechanism, thermal stress, and crack propagation behavior in environmental barrier coating (EBC) systems. An EBC system composed of a mullite topcoat (TC), Si‐bond coat (BC), and SiC substrate was prepared by atmospheric plasma spraying. Heat exposure tests were conducted to evaluate the microstructure of the EBC system at 1300°C for 1, 10, 50, and 100 h. The fracture resistance of the Si BC for the in‐plane (direction parallel to each layer, 0.4–0.6 MP) and through‐thickness directions (direction from the TC to substrate, 1.7–2.1 MP) differed because a thermal compressive stress was induced for the in‐plane direction owing to the mismatch of the thermal expansion coefficients for each layer, which acted as a barrier for crack propagation. However, cracks tended to propagate in the in‐plane direction because they were not affected by the in‐plane compressive stress. These results clearly showed that Si BC exhibited in‐plane anisotropy and crack propagation after heat exposure, which were the major sources of delamination of the EBC system.

Evaluation of fretting wear damage on coated system using computer vision technique

Evaluation of fretting wear damage on coated system using computer vision technique