Nanostructured Composite Coatings Research Articles

Structure and properties of composite nanostructured coatings on steel

Abstract In the recent years, the development of nanotechnology has increased the applications of nanoparticles, and the possibility of incorporating them into innovative composite coatings. In this paper, we aim to improve the corrosion resistance of 42CrMo4 and 65G steels by electroless chemical deposition of Ni, reinforced by adding of nanoparticles of nanodiamants (ND), boron (B) or cubic-BN (CBN). Consequently, by this approach we extend the useful-life of these mechanical parts, making them suitable for aerospace and automotive industry.

Phase, microstructure and property evolutions of reactively synthesized YSZ-ZrC composite coating based on the content regulation of the precursor

Dense and nanostructured YSZ-ZrC composite coatings were reactively synthesized by atmospheric plasma spraying. Reactive YSZ-Al-SiC precursors with different YSZ contents were used and the evolution of the phase, microstructure and mechanical properties of the as-prepared coatings were fully revealed. Phase transformation for the YSZ component, from tetragonal phase in the start material to cubic phase in the composite coating, was validated by experimental evidences. It could be explained that the progression of in-situ reactions consumed considerable volume of zirconia and then led to higher Y/Zr ratio of Y-Zr-O melt in the droplets and then cubic phase was retained. Based on the content regulation of the reactive components, the highest yielding of ZrC phase was 35.4 wt% and the highest microhardness and fracture toughness of the composite coatings were 823 HV0.1 and 2.79 MPa/m2.

Tribotechnical characteristics of nanostructured multilayer composite coatings on tools for machining heat-resistant alloys

The paper presents the results of theoretical and experimental research of tribotechnical characteristics (tool wear on the back surface, tool durability period, critical cutting path length before blunting) of innovative nanostructured multilayer composite coatings on the tool for milling heat-resistant alloys of aerospace parts.

Study of Tribotechnical Properties of Multilayer Nanostructured Coatings and Contact Processes during Milling of Titanium Alloys

The paper presents the results of theoretical and experimental research on tribotechnical characteristics: tool wear on the back surface, tool durability period, critical length of the cutting path before blunting, adhesion component of the friction coefficient, contact processes, temperature, and force dependences for the application of innovative nanostructured multilayer composite coatings on a tool for milling of titanium alloys. The proposed thermodynamic model of cutting tool wear allows us to determine the ways by which cutting tool wear intensity decreases and the conditions of increase in cutting tool wear resistance with wear-resistant coatings. A substantial increase in wear resistance of end mills when processing titanium alloys with the use of innovative multilayer nanostructured coatings is established, in particular an improvement of an average of 1.5–2 times. These positive results are related to a significant decrease in temperature–force loading in the cutting zone, a decrease in the friction coefficient (adhesion component), and the phenomenon of adaptation (self-organization) of friction surfaces during cutting by tools with wear-resistant coatings, contributing to the formation of films of various compounds with shielding, protective, and lubricating properties.

Wear resistance of innovative multilayer composite coatings on tool during milling of heat-resistant alloys

The paper presents the results of theoretical and experimental research of tribotechnical characteristics (tool wear on the back surface, tool durability period, critical cutting path length before blunting) of innovative nanostructured multilayer composite coatings on the tool for milling heat-resistant alloys of aerospace parts.

Development of a technology for magnetron sputtering of composite nanostructured coatings from an alloy of the V–Ti–Cr–TiC system

The results of the study of alloys of the V–Ti–Cr–TiC system for obtaining composite nanostructured coatings using the magnetron sputtering are presented. The studied coating has a high level of microhardness and wear resistance.

A Comparison Study of the Friction and Wear Behavior of Nanostructured Al2O3-YSZ Composite Coatings With and Without Nano-MoS2

A Comparison Study of the Friction and Wear Behavior of Nanostructured Al2O3-YSZ Composite Coatings With and Without Nano-MoS2

MAPLE Coatings Embedded with Essential Oil-Conjugated Magnetite for Anti-Biofilm Applications.

The present study reports on the development and evaluation of nanostructured composite coatings of polylactic acid (PLA) embedded with iron oxide nanoparticles (Fe3O4) modified with Eucalyptus (Eucalyptus globulus) essential oil. The co-precipitation method was employed to synthesize the magnetite particles conjugated with Eucalyptus natural antibiotic (Fe3O4@EG), while their composition and microstructure were investigated using grazing incidence X-ray diffraction (GIXRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), transmission electron microscopy (TEM) and dynamic light scattering (DLS). The matrix-assisted pulsed laser evaporation (MAPLE) technique was further employed to obtain PLA/Fe3O4@EG thin films. Optimal experimental conditions for laser processing were established by complementary infrared microscopy (IRM) and scanning electron microscopy (SEM) investigations. The in vitro biocompatibility with eukaryote cells was proven using mesenchymal stem cells, while the anti-biofilm efficiency of composite PLA/Fe3O4@EG coatings was assessed against Gram-negative and Gram-positive pathogens.

