Search Results (1,384)

The design and main parameters of a plasma–chemical reactor containing two compartments are presented. One compartment houses a vacuum-arc evaporator, while the other houses a planar magnetron. The compartments are separated by a diaphragm with a dosing slot for injecting copper vapor into the TiN synthesis compartment. The conditions for the synthesis of superhard TiN-Cu composite coatings are experimentally determined. Based on established process parameters for TiN synthesis in a nitrogen-containing plasma by Ti evaporation using a vacuum-arc discharge, it is proposed to apply TiN-Cu coatings by injecting Cu vapor into the TiN synthesis area and sputtering Cu using a magnetron discharge. XRD analyses of both TiN and TiN-Cu coatings show the presence of WC, Ti₂C, and TiN. EDS analysis confirms 5.57 at. % copper on the surface of the TiN-Cu coating. Real-life operating tests of TiN-Cu coatings on replaceable WC-TiC-Co (79/15/6 wt.%) alloy hexagonal inserts used for cutting 40Kh steel revealed that applying the TiN-Cu coating extends the tool life of WC-TiC-Co inserts by about 2.5 times compared with uncoated tools. Cutting force measurements on TiN-Cu-coated inserts showed no vibration or noise during cutting, driven by a reduced friction coefficient and improved heat dissipation at the contact zone between the cutting edge and the workpiece, thereby lowering the temperature in that area. Full article

TiN/CrAlN multilayer coatings were synthesized by cathodic arc deposition using 2-fold substrate rotation and alternating targets. The effect of substrate rotation on the layer sequence, elemental fluctuations and interface quality was examined using high-resolution transmission electron microscopy and atom probe tomography. The layers exhibited semi-coherent growth across the interfaces. Minor interface roughness and elemental intermixing limited to below 2 nm at the interface could be observed. Further, the formation of a Ti-enriched sublayer in the Cr_1−xAl_xN as a result of the 2-fold rotation was identified. Full article

In the realm of computational biomechanics, quantifying the reliability of surface-engineered implants is critical yet challenging due to material anisotropy and experimental limitations. Standard deterministic approaches often fail to capture the failure probability of brittle coatings, compromising the accuracy of lifespan predictions. This study’s originality lies in a stochastic framework that addresses titanium boride data scarcity using a geometric decision node (GDN). By autonomously switching between Palmqvist and Radial-Median regimes, the GDN eliminates deterministic bias and provides a failure-probability-based reliability assessment, thereby surpassing the limitations of conventional models. The evaluation was carried out on powder-pack borided Ti6Al4V layers produced at 1000 °C (10, 15, and 20 h). By combining instrumented Berkovich nanoindentation (N = 14, hardness scatter 17.6–34.8 GPa) with a Monte Carlo simulation algorithm (n = 10,000), we successfully modeled the stochastic brittle failure of the coating. The computational model, governed by a multivariate joint probability density function (JPDF), revealed a mixed-mode fracture mechanism where 77.9% of the virtual population developed radial cracks while 22.1% re mained in the Palmqvist regime. Weibull statistical analysis yielded a characteristic toughness of 2.25 MPa·m^1/2 and a low modulus of m = 1.58. This low modulus mathematically quantifies the coating’s sensitivity to microstructural defects, demonstrating that probabilistic algorithms—rather than mean-value deterministic calculations—are essential for ensuring the structural integrity of borided components in biomechanical design applications. Full article

