Multicomponent Coatings Research Articles

Enhanced bioactivity and mechanical properties of silicon-infused titanium oxide coatings formed by micro-arc oxidation on selective laser melted Ti13Nb13Zr alloy

The titanium scaffolds and surface-porous implants are manufactured by fast and cheap additive methods such as selective laser melting (SLM). The obtained irregularity and relative biological inertness of the titanium need proper surface modification. This research is aimed at forming bioactive multicomponent oxide coatings by micro-arc oxidation (MAO) at different process parameters on the selective laser-melted Ti13Zr13Nb alloy. The MAO process was carried out in a base solution containing 0.15 mol/L Ca and 0.1 mol/L GP, with different amounts of metasilicate added under two different applied voltages. Scanning electron microscopy, atomic force microscopy, X-ray electron diffraction spectroscopy, nanomechanical and nano scratch tests, water contact angle measurements, phosphate deposition observed in long-term immersion tests, and biological LDH and MTT assays were performed. The results showed that the coating microstructure, morphology, and properties were significantly dependent on process parameters. In particular, the metasilicate addition and its rising content in the electrolyte resulted in the higher development of the surface followed by better viability of osteoblasts at no necrosis, with no negative change in the other parameters, usually close to those obtained on silicon-free coatings. The obtained results prove that the addition of silicon to the electrolyte at the partial expense of calcium can be favorable for long-term titanium implants made by selective laser melting.

Research, Development and Implementation of Methods for Determining Surface Density and Mass Fraction of Elements for Multilayer and Multicomponent Coatings by X-Ray Fluorescence Method

Metal coatings provide products with the necessary technical characteristics; in particular, they increase corrosion resistance and protect against mechanical abrasion. The application of metal coatings is a promising direction and is widely used in mechanical engineering, metallurgy, and other industries. Therefore, studying the properties and improving the technology of applying metal coatings is a significant and sought-after line of activity for metrology researchers. The needs of industry in the field of monitoring the parameters of single-layer and single-component coatings in the Russian Federation are fully satisfied. At the beginning of this study, the Federal Information Fund for Ensuring the Uniformity of Measurements provided a comprehensive list of reference materials of surface density and thickness of single-layer onecomponent coatings that were tested using the State Primary Standard for units of surface density and mass fraction of elements in coatings GET 168-2015. The needs for testing, verification, and calibration of instruments for measuring surface density, thickness, and chemical composition of multilayer and multicomponent coatings remained not fully met, which became the starting point for this research.The research presented in the article was carried out in order to develop methods for determining the surface density and mass fraction of elements for multilayer and multicomponent coatings on GET 168-2015. At the same time, the problem of developing a set of reference materials of surface density and mass fraction of elements in two-layer and two-component coatings for metrological support of the corresponding measuring instruments was solved.The article fully reveals the content of the work to improve metrological support for measuring surface density, thickness, and mass fraction of elements in coatings, taking into account the needs of industry in the field of monitoring coating parameters and the variety of measurement tasks that are constantly expanding.

The Influence of Bias Voltage on the Structure and Properties of TiZrNbMo Coating Deposited by Magnetron Sputtering

TiZrNbMo coatings have been deposited using the direct current pulsed magnetron sputtering method in an argon atmosphere. The synthesis processes have been conducted under various process parameters. The structure (chemical and phase composition) and mechanical properties of the obtained multicomponent coatings are investigated as a function of plasma modulation frequency (10 Hz and 1000 Hz) and substrate bias (0 to −150 V). It is the case that an increase in the substrate bias decreases the deposition rate and alters the coating’s chemical composition. The latter leads to a Ti concentration decrease and a simultaneous increase in Mo and Nb concentrations in the final coating material. X-ray diffraction measurements indicate a single-phase BCC structure, with grain size decreasing as substrate bias increases. This ultimately forms an amorphous–nanocrystalline structure at −150 V. The mechanical properties of the multicomponent TiZrNbMo coatings have been determined using the nanoindentation method. The maximum values of hardness (13.45 GPa) and elastic modulus (188.6 GPa) are achieved at a substrate bias of −150 V. We also show that the minimum elastic modulus (41.8 GPa) is achieved at an intermediate substrate bias of −100 V.