Study of the composition and properties of vacuum coatings based on titanium carbide

Carbide cutting tools are used for machining of machine parts made of complex alloyed materials. Application of protective composite nanostructured coatings on carbide cutting tools allows increasing the service life of cutting tools several times. The coating on their base protects the cobalt binding of carbide alloys. The low thermal conductivity of the composite nanostructured titanium carbide coating means that the heat generated when cutting workpieces is mostly transferred to the chips so that the tool does not become overheated. This is important when machining difficult alloyed, hard-to-machine, ductile materials for which the temperature at the contact zone of the cutting edge and the machined material reaches up to 900°C. The adhesive interaction of the composite nanostructured coating with the substrate material is of no small importance in selecting the coating composition. From this point of view, carbide titanium coatings have good compatibility with carbide cutting tools. Along with this, the study of ion-plasma composite nanostructured coatings based on TiC carbides is relevant. The study results of the composition and properties of vacuum composite nanostructured coatings based on titanium carbides obtained by the ion-plasma method are presented. Studies of the chemical composition, the electronic and atomic structure of composite nanostructured coatings based on Ti carbides were carried out using the HREELS, XPS, and AES method and based on experimental studies of composite nanostructured TiC coatings, the p – T – x diagrams for TiC were refined.

Physical Alloying of Plasma Metallization Carbide Nanocomposite Coating by Allotropic Carbon Nanostructures

The fundamental scientific problem for micro- and nano-electronics has been solved—methods for creating and investigating properties of physically doped materials with spatially inhomogeneous structure at the micro- and nano-meter scale have been developed. For the application of functional nanocomposite film coatings based on carbides of various transition metals structured by nanocarbon, for the first time in the world, we developed a new technique for their plasma deposition on a substrate without the use of reaction gases (hydrocarbons such as propane, acetylene, etc.). We have created nanostructured film materials, including those with increased strength and wear resistance, heterogeneous at the nanoscale, physically doped with nanostructures—quantum traps for free electrons. We learned how to simultaneously spray (in a plasma of a stationary magnetron discharge) carbides and graphite from a special mosaic target (carbide + carbon) made mechanically. As a result of such stationary sputtering of carbides and carbon, plasma nanostructured coatings were obtained from nanocarbides, metal nanocrystals and nanocarbon. Our design of such a target made it possible to intensively cool it in the magnetron body and spray its parts (carbide + carbon) simultaneously with a high power density of a constant plasma discharge—in the range of values from 40 W/cm2 to 125 W/cm2. Such sputtering with a change in the power or the initial relative surface areas of various parts of the mosaic target (carbon and carbide) made it possible to change the average density of carbide, metal and carbon in a nanostructured (nanocarbon and metal nanostructures) coating. The changed relative density of various components of the nanocomposite (nanostructures of carbide, metal, and carbon in the form of graphite) significantly affected the physical properties of the nanocomposite coating. The creating method of multiphase nanostructured composite coatings (based on carbides of transition metals) with high hardness of 30 GPa, a low coefficient of friction to dry 0.13 - 0.16, with high heat resistance up to 3000&#176C and thermal stability in the nanocrystalline state over 1200&#176C is developed. It is established that the presence of nanographite in the composite significantly improves the impact strength and extends the range of possible applications, compared with pure carbides. The solution to this problem will allow creating new nanostructured materials, investigating their various physical parameters with high accuracy, designing, manufacturing and operating devices with new technical and functional capabilities, including for the nuclear industry and rocket science.

Ag Functionalization of Al-Doped ZnO Nanostructured Coatings on PLA Substrate for Antibacterial Applications

Developing smart, environmentally friendly, and effective antibacterial surfaces is fundamental to contrast the diffusion of human infections and diseases for applications in the biomedical and food packaging sectors. To this purpose, here we combine aluminum-doped zinc oxide (AZO) and Ag to grow nanostructured composite coatings on bioplastic polylactide (PLA) substrates. The AZO layers are grown by RF magnetron sputtering, and then functionalized with Ag in atomic form by RF magnetron sputtering and in form of nanoparticles by supersonic cluster beam deposition. We compare the morphology, wettability, and antimicrobial performance of the nanostructured coatings obtained by the two methods. The different growth modes in the two techniques used for Ag functionalization are found to produce some differences in the surface morphology, which, however, do not induce significant differences in the wettability and antimicrobial response of the coatings. The antibacterial activity is investigated against Escherichia coli and Staphylococcus aureus as representatives of Gram-negative and Gram-positive bacteria, respectively. A preferential antimicrobial action of Ag on the first species and of AZO on the second one is evidenced. Through their combination, we obtain a hybrid composite coating taking advantage of the synergistic dual action of the two materials deposited, with a total bacterial suppression within few minutes for the first species and few hours for the second one, thus representing a valuable solution as a wide-spectrum bactericidal device.