Cr₂O₃-based ceramic coatings are widely used in wear-critical applications; however, their tribological performance under dry sliding conditions can be limited by brittleness and frictional instability. In heavy-duty vehicles, the king pin–bushing contact operates under severe dry sliding conditions, motivating the investigation of composite Cr₂O₃–nTiO₂ coatings as a potential surface engineering solution. In this study, Cr₂O₃–TiO₂ coatings containing 0, 10, 20, 30, and 40 wt% TiO₂ were deposited by atmospheric plasma spraying (APS) from mechanically mixed powders. Phase composition was analyzed by X-ray diffraction using an X’Pert PRO MRD diffractometer, while microstructure and elemental distribution were examined by scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS) on a FEG Quattro C microscope. Mechanical properties were evaluated by Vickers microhardness, instrumented indentation and scratch testing, while dry sliding wear behavior was assessed by pin-on-disc tests performed on a CETR UMT-2 tribometer against a bronze counterbody, with continuous monitoring of the coefficient of friction (COF). The results show that plasma spraying produces lamellar composite coatings with intrinsic porosity and locally modified phase composition. Cr₂O₃-rich coatings exhibit higher hardness (1198 HV2 compared with 877 HV2 for Cr₂O₃–40TiO₂ corresponding to an increase of approximately 36%) and improved resistance to indentation, reflected by lower penetration depths and higher elastic modulus values (134 GPa for S0 compared with 77 GPa for S2). These coatings also exhibit a more stable friction response and reduced material transfer from the bronze counterbody, as confirmed by the lower mass loss of the pins (0.0295 g for S0 compared with 0.0473 g for S4, corresponding to a reduction of about 38%). Increasing TiO₂ content leads to changes in friction stability and wear behavior associated with microstructural heterogeneity. These findings indicate that the sliding wear performance of Cr₂O₃–nTiO₂ coatings is governed by elastic–plastic stability under localized contact loading and support their applicability for dry sliding king pin–bushing systems in heavy-duty vehicles. Full article

Conducting polymer–metal nanocomposites are widely investigated as tunable photonic and optoelectronic media; however, reported property trends often remain empirical because electronic disorder at the absorption edge, refractive-index dispersion, free carrier dielectric response, and third-order nonlinearity are rarely quantified within a single, composition-controlled film series. This limitation is particularly relevant for electrochemically grown PANI coatings on transparent conductive substrates, where nanoparticle incorporation can simultaneously enhance polarization while introducing aggregation-driven heterogeneity. Here, Ag/PANI nanocomposite thin films were fabricated directly on indium tin oxide (ITO) by potentiostatic electrodeposition from an aniline/camphorsulfonic acid electrolyte containing controlled Ag nanoparticle loadings (5–15 wt.%). This study addresses the research gap by integrating complementary optical-disorder and dispersion formalisms with dielectric and nonlinear analyses to establish a composition structure optics map for device-relevant films. Ag incorporation narrows the indirect optical gap from 1.98 eV (PANI) to 1.81 eV (5 wt.%), 1.38 eV (10 wt.%), and 1.19 eV (15 wt.%), while markedly broadening the Urbach tail (0.377 eV → 1.28–1.64 eV at 5–10 wt.%). Wemple–DiDomenico modeling and Drude-type dielectric dispersion reveal strongly non-monotonic evolution of oscillator energetics and the carrier response, culminating in large bound-electron dielectric constants (ε_∞ up to 469.8) and plasma frequencies (ω_p up to 248 × 10¹² Hz) at 15 wt.% Ag. Third-order nonlinearity is substantially enhanced but composition-sensitive: χ³ increases from 6.73 × 10⁻⁹ esu (PANI) to ~7.6 × 10⁻⁸ esu at 5 and 15 wt.%, whereas the Kerr coefficient peaks at 25.91 × 10⁻⁷ esu for 5 wt.% and is suppressed at intermediate/high loading. These results demonstrate that the optimal nonlinear performance is governed by a disorder–dispersion balance and microstructure-dependent local-field effects rather than the Ag fraction alone. Full article

This study aimed to investigate the tribological properties and lubrication mechanisms of three cycloalkane carboxylic acids (cyclopropane, cyclobutane, and cyclopentane) as additives in PAO4 base oil. The testing was conducted in a TiN/steel tribosystem under ball-on-flat reciprocating sliding motion with a maximum contact pressure of 0.9 GPa. Notably, cyclopropane carboxylic acid exhibited excellent anti-friction and anti-wear properties, achieving a microscale coefficient of friction of 0.008 and a wear rate of only 7.0 × 10⁻⁸ mm³/N·m. XPS and Raman analyses of the tribofilms revealed that all three cycloalkane carboxylic acids underwent tribochemical reactions during frictional motion to form carbon-based tribofilms with varying contents. Moreover, cyclopropane carboxylic acid exhibited significant tribochemical reactions, forming carbon-based tribofilm with superior tribological properties. This behavior can be attributed to the stability and size of the carbon ring in cycloalkane, which influences its dissociation and the formation of carbon-based tribofilm under high-temperature and contact stress conditions. Full article

