Wear Resistance Of Coatings Research Articles

Development and properties of new powder materials

Problem. The study analyzed powder materials to obtain wear-resistant coatings. Field tests for wear resistance were conducted using the method of friction between two surfaces. The tests were carried out on the universal test bench SMC-2 at a rotation speed of 200 rpm. A pressure of 100 kgf was applied to the test sample. Goal. The wear resistance test cycle comprised 200,000 revolutions, with lubrication provided through the drop method. Special powders were used in the experiment, including PG-SR3, PN55T45, and PR-Ni70Cr17S4R4 + 20% PT-Al5N with a PT-Al5N under layer. Methodology. The selection of wear-resistant coatings was based on the analysis of the following properties: adhesion strength of the coating to the base material, wear resistance of the coatings, hardness, and porosity. Results. Metallographic analysis of the structure of plasma coatings obtained from powders PG-SR3, PN55T45, and PR-Ni70Cr17S4R4 + 20% PT-All5N with three different plasma heater power levels (10 kW, 15 kW, and 20 kW) indicated that the densest and most reliable coating among those studied is the coating made from PR-Ni70Cr17S4R4 + 20% PT-Al5N powder. Practical value. Therefore, there is no need to increase the heater power beyond 15 kW when spraying this type of powder. The research concluded that when obtaining wear-resistant coatings, the optimal choice is PR-Ni70Cr17S4R4 + 20% PT-All5N powder with a PT-Al5N under layer.

Wear-Resistant Coatings Produced from TiN–TiB2 and TiN–Si3N4 Composites by Electrospark Deposition and Laser Processing

Wear-Resistant Coatings Produced from TiN–TiB2 and TiN–Si3N4 Composites by Electrospark Deposition and Laser Processing

Study on the Effect of Laser Remelting Energy Density on the Microstructure and Wear Resistance of Fe-Based Alloy Coatings Fabricated by Laser Cladding

Study on the Effect of Laser Remelting Energy Density on the Microstructure and Wear Resistance of Fe-Based Alloy Coatings Fabricated by Laser Cladding

A Morphological Study and Effect of Intermediate Phase Formation on Hard and Wear Resistant SiC-Co Composite Coating on Low Carbon Steel via Arc Based Heat Source

A Morphological Study and Effect of Intermediate Phase Formation on Hard and Wear Resistant SiC-Co Composite Coating on Low Carbon Steel via Arc Based Heat Source

Atomic-Scale Description of the Magnetic TiN|FeCo Multilayers.

Motivated by the experimental findings of Wolff et al., we investigated the TiN|FeCo multilayers at the atomic scale. Four different models were employed to investigate the interface, considering both Fe and Co surface terminations of the FeCo compounds. The interface formation energy formalism was employed to study the thermodynamic stability of these models. The results show that an interface mediated by Co atoms is most likely to appear in the experiment. Also, the Fe surface termination is more viable than a Co surface termination. The magnetic moments of Co at the interface are 1.48 μB/atom, which denotes a decay compared to bulk (1.76 μB/atom). Besides, Ti acquires a very small induced magnetization of -0.05 μB/atom. Our proposed atomistic model of the TiN|FeCo multilayer system fits perfectly with the structure obtained in experiments, and it is a step forward in the theoretical-experimental design of wear-resistant coatings with outstanding magnetic and mechanical properties.

Development of a-C:H coatings doped with trimethylsilyl acetate prepared using plasma enhanced chemical vapor deposition

The main aim of the present study was to develop hard a-C:H:SiOx coatings prepared from the unique gaseous mixture of trimethylsilyl acetate (TMSAc) with methane using plasma of RF capacitively coupled glow discharge. Studied coatings were prepared using different methane ratios in TMSAc/CH4 gaseous mixtures ranging from 7.1 % to 85.7 %. Simultaneously, the influence of the power supplied to the discharge (25–100 W) on the properties of resulting coatings was investigated. The presented research work discusses in detail the evolution of chemical composition, mechanical characteristics, and optical properties of resulting coatings depending on variable CH4 ratio and discharge power. Within this study, various materials with the smooth surface structure were achieved. Applying low CH4 ratio and 25 W power led to the formation of soft SiOxCyHz coatings with high content of Si–O and –CH3 groups exhibiting hardness of approx. 0.95 GPa. Gradually increasing the CH4 ratio and discharge power up to the specified limit values (85 % and 100 W, respectively) induced structural changes, resulting in a-C:H:SiOx coatings with a remarkable hardness of 11 GPa and excellent fracture resistance. These attributes are of utmost importance in numerous industrial applications, including anticorrosive coatings, low-friction wear-resistant coatings to prolong the lifetime of car engines, biocompatible coatings, components for plastic molds, as well as parts for optical disc molds and textile machinery.

Effects of Process Parameters on Microstructure and Wear Resistance of Laser Cladding A-100 Ultra-High-Strength Steel Coatings

To improve the hardness and wear resistance of mild steel, A-100 ultra-high-strength steel cladding coatings were prepared on the surface of mild steel by laser cladding. In this study, the effects of laser cladding process parameters on the forming quality, phase composition, microstructure, microhardness and wear resistance of the A-100 ultra-high-strength steel cladding coatings were researched. The results show that the main phase of the coating is martensite and a small amount of austenite. The microstructures of the upper part of the cladding coatings are mainly equiaxed grains, while those of the lower part are mainly columnar grains. With an increase in laser specific energy, the microstructures of the cladding coatings become coarse. When the laser specific energy is 70.8 J/mm2, the microhardness of the cladding coating is the highest, and the maximum average microhardness of the cladding coatings is 548.3 HV. When the laser specific energy is low, the wear of the cladding coatings is mainly pitting, while when the laser specific energy is high, the wear type of the cladding coatings is mainly adhesive wear. Moreover, the microhardness and wear resistance of the cladding coatings are reduced if the laser specific energy is too high.

Influence of TiB2 Incorporation on Microstructural Evolution in Laser-Clad FeCrV15 + TiB2 Deposits

Vanadium carbide (VC)-reinforced Fe-based hard facings are pivotal in enhancing the wear resistance of tools prone to mechanical damage. This study investigates the impact of titanium diboride (TiB2) addition (at varying laser power and powder federate) on the microstructure, hardness, wear resistance, and corrosion resistance of high-carbon ferrochrome FeCrV15 clad coatings for agricultural and mining applications. Laser cladding techniques were employed to deposit coatings on steel substrates, and the samples were subjected to comprehensive material characterization, including microhardness testing, wear studies, and electrochemical polarization. Results reveal that TiB2 addition led to visible reactions during deposition, resulting in decreased hardness compared to pure FeCrV15 coatings. Moreover, TiB2 incorporation adversely affected the anti-corrosion properties of the coatings, although FeCrV15 coatings exhibited superior corrosion resistance compared to FeCrV15 + TiB2 coatings. Tribological evaluations showed that all coatings exhibited better anti-wear capabilities compared to the steel substrate, with varying degrees of improvement influenced by TiB2 concentration and laser beam power. Overall, FeCrV15 deposits demonstrated superior anti-wear and anti-corrosion properties compared to FeCrV15 + TiB2 coatings and attributed to increased convergence of carbide particles and higher grain-boundary density. This research contributes to understanding the intricate interplay between carbide reinforcement and matrix structure in Fe-based hard facings, providing insights for optimizing coating performance in demanding industrial applications.

Effect of WC-10Co-4Cr Reinforcement Amount on Wear and Corrosion Resistance of Fe-Based Amorphous Coatings

Effect of WC-10Co-4Cr Reinforcement Amount on Wear and Corrosion Resistance of Fe-Based Amorphous Coatings

Effect of MoS2 nanoparticles on the properties of Ni-W-SiC composite coatings

To improve the comprehensive protection performances of Ni-W-SiC composite coatings, we successfully manufactured Ni-W-SiC-MoS2 composite coatings using an electrodeposition technique on a 7075 aluminum alloy surface. We analysed the changes in microhardness, wear resistance, corrosion resistance, surface morphology and roughness of the composite coatings upon the addition of MoS2 nanoparticles. A microscopic characterisation of the Ni-W-SiC-MoS2 coatings was carried out by scanning electron microscope and atomic force microscope. The elemental composition was analysed by energy dispersive spectroscopy. The grain size was calculated by X-ray diffraction. The microhardnesses of the Ni-W-SiC-MoS2 composite coatings were evaluated by a microhardness tester, the wear resistance was tested by a rotary friction tester, and the corrosion resistance was evaluated using an electrochemical workstation. The tests indicate that the addition of MoS2 nanoparticles has significant effects on the micromorphology and grain size of Ni-W-SiC,and that they can uniformly codeposit with SiC nanoparticles in the Ni-W coating, exerting a synergistic effect on the improvement in the performance of the composite coating. When the amount of added MoS2 is 8 g/L, the Ni-W-SiC-MoS2 coating has the smallest grain size and highest microhardness (917.6 HV). Its corrosion resistance is considerably improved compared to that of the Ni-W-SiC coating. When the MoS2 concentration is 6 g/L, the Ni-W-SiC-MoS2 coating has the highest content of MoS2 nanoparticles, the friction coefficient reaches the minimum (0.24), and the wear resistance is best.

An improved vision-based tactile skin with imaging adjustment system to reduce defocusing caused by contact depth changes

Imaging robustness of the vision-based tactile sensor (VTS) depends on coating wear resistance and imaging stability. With the miniaturization of sensors, the limited imaging space cannot afford a buffer against imaging deviations caused by contact depth changes. This paper proposes an improved vision-based thin tactile sensor (VTTS, also named vision-based tactile skin), integrating a focus-adjustable camera and an imaging adjustment system (IAS) to improve imaging robustness. The IAS contains an imaging calibration system and a focusing system. Since visuo-tactile sensing is performed in a relatively stable and closed imaging environment, the image-based focusing method is naturally matched with tactile imaging. Accordingly, an imaging calibration system based on a global search is designed to determine the focusing interval and shorten the focusing range. Three-point-fitting-based depth from focus (TPF-DFF) and deep-learning-based depth from defocus (DL-DFD) are proposed for low-frequency (simple)/high-frequency (complex) imaging adjustment. The experimental results demonstrate that the IAS-VTTS has close to 100% adjustment accuracy, and the fastest focusing time is up to 40 ms. Consequently, the IAS-VTTS can adapt to different deformation depths and support high-quality tactile imaging.

Research on cobalt-molybdic sulfide composite coatings deposited by magnetic jet electrodeposition under different magnetic field intensities

Co-MoS2 composite coatings were deposited by the magnetic jet electrodeposition under different magnetic field intensities. The growth orientation and deposition mechanism of Co-MoS2 composite coatings under magnetic jet electrodeposition were analyzed based on the weak adsorption theory of nanocomposite co-deposition. Research showed that the coating topography changed from a blade-like structure to a cellular structure, and the cellular structure became a granular protrusion structure with increase of the magnetic field intensity. Compared with Co-MoS2 composite coating in jet electrodeposition, the orientation of Co shifted from (110) to (101) as the magnetic field intensity increased in magnetic jet electrodeposition. The adhesion, microhardness, adhesion, corrosion and wear resistance of the composite coatings were enhanced, which was attributed to the influence of the magnetic field on the growth orientation of the composite coating and the coordinated lubrication effect in the Co-MoS2 composite coating.

Investigation on tribological properties of high-velocity air fuel spraying WC–Cr3C2–Ni coating on the surface of continuous casting crystallization rollers

To overcome the wear problem of the substrate of thin-strip continuous casting crystallization rollers and improve economic efficiency, high-velocity air fuel (HVAF) technology was used to deposit WC–Cr3C2–Ni wear-resistant coatings on the surface of the crystallization rollers. The existing performance and wear condition of curved WC–Cr3C2–Ni coatings during continuous casting were investigated by the ring-block wear system. The experimental results showed that the WC–Cr3C2–Ni coating with a thickness of 300 μm effectively reduced the coefficient of friction (by 16.4 %) and the wear rate (by 82.5 %) on the surface of the crystallization roller and significantly reduced the roughness of the wear interface (by 71.2 %), which provided reliable protection for the substrate. The results of high-temperature (200 °C) wear tests showed that the WC–Cr3C2–Ni coating deposited via HVAF protected the substrate in actual long-cycle production and exhibited an excellent resistance to the emergence and expansion of failure cracks. This study provided a theoretical basis for the selection and preparation of surface coatings for thin strip continuous casting crystallization rollers.

In Situ Polymerized Self-Healing Microcapsules as Multifunctional Fillers toward Phosphate Ceramic Coatings.

The protective efficacy of chemically bonded phosphate ceramic coatings (CBPC) is notably diminished owing to the presence of micropores and inadequate self-healing capacity in prolonged corrosive environments. Consequently, it is imperative to augment the corrosion and wear resistance of phosphate ceramic coatings while imbuing them with self-healing capabilities. In this work, a novel self-healing phosphate ceramic coating (MC-PTx@CBPC, x = 0.5, 1.0, 1.5) is designed by urea-formaldehyde (UF) in situ polymerization of nanoscale microcapsules encapsulated with 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES) and evaluated in detail for corrosion and wear resistance. The corrosion inhibition efficiencies of all formulated MC-PTx@CBPC (x = 0.5, 1.0, 1.5) coatings exceed 90%, with the impedance modulus at the lowest frequency (|Z|f=0.01) showing enhancements of 1-2 orders of magnitude compared to pure CBPC. Moreover, the self-healing function becomes active during prolonged immersion. This can be primarily ascribed to the formation of a unique micronanostructure facilitated by nanoscale microcapsules and micrometer-sized alumina ceramics, bonded via the AlPO4 phase. This structure enhances both the hydrophobicity and the bonding strength of the coating. Specifically, following prolonged immersion, the encapsulated PFDTES is liberated from the microcapsules, undergoing hydrolysis and subsequent polymerization upon contact with the electrolyte to form a protective thin film. This film efficiently obstructs the ingress of corrosive agents. Furthermore, the special micronanostructure enhances the hardness of the coating and the releasing PFDTES can form a lubricating film at the interface of abrasion, thus reducing the wear rate and friction coefficient of the MC-PTx@CBPC (x = 0.5, 1.0, 1.5). Therefore, MC-PTx@CBPC (x = 0.5, 1.0, 1.5) possesses excellent corrosion protection, tribological properties, and self-healing capabilities, which provide thought-provoking ideas for phosphate ceramic coatings to protect metals in harsh environments.

Elastic and Elastoplastic Contact Mechanics of Concentrated Coated Contacts

Machines operate under increasingly harsher contact conditions, causing significant wear and contact fatigue. Sub-surface stresses are responsible for the premature contact fatigue of rolling element bearings, meshing gears, and cam–follower pairs. Surface protection measures include hard, wear-resistant coatings. Traditionally, contact integrity has been predicted using classical Hertzian contact mechanics. However, the theory is only applicable when the contact between a pair of ellipsoidal solids of revolution may be considered as a rigid indenter penetrating a semi-infinite elastic half-space. Many coatings act as thin bonded elastic layers that undergo considerably higher pressures than those predicted by the classical theory. Furthermore, inelastic deformation of bonded solids can cause plastic flow, work-hardening, and elastoplastic behaviour. This paper presents a comprehensive, integrated contact mechanics analysis that includes induced sub-surface stresses in concentrated counterformal finite line contacts for all the aforementioned cases. Generated pressures and deformation are predicted for hard coated surfaces, for which there is a dearth of relevant analysis. The contact characteristics, which are of particular practical significance, of many hard, wear-resistant advanced coatings are also studied. The paper clearly demonstrates the importance of using efficient semi-analytical, detailed holistic contact mechanics rather than the classical idealised methods or empirical numerical ones such as FEA. The novel approach presented for the finite line contact of thin-layered bonded solids has not hitherto been reported in the open literature.

Comparison of microstructure, mechanical, and electrochemical