In-situ preparation and ablative resistance of multicomponent refractory carbide ceramic gradient coatings

In this work, the gradient multicomponent carbide ceramic coatings were prepared in-situ on graphite matrix using the molten salt method, and their high temperature ablation resistance was investigated. Our results demonstrate the successful preparation of (HfTi)C, (HfTiZr)C, and (HfTiZr)C–TaC ceramic coatings with a gradient distribution on the graphite matrix by altering the types of raw materials. Thermodynamic calculations and analyses indicate that the smaller the Gibbs free energy gap between different carbides, the easier the solid solution multicomponent ceramic coating is formed. After 200 s of oxy-acetylene torch ablation, it was observed that the (HfTi)C, (HfTiZr)C, and (HfTiZr)C–TaC coatings effectively protected the graphite matrix with mass ablation rates of 6.47 mg s−1, 0.61 mg s−1, and 0.51 mg s−1, respectively. The low mass loss of (HfTiZr)C and (HfTiZr)C–TaC coatings can be attributed to the synergistic protective effect of different oxides formed by oxidation of different elements.

High-Entropy Alloy Activating Laves-Phase Network for Multi-Component Metallic Coatings with High Hardness.

The low hardness and poor wear resistance of laser-cladding 316L stainless steel impose significant constraints on its practical applications. In this study, a strategy for strengthening laser-cladding 316L stainless steel with WMoTaNb refractory high-entropy alloy as a reinforcement material is proposed. The results confirm that the coating primarily comprises a body-centered cubic (BCC) Fe-based solid solution, a network-distributed hexagonal Fe2X (X = W, Mo, Ta, and Nb) Laves phase, and a diffusely distributed face-centered cubic (FCC) (Ta, Nb)C phase. The Fe-based solid solution distributes along columnar and fine dendrites, while the Laves phase and (Ta, Nb)C phase are in the inter-dendrites. The presence of a significant number of network Laves phases exhibiting high strength and hardness is the primary factor contributing to the enhancement of coating microhardness. The hardness of the composite coating is increased by nearly twice compared to that of the 316L coating, resulting in an improved wear resistance. The present work can shed light on designing and fabricating 316L stainless steel coating with enhanced hardness and wear resistance.

Investigation on corrosion resistance of electroless Ni-W-P coatings co-deposited with SiO2 nanoparticles

The corrosion of materials in sea environment are generally caused by salt spray, tidal action and adhesion of marine organisms. It is necessary to ensure the materials possess the required strength and good corrosion resistance during operation. Although the existing Ni-W-P electroless plating can provide a certain degree of corrosion protection, its corrosion resistance is still limited under harsh marine condition. SiO2 nanoparticles have received extensive concern due to their excellent corrosion resistance, which has been considered as potential candidates for enhancing corrosion resistance in multicomponent electroless coatings. In this study, the electroless Ni-W-P coatings with SiO2 nanoparticles co-deposition on the Q235 substrate was prepared. The coating was characterized through scanning electron microscopy (SEM), x-ray diffraction (XRD), polarization techniques, and electrochemical impedance spectroscopy (EIS). As a result, the Ni-W-P coating co-deposited with SiO2 nanoparticles demonstrates superior corrosion resistance compared to the pure Ni-W-P coating. The surface of SiO2 nanoparticles contain three distinct bonded hydroxyl functional groups, which can influence the ionic reaction in the plating solution and the deposition of elements in the coating. After modified by PVA, it can be uniformly dispersed in the coating, and the composite coating with SiO2 nanoparticles co-deposited is transformed into a nanocrystalline structure. The even distribution of SiO2 nanoparticles fill the defects within the coating, leading to a reduction in porosity, permeability, and susceptibility to penetration of corrosive media. Concurrently, the nanoparticles facilitate surface passivation, forming a stable interface with substrate and coating that inhibits electrochemical reactions and diminishes the rate of self-corrosion reactions. The good and stable corrosion resistance is achieved at the SiO2 concentration of 9 g l−1 and PVA concentration of 1.08 g l−1. These findings offer valuable insights for addressing corrosion challenges in the field of marine engineering.