This work focuses on the study of tribo-mechanical and microstructural properties of TiCN/ZrCN multilayer coatings with a modulation period of 12 nm, obtained by a conventional cathodic arc technique. The coatings were deposited at a temperature of 320 °C using nitrogen and methane reactive gases (N₂/CH₄) mixture in three different proportions. Surface morphology, composition, hardness, adhesion, friction and wear behavior were studied using atomic force microscopy, scanning electron microscopy with energy dispersive spectroscopy, X-ray diffraction, Raman spectroscopy, nanoindentation, and scratch and wear tests. The analysis of the coating composition revealed a strict dependence of the carbon content on the CH₄ flow rate. It was found that the coatings with a carbon content of 14.6 at.% and 15.9 at.% consist of crystalline TiZr (C,N) with the presence of amorphous carbon. All the studied TiCN/ZrCN coatings showed improved tribo-mechanical properties compared to TiN/ZrN multilayers obtained under the same deposition conditions. The highest hardness of 40 GPa was obtained for the coating deposited at a N₂/CH₄ flow rate of 370/100 sccm. The lowest wear rate of 3.16 × 10⁻⁶ mm³/N·m under dry sliding conditions was observed in the multilayer coatings deposited at the N₂/CH₄ flow rates of 330/140 sccm. Full article

Chemical vapor deposited (CVD) TiN and TiB₂ are both commonly used as wear-resistant hard coatings. The two materials exhibit pronounced differences in their properties, which can be exploited by combining them in a multilayer architecture. Thus, two multilayer coatings with different bilayer periodicities of ~80 and ~220 nm were synthesized. The multilayer architecture constrains the TiN grain size to dimensions comparable to the individual sublayer thickness, which are substantially smaller than those observed in the single-layer TiN reference coating. This grain refinement leads to significantly higher hardness of the TiN sublayers within the multilayer system compared to the single-layer coating. In contrast, the low grain size of the TiB₂ coating appears unaffected, and the hardness of the TiB₂ layers in the multilayer and corresponding bilayer reference coating is also comparable. The compressive residual stress in the TiB₂ layers decreases with decreasing layer thickness, while the tensile residual stress in the TiN layers increases, resulting in a roughly constant stress difference between the sublayers, which is also comparable to the conventional TiN/TiB₂ bilayer reference coating. However, while the tensile stress in the TiN sublayers is constant over coating thickness, TiB₂ exhibits a pronounced gradient with only low compressive stress at the interface to the substrate, which increases significantly with increasing coating thickness. The fracture properties of the multilayers range between the values obtained for the corresponding reference coatings. Complementary finite element method simulations revealed that, for the multilayer coatings, the common assumption of a stress-free state of micro-cantilevers used for bending tests is not valid. Full article

In this work, for the first time, we applied and determined the mechanical characteristics of protective coatings made of high-entropy alloy (TiZrVCrAl)N with different architectures onto the surface of Ti-6Al-4V alloy with the initial coarse-grained and ultrafine-grained structure using arc physical vapor deposition. We designed and prepared three coating architectures: a monolayer nitride coating (TiZrVCrAl)N, a multilayer coating consisting of nine alternating layers of TiZrVCrAl and (TiZrVCrAl)N, and a multilayer coating consisting of 720 alternating layers of (TiZrVCrAl)N and TiN, with a total thickness not exceeding 2 microns. We evaluated their protective performances by nanoindentation and scratch tests. Importantly, the effect of the substrate microstructure on the coatings’ performance is investigated by comparing their mechanical behavior on coarse-grained and ultrafine-grained Ti-6Al-4V. Our experimental results show that the coating performance improves with increasing number of layers in the coating, and this effect is even more pronounced for the multilayer coating deposited on the ultrafine-grained titanium alloy substrate. We also find that the (TiZrVCrAl)N/TiN (720 layers) multilayer coating deposited on the UFG Ti-6Al-4V alloy substrate exhibits the highest H/E- and H³/E²-values, indicating the coating’s high innovative potential for performance in extreme conditions. The origins of this phenomenon are analyzed and discussed. Full article

Laser powder bed fusion has attracted increasing attention for the production of metallic substrates intended for surface functionalization by advanced physical vapor deposition coatings. This study investigates the influence of the substrate manufacturing route on the performance of titanium–aluminum–silicon nitride-coated AISI 316L stainless steel, with particular emphasis on substrates produced by laser powder bed fusion. Conventionally manufactured and additively manufactured AISI 316L substrates were coated with a titanium–aluminum–silicon nitride layer using high-power impulse magnetron sputtering. The substrates were characterized by tensile testing and microhardness measurements, while coating thickness and uniformity were evaluated using the crater ball method. The mechanical integrity of the coating–substrate system was assessed by progressive load scratch testing. The additively manufactured substrate exhibited a significantly higher yield strength (411 MPa) compared to the conventionally manufactured material (257 MPa), together with increased microhardness. The titanium–aluminum–silicon nitride coating showed a uniform thickness of 4.47 µm and a well-defined coating–substrate interface. Scratch tests revealed a delayed onset of coating damage on additively manufactured substrates, with the transition to severe adhesive failure occurring at higher normal loads compared to the conventionally manufactured substrate. These results demonstrate that AISI 316L stainless steel produced by laser powder bed fusion provides a mechanically robust substrate for titanium–aluminum–silicon nitride coatings deposited by high-power impulse magnetron sputtering, with favorable coating response under progressive loading conditions. Full article

Metal packaging materials remain fundamental across food, beverage, pharmaceutical, cosmetic, and technical sectors owing to their combination of mechanical robustness, total light and gas barrier performance, thermal resistance, and established recyclability. Aluminum alloys, tinplate, tin-free steel (TFS/ECCS), stainless steels, metal–matrix composites (MMCs), and metal–polymer or metal–paper laminates define distinct metal-based packaging architectures whose metallurgical and interfacial design governs forming behaviour, corrosion and migration pathways, coating integrity, and mechanical reliability. In this review, these architectures are examined from a materials- and systems-oriented perspective, linking composition, microstructure, processing routes, and surface engineering to functional performance across rigid, semi-rigid, and flexible formats. The analysis also considers the ongoing transition from bisphenol A (BPA)-based epoxy linings to BPA-free and hybrid coating chemistries, the use of nano-structured metallic and metal-oxide surfaces, and the role of composite laminates in which thin metallic foils are combined with polymeric or paper-based structural layers. These material and architectural aspects are discussed together with safety, regulatory, and circularity considerations that increasingly influence the design and selection of metal-based packaging. Ion migration, coating degradation, and corrosion under realistic storage environments are considered in relation to EU, FDA, ISO, and sector-specific requirements, while attention is also paid to the contrast between well-established closed-loop recycling infrastructures for aluminum and steel and the more complex end-of-life management of coated metals and multilayer laminates. The review provides a unified framework connecting materials selection, metallurgical design, processing, performance, regulatory compliance, and sustainability in metal-based packaging systems. Applications spanning consumer goods, pharmaceuticals, cosmetics, and advanced electronics are integrated to support an overall understanding of how metallic and hybrid metal-based architectures underpin functional reliability and life-cycle sustainability. Full article

This work focuses on obtaining a titanium nitride coating on the surfaces of titanium and its alloy powders using a novel method, self-shearing reactive milling, under a nitrogen pressure of 50 bar. The Ti, Ti6Al4V, and Ti-5553 spherical powders were milled for up to 10 h at ambient temperature without grinding balls. As a result of the experiments, a thin, brittle TiN coating formed on the powders’ surfaces. The cross-sections of the milled powders reveal that the TiN layer thickness is in the nanometer range (about 500 nm). By analyzing the sequence of X-ray diffraction patterns, it is evident that only for the Ti6Al4V powder milled for 10 h, two peaks are observed that can be attributed to a TiN phase. On the other hand, Raman spectroscopy revealed characteristic TiN spectra even for samples collected at the initial stage of self-shearing reactive milling. An important aspect of the experiment was the preservation of the spherical shape of the milled powders, which makes them a potential feedstock for additive manufacturing of functionally graded biomaterials. Full article

Three types of gradient plasma-assisted chemical vapour deposition (PACVD) coatings were produced on WC-Co hardmetal substrates: a TiN coating, a gradient TiCN coating with alternating TiN/TiCN layers and a multilayer TiBN system of TiN/TiB₂ layers. Their corrosion behaviour in a chloride environment was compared using direct current and alternating current electrochemical techniques. Potentiodynamic polarization, linear polarization and electrochemical impedance spectroscopy were carried out in 3.5 wt.% NaCl at temperature 20 ± 2 °C in a three-electrode cell with a saturated calomel electrode (SCE) reference. After 1000 s open circuit stabilization, TiN coating showed superior corrosion resistance with E_corr = 15 mV vs. SCE, versus TiCN (E_corr = −281 mV) and TiBN (E_corr = −304 mV). Linear polarization resistance/Tafel analysis showed significantly higher polarization resistance of TiN (R_p = 1559 kΩ∙cm²) than TiCN (195.4 kΩ∙cm²) and TiBN (243.6 kΩ∙cm²), with the lowest corrosion current density, j_corr = 10.97 nA∙cm⁻² and corrosion rate v_corr = 117.2 × 10⁻⁶ mm∙y⁻¹. TiCN showed the highest j_corr (360.8 nA∙cm⁻²) and v_corr (3.32 × 10⁻³ mm∙y⁻¹). Electrochemical impedance spectroscopy fitting with a R(QR) circuit confirmed this, with the highest charge transfer resistance at the substrate–electrolyte interface (R_ct) for TiN (8.198 × 10⁴ Ω∙cm²), lower for TiBN (7.929 × 10⁴ Ω∙cm²) and lowest for TiCN (1.435 × 10⁴ Ω∙cm²), indicating TiN as the best barrier and TiCN as the most permeable. Full article

Aiming at the problem of non-uniform and non-universal evaluation criteria of machine tools’ carbon emissions in the whole life-cycle analysis, an evaluation method of life-cycle carbon-emission analysis of machine tool based on declared unit was put forward by analyzing and summarizing the existing carbon emission evaluation models. A universal evaluation system for machine-tool life-cycle carbon-emission analysis was first established, and an appropriate declared unit was then selected according to industry characteristics and machine-tool types. Subsequently, an information-flow-based iERWC boundary division method was proposed to support data collection and carbon-emission calculation across five life-cycle stages. To better reflect carbon emissions in the phase of application, the life-cycle inventory incorporates the use of coated cutters, including the associated cutters’ consumption and replacement demands. Two heavy duty floor-milling and boring machine tools produced by Qiqihar No. 2 Machine Tool (Group) Co., Ltd. Were taken as examples to calculate and evaluate life-cycle carbon-emission analysis of machine tools, and the uncertainty analysis was carried out; the possible influencing factors were pointed out to ensure the comprehensive carbon-emission assessment of the whole life cycle. Full article

Biofouling, the formation of a biofilm on submerged surfaces, is a widespread problem affecting all of the maritime industries and ecosystems. Historically, antifouling solutions have included toxic compounds, such as heavy metals and tributyl tin. Recently, less-toxic antifouling paints have been explored, including paints made from antioxidant-rich plants, and a study measured the effectiveness of polymer blends containing Aronia mitschurinii extracts. This new study will compare those results with polymer blends made from extracts of juvenile ginger and holy basil, two plants rich in antioxidants and essential oils. Extracts were assessed for antioxidant and essential oil content. Then, slides coated with a polymer-extract blend were exposed to freshwater and saltwater for three weeks and assessed by contrast microscopy. For freshwater and saltwater analysis, holy basil extracts had a minimum precipitation count of 3.40 ± 0.4 and 22.4 ± 6.0 for non-stained slides and 58.3 ± 7.3 and 9.3 ± 1.0 for stained. Ginger extracts had a minimum precipitation count of 3.9 ± 0.8 and 87.1 ± 17.3 for non-stained slides, and 5.4 ± 1.8 and 9.5 ± 0.3 for stained slides. All minimum precipitation counts for ginger and holy basil were less than those measured by controls and Aronia mitschurinii, showcasing the antifouling potential of ginger and holy basil extracts at a compatible but slightly lower level, but one that is much higher than was reported for other plant materials. Full article