Nanocomposite coating with high microhardness based on the agglomerated Kh20N80-WC powder system

This article explores the characteristic and particular features of manufacturing nanostructured composite coatings with high microhardness from agglomerated powders of Kh20N80-WC system manufactured by high-speed mechanosynthesis. The properties of the functional coatings deposited by both supersonic cold gas-dynamic and microplasma spraying are studied.

Effect of Cl– and $${\text{NO}}_{3}^{ - }$$ Ions on Microstructure and Properties of TiO2–CeO2 Nanostructured Composite Coatings Obtained Through Plasma Electrolytic Oxidation (PEO) on Ti6Al4V

Rare earth cerium oxide synthesized from cerium (III) chloride and cerium (III) nitrate salts in electrolytes were used to develop nanostructured composite coatings by plasma electrolytic oxidation (PEO) technique on Ti6Al4V. The micro-hardness (542 HV) and corrosion resistance of fabricated coat in the electrolyte containing cerium (III) nitrate was notable. Formation of the ceria/titania nanostructured composite originated from the nitrate salt during PEO process acted as a barrier to the porosity growth and exhibited a higher impedance resistance (8.6 × 105 Ω Cm2) at the lower frequency and higher corrosion resistance (2.26 × 10–3 mm y–1) in 0.1 M HCl solution at the room temperature than the fabricated coat in PEO-electrolyte containing the cerium (III) chloride salt. Structural characterization techniques such as (X-ray diffraction) XRD, (scanning electron microscope) SEM and (energy disperse spectroscopy) EDS were used to investigate the microstructure and morphology of the coatings. Fourier transform infrared spectroscopy (FT-IR) was utilized to recognize and to confirm the development of bonds with wavelength of 457 and 530 cm–1 corresponded to the stretching vibration (Ce–O) of the attracted cerium oxide nanoparticles in the coatings. The result demonstrated that CeO2 nanoparticles were created and drawn into the discharge channels of sample CS3 during the PEO has led to the enhancing of the composite coating thickness (31 µm) and corrosion resistance, too.

A plasma-chemical reactor of coupled vacuum-arc and ion-plasma processes for protective coatings formation based on titanium nitride

A plasma-chemical reactor based on the principle of coupling of gas-discharge processes in a VU-1B vacuum installation has been developed. This plasma-chemical reactor combine vacuum-arc evaporation of titanium in a nitrogen-containing plasma and ion-plasma sputtering of copper with the formation of copper vapor. The basis of this method of coatings deposition is the principle of dosing the injection copper vapor into the region of TiN synthesis through a separating diaphragm with a variable metering aperture, which prevents penetration of a titanium vapor into the copper cathode of the magnetron. The synthesis of TiN coatings in copper vapors has been carried out with the formation of nanostructured composite TiN-Cu coatings.

Corrosion behavior of Ni/WC nano-structured composite layers synthesized by electrochemical method

Ni/WC nano-structured composite coatings were developed by electrodeposition method from a nickel plating electrolyte containing WC nanoparticles (diameter size of ~60 nm). The corrosion behavior of Ni/WC nano-structured composite coatings and pure Ni coating were comparatively investigated in wet conditions in the solution that simulates the primary water of Pressurized Water Reactors (PWRs). The morphology and chemical composition of the obtained coatings before was observed through scanning electron microscopy (SEM) connected to an energy dispersive X-ray system (EDX). The open circuit potential (OCP) and Electrochemical Impedance Spectroscopy (EIS) methods were used to evaluate the corrosion behavior, at room temperature. The nanohardness of pure Ni and Ni/WC nanocomposite coatings was tested by nanoindentation technique. SEM-EDX analyze proved that WC nanoparticles were successfully incorporated into Ni matrix. Presence of WC nanoparticles in the nickel matrix transforms surface morphology from regular pyramidal to irregular global and changes the crystallizations of nickel matrix to smaller and thinner crystallites. Ni/WC nanocomposite coating revealed a higher nanohardness value in comparison with pure Ni coating. The corrosion resistance of Ni/WC nanocomposite coating is higher under similar experimental conditions as compared with pure nickel layers, proving an enhancement of corrosion resistance.