Oxidation and hot corrosion behavior of multicomponent coatings produced by atmospheric plasma spray

Oxidation and hot corrosion behavior of multicomponent coatings produced by atmospheric plasma spray

Nanoarchitectonics of Bactericidal Coatings Based on CaCO3-Nanosilver Hybrids.

Antimicrobial coatings provide protection against microbes colonization on surfaces. This can prevent the stabilization and proliferation of microorganisms. The ever-increasing levels of microbial resistance to antimicrobials are urging the development of alternative types of compounds that are potent across broad spectra of microorganisms and target different pathways. This will help to slow down the development of resistance and ideally halt it. The development of composite antimicrobial coatings (CACs) that can host and protect various antimicrobial agents and release them on demand is an approach to address this urgent need. In this work, new CACs based on microsized hybrids of calcium carbonate (CaCO3) and silver nanoparticles (AgNPs) were designed using a drop-casting technique. Polyvinylpyrrolidone and mucin were used as additives. The CaCO3/AgNPs hybrids contributed to endowing colloidal stability to the AgNPs and controlling their release, thereby ensuring the antibacterial activity of the coatings. Moreover, the additives PVP and mucin served as a matrix to (i) control the distribution of the hybrids, (ii) ensure mechanical integrity, and (iii) prevent the undesired release of AgNPs. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) techniques were used to characterize the 15 μm thick CAC. The antibacterial activity was determined against Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA), and Pseudomonas aeruginosa, three bacteria responsible for many healthcare infections. Antibacterial performance of the hybrids was demonstrated at concentrations between 15 and 30 μg/cm2. Unloaded CaCO3 also presented bactericidal properties against MRSA. In vitro cytotoxicity tests demonstrated that the hybrids at bactericidal concentrations did not affect human dermal fibroblasts and human mesenchymal stem cell viability. In conclusion, this work presents a simple approach for the design and testing of advanced multicomponent and functional antimicrobial coatings that can protect active agents and release them on demand.

Multicomponent (Hf-Zr-Ta)B2 coatings for carbon/carbon composites and structural optimization enabling superior ablation resistance

Multicomponent (Hf-Zr-Ta)B2 potentially provides improved ablation resistance compared with silicon-based ceramics. Here we deposited (Hf0.5–x/2Zr0.5–x/2Tax)B2 (x = 0, 0.1, and 0.2) coatings onto C/C composites, and investigated their ablation behaviors under an oxyacetylene torch with a heat flux of 2.4 MW m–2. It was observed that the x = 0.1 oxide scale bulged but was denser, and the x = 0.2 oxide scale was blown away due to the formation of excessive liquid. Based on these findings, we further developed a duplex (Hf-Zr-Ta)B2 coating that showed a linear recession rate close to zero (0.11 µm s–1) after two 120-s ablation cycles. It is identified that the resulting oxide scale is mainly composed of (Hf, Zr)6Ta2O17 and (Hf, Zr, Ta)O2 by performing aberration-corrected (scanning) transmission electron microscopy. The protective mechanism is related to the peritectic transformation of orthorhombic-(Hf, Zr)6Ta2O17 to tetragonal-(Hf, Zr, Ta)O2 plus Ta-dominated liquid. This study contributes to the development of Ta-containing multicomponent UHTC bulk and coatings for ultra-high temperature applications.

Microstructure and properties of multicomponent silicide ceramic coatings on Ta substrate prepared by slurry sintering method

High entropy silicide (Mo0.2Cr0.2Ta0.2Nb0.2W0.2)Si2 (named as MeSi2) coating was successfully prepared on Ta substrate by slurry sintering method. Firstly, precursor powders were initially obtained through mechanical alloying of silicide powders. Then powder slurry was coated on Ta substrate, and then the samples were sintered. For comparison, TaSi2 coating prepared by halide-activated pack cementation method was synthesized. Subsequently, the static oxidation resistance of both MeSi2 coating and TaSi2 coating was examined at 1200 °C, results revealing that the MeSi2 coating demonstrates an effective protection time of more than 60 h. The protective effect and duration of the MeSi2 coating on Ta substrate are significantly greater than that of TaSi2, indicating an improvement oxidation resistance due to the high entropy effect of the silicide coating. After oxidation, the coating evolved an outer SiO2 layer, followed by MeSi2, Me5Si3, TaSi2, and Ta5Si3 layers. As the oxidation progressed, MeSi2 gradually transformed into Me5Si3, leading to a loss of the coating's antioxidant capacity.

Microstructural development and oxidation resistance of MSi2-type multicomponent silicide coatings on Nb alloys by spark plasma sintering

MSi2-type multicomponent silicide coatings were prepared on Nb alloys by spark plasma sintering using mixed powders of Mo, Ta, W, Zr, Ti and Si. The coatings were composed of thick outer layers and thin inner layers (interdiffusion zone). A two-phase structure consisting of C11b (Mo,Ta,W,Ti)Si2 and C40 (Ti,Ta,Zr)Si2 was observed in the outer layers of all the coatings sintered for holding times ranging from 15 s to 5 min, but the distribution of these elements in each phase gradually became uniform with increasing holding time. The coatings demonstrated excellent protection during oxidation at 1300 °C for 100 h, and a continuous dense oxide scale mainly composed of ZrSiO4 and SiO2 was generated. The alternation of heating and cooling during oxidation caused cracks to appear at the interface between the outer layer and inner layer due to a mismatch of thermal expansion coefficients. However, crack extension was observed only along the inner layer toward the interior due to the multicomponent structure of the outer layer of the coating. The microstructural development and oxidation behavior of the coatings were discussed.

Exploring NiCrAlYSiTa multicomponent coatings: Combining high-throughput synthesis and CALPHAD modeling

Multicomponent alloys pose great challenges for efficiently screening desired composition. Here, we combined high-throughput magnetron-sputtering experiments and CALculation of PHAse Diagrams (CALPHAD) methods to screen NiCrAlYSiTa coatings. The compositionally graded coatings showed increased amorphization with higher Si content, indicated by the steepen T0 curves and enlarged amorphous formation region. For the crystallized coatings, the phase structure transformed from Al- and Cr-rich bcc region to Ni-rich fcc, consistent with our calculated phase diagrams. Owing to the high cohesion energy and strong atomic bonding induced by large atomic radius difference and negative mixing enthalpy, the amorphous coatings exhibited superior hardness (25.8 GPa) and elastic modulus (415.8 GPa) compared to the reported multicomponent coatings. By combining high-throughput experimental and theoretical methods, this work pioneers an integrated framework for rapid development of new multicomponent alloy coatings.

Nanocomposite coatings for wear protection at high temperatures

The investigation results of friction and wear of the developed detonation composite coatings FeAl2-Ti-Si-B under high-temperature friction conditions are presented. The choice of FeAl2-Ti-Si-B composition and its optimal content for spraying wear-resistant coatings loaded with friction under high-temperature conditions are justified. It is noted that the alloying elements at definite concentrations and technological parameters of spraying have a positive influence on the structure, properties, and quality assurance of multicomponent coatings. It is shown that the introduction of silicon and boron contributes the formation of hard-alloy high-temperature compounds with increased wear resistance. The maximum microhardness corresponds to the Cr-Si coatings with ~ 28 % titan content. In addition, the mechanical properties of the obtained material are improved by additional alloying of ~ 22 % silicon and bor. In turn, the coatings plating at a working gas flow rate in a ratio for acetylene ~ (20/25) l/min and oxygen ~ (22/27) l/min provides the chemical composition and spraying process parameters permanence as well as constant properties of coatings. The obtained results show that for the coatings of FeAl2-Ti-Si-B system at loading 5.0 MPa, sliding speed 1.5 m/s, and temperature up to 650 °C the stable performance of structural adaptability, which ensures the friction and wear parameters minimization, is demonstrated. The metallographic analysis and strip chart recording of specimens indicate that the friction surfaces are characterized by the absence of visible defects; the separate cold-welded regions are located in thin-film surface layers. The composition, structure, and tribological durability of coatings produced from the elements of the country's resource base were studied; their high adhesion, physical and mechanical characteristics and wear resistance under high-temperature conditions were defined. The thin-film surface structure patterns and properties were investigated with the help of modern physical and chemical methods of analysis. It was determined that the combination of mechanical, physical, and chemical properties of the investigated coatings provides vide opportunities for their usage as effective materials under high-temperature wear conditions. According to the test results, the application of the investigated composite coatings for friction unit efficiency improvement provides their operational reliability in accordance with requirements and opportunities that appear with the development of a new competitive material for wear-resistant coatings obtained with the help of the detonation method. Keywords: detonation coating: wear resistance, surface layer, structural adaptability, temperature.

Design and competitive growth of different spinels at 750 °C for the multi-component CuCoMnFe alloy coatings

The diversified MnCoCuFe coatings can enhance the thermal growth stability and sintering property of spinel, and the multicomponent spinel exhibits good high temperature conductivity. The oxidation products of seven composite alloy coatings at 750 °C, CoNi(Fe), CoMn(Fe), CoMnCu(Fe), MnCu(Fe), MnCuCo(Fe), CuCoMn(Fe) and CuCo(Fe) coatings, were discussed in details. Due to differences in the elements and their concentrations in the designed coatings, some coatings could produce spinel, while others did not. The designed CuCo(Fe) coating and CuCoMn(Fe) coating prepared by electrodeposition in this study with the concentration ratio approximately nCu:nCo:nMn≈1:1:1. The oxidation reaction equations for the CuCoMnFe coating and CuCoFe coating at 750 °C were discussed. CoFe2O4 spinel was preferentially formed in the CuCoFe coating and CuMn2O4 spinel was preferentially formed in the CuCoMnFe coating. Both coatings demonstrated the good high-temperature oxidation resistance and high-temperature electrical conductivity.

A review on multicomponent rare earth silicate environmental barrier coatings

Rare earth (RE) silicate environmental barrier coatings (EBCs), with superior physicochemical properties and resistance to hot water-oxygen and calcium-magnesium-aluminosilicate (CMAS) corrosion, are ideal candidates for safeguarding the next-generation aviation engines made of SiC ceramic matrix composites (CMCs). However, improving the corrosion resistance of RE silicates remains a critical challenge due to severe environmental degradation at 1500 °C. Herein, by doping multiple RE elements and designing high entropy formulations, researchers found that multicomponent RE silicates could establish stable lattice structures, phase compositions, and reaction products while impeding the infiltration of corrosive agents. This paper reviews the modulation of their phase stability, physicochemical properties, wettability, and corrosion behaviors. It looks at how state-of-the-art optimization solutions of multicomponent and high entropy doping strategies affected corrosion resistant behaviors. In conclusion, the authors suggest further studies to optimize the corrosion resistance of multicomponent RE silicates and highlight the importance of integrating multicomponent doping with high-throughput and other optimization methods, thereby unlocking an array of possibilities for advancing RE silicate EBCs.

ОБЗОР СОВРЕМЕННЫХ ДЕМПФИРУЮЩИХ СПЛАВОВ В КОНТЕКСТЕ ПЕРСПЕКТИВ АГРОПРОМЫШЛЕННОГО ПРИМЕНЕНИЯ

The article provides an information and analytical review of progressive scientific and technical solutions in the field of industrial use of modern damping alloys from the point of view of increasing the effectiveness of vibration control and industrial noise in the operation of machinery and equipment of the agro-industrial complex. In accordance with the generalized classification system for high-damping alloys, a comprehensive characteristic of alloys with an improved ability to dissipate (absorb) the energy of vibrations that occur in dynamically loaded parts (nodes) of agricultural machinery is presented. The main groups of damping alloys for effective vibration protection of elements of agroengineering systems have been identified by systematizing scientific and practical information about the key features of the most common alloys in science and industry with increased damping (dissipative) properties. It has been established that such iron-carbon alloys as alloyed steels and gray cast irons are among the most promising vibration- and noise-absorbing metal materials for the manufacture of agrotechnical facilities operating in the mode of cyclic and shock effects. The indicated iron-carbon alloys have demonstrated an increased ability to dissipate the energy of sound vibrations over a wide temperature range with an acceptable set of physico-mechanical, technological and operational parameters. It was found out that the mass use of non-ferrous metal alloys in the agro-industrial complex as vibration- and noise-absorbing metal materials is hindered by their high cost, as well as a rather limited combination of physico-mechanical (functional) properties, especially in the range of elevated temperatures. For this reason, it is recommended to pay attention to the study, development and modernization of special multicomponent damping coatings that can be applied to the main material of agrotechnical facilities using various technologies.

Erratum to: Structure and Properties of Multicomponent Diffusion Boride Coatings Formed on a Hardened 30KhGSA Steel Surface

Erratum to: Structure and Properties of Multicomponent Diffusion Boride Coatings Formed on a Hardened 30KhGSA Steel Surface

Structure and tribocorrosion properties of ultralubricated (TiAlCrSi)C multicomponent coatings prepared by FCVAD

To address corrosion and friction problems in complex environments, traditional protective coatings are gradually replaced by multicomponent coatings. In this work, a (TiAlCrSi)C multicomponent coating with ultralubrication (COF < 0.1) and excellent corrosion resistance was prepared by FCVAD technology with regulated C2H2 flow. The composition, structure, roughness, dry friction, corrosion and tribocorrosion of the (TiAlCrSi)C coating were analyzed. The results show that the (TiAlCrSi)C coating shows an amorphous structure, and the addition of carbon improves the degree of amorphization of the coating. Carbon exists in the form of carbide and amorphous carbon in the (TiAlCrSi)C coating, the carbon content saturation of the coating is about 70 at.%. The formed carbides and sp2-C in the (TiAlCrSi)C coating have extremely low COFs and good wear resistance. The high proportions of amorphous carbon and sp2-C improve the self-lubricating and nonmetallic properties of the (TiAlCrSi)C coating, which makes the coating have good tribocorrosion resistance in 5.0 wt% H2SO4 solution. The wear mode of the coating changes from abrasive wear to adhesive wear. Therefore, the (TiAlCrSi)C coating has great potential application value for tribocorrosion surface protection in a 5.0 wt% H2SO4 solution environment.

Cu/HA/ZnS/PEEK multicomponent coatings with varied copper content for biomedical applications

In this study, multicomponent Cu/HA/ZnS/PEEK coatings were electrophoretically deposited (EPD) on Zr-2.5Nb alloy substrates. The kinetics of coating deposition from suspensions with various Cu contents was studied. Heating and slow cooling enabled the densification of coatings. The densified coatings were characterized by a limited number of pores and the presence of HA agglomerates on their surface. All of the obtained coatings exhibited significant roughness and mild hydrophilicity, as well as high adhesion to the alloy substrates. The coatings increased the electrochemical corrosion resistance of the zirconium alloy. The coating obtained from the suspension with the highest copper content exhibited high antibacterial properties for both bacteria strains after 24 h. However, after 72 h incubation, the samples had a better effect against Gram-negative than Gram-positive bacteria. Furthermore, this coating variant allowed the formation of hydroxyapatite on its surface in the Kokubo test. The obtained coatings showed antibacterial and bioactive properties with potential for further development, particularly as permanent coatings for bone implant applications.

Unveiling the wear behavior of multi-component ultra-high temperature ceramic thin coatings with pulsed electro-spark deposition

The study presents a novel approach using pulsed electro-spark deposition (PED) to apply a thin protective coating of multi-component ultra-high temperature ceramics (MC-UHTCs) on a steel substrate. A single solid-solution phase of (TaNbHfTi)C-based MC-UHTC electrode is prepared using spark plasma sintering (SPS). The coating process involves melting, rapid re-solidification, and forming nano-grains (15–20 nm) resembling splash-like features. MC-UHTC coating remains stable without oxidation and any phase transformation. The bonding between the coating and the substrate is strong, regardless of the coating thickness, which can vary from <1 μm to over 25 μm. Scratch testing along the interface demonstrates that the MC-UHTC coating exhibits improved wear resistance compared to the uncoated steel substrate. This improvement is attributed to the significantly higher hardness of the coating, which is up to 4.5 times greater than substrate. The dominant wear mechanisms observed include plowing in the substrate, micro-cracking at the interface, lateral cracking and brittle fracture in the MC-UHTC coating. Overall, this study presents promising opportunities for developing innovative protective MC-UHTC coatings without needing expensive environmental chambers while preserving their chemical functionality. By employing the PED technique and utilizing MC-UHTCs, the wear resistance of structural metallic components can be enhanced effectively.