Effect of current density, MoS2 content and bath agitation on tribological properties of electrodeposited nanostructured Ni-MoS2 composite coatings

ABSTRACTNanostructured nickel coatings with molybdenum disulphide particles were electrodeposited to form composite coatings. Three different current densities, i.e. 3, 5 and 7 A/dm2 were investigated initially. The best results were obtained with 5 A/dm2 for codeposition of nanostructured Ni-MoS2 composite coatings. With the addition of 1–4 g/L molybdenum disulphide to the bath, the weight percentages of MoS2 particles in the coatings were 23–38%. This increase of MoS2 content was accompanied with decrease in friction coefficient of the coatings from 0.35 to 0.08. Wear resistance of the coatings was increased with increasing MoS2 content and the weight loss was decreased from 1.4 to 0.7 mg. Hardness was decreased from 585 to 400 VHN with increasing the MoS2 content. By increasing bath agitation speed up to 150 rpm, more MoS2 particles were embedded in the matrix and the coatings showed better wear resistance. However, increase of agitation speed from 150 to 200 rpm caused a decrease of MoS2 particles in the nickel matrix due to the turbulent motion of particles in the bath. Overall, it was shown that the lubricating effect of MoS2 in the coating was more influential than the nanocrystallinity of the nickel matrix in improving tribological properties of these composite coatings.

On the prospects of application of nanostructured heterophase polyfunctional composite materials inengine building industry

The paper gives a brief review of properties and applications of developed extra-hard nanostructured composite materials and coatings based on them. The presentresearch suggestsaerospace applications of nanostructured composite materials based on carbides, carbonitrides and diboridesof transition and refractory metals. To improve the technical and economic performance of gas turbine engines, it is advisable to use new composite structural materials whose basic physicomechanical properties are several times superior to traditional ones. The greatest progress in developing new composites should be expected in the area of materials created on the basis of polymer, metal, intermetallic and ceramic matrices. Currently components and assemblies of gas turbine engines and multiple lighting power units with long operation life and durability will vigorously develop. Next-generation composites are studied in all developed countries, primarily in the United States and Japan.

Influence of Thickness of Multilayer Composite Nano-structured Coatings on Tool Life of Metal-Cutting Tool

The paper is focused on turning of structural steels C45. Cutting tools were represented by carbide cutting inserts without coatings, with reference coating TiAlN, as well as with multilayered composite nano-structured coatings Ti-TiN-(TiCrAl)N and Zr-ZrN-(ZrCrNbAl)N (of different thickness of 3-7 μm). The following studies of the properties of coated tools were carried out: measurement of microhardness and strength of adhesion bonds in the “tool-coating” system and investigation of elemental and phase compositions of coatings. The cutting tests were carried out at the following cutting modes: f = 0.2 mm/rev; аp = 1.0 mm; vc = 200, 250, 300, 350 and 400 m/min.

Investigation of wear dynamics for cutting tools with multilayer composite nanostructured coatings in turning constructional steel

The paper deals with the wear dynamics shown by carbide tools with multilayer composite nanostructured coatings of various compositions. The investigation involved coatings based on nitrides of such metals as Ti, Zr, Cr, Nb, and Al with three-layer architecture, including adhesion, transition, and wear-resistant layers. The thickness of the coatings was about 4 µm. There was a series of cutting tests involving tools with the coatings under study in the turning of AISI 1045 steel at vc = 200, 250, 300, and 350 m/min. The comparative studies were conducted to investigate wear process patterns for tools with the coatings under study and for uncoated tools and tools with TiN reference coatings, depending on the cutting speed. In particular, the study considered the intensity and specific features of crater formation on the tool rake face. In particular, it was found that an increase in cutting speed led to more active movement of a crater away from the cutting edge, while at lower cutting speeds, a crater developed evenly. Diffusion and oxidation processes were registered and studied at the boundary between the coating and the material being machined. The use of the coatings under study makes it possible to significantly increase the cutting speed, while the optimal composition of the coating depends on the applied cutting speed.

Characterization and in vitro bioactivity of electrophoretically deposited Mn-modified bioglass-alginate nanostructured composite coatings

Manganese is an essential element for the natural growth of bones, contributing to increased mineral density in bones and also effective in preventing osteoporosis. In present study, Mn-modified 45S5 bioglass nanopowder with 0, 1 and 1.5 wt% MnO was synthesized by sol-gel method. Then, Mn-modified bioglass/alginate nanostructured composite coatings were deposited on stainless steel 316L by electrophoretic deposition process and characterized by means of x-ray diffraction, Fourier-transform infrared spectroscopy, and field-emission scanning electron microscopy equipped with an energy dispersive x-ray spectroscopy. In vitro bioactivity test in simulated body fluid solution showed that the ionic exchange in the presence of manganese was well done and addition of manganese to bioglass improved the bioactivity of composite coating. It was also confirmed by electrochemical impedance spectroscopy analysis that the increase of manganese in bioglass had a positive effect on the corrosion resistance of coatings after immersion in simulated body fluid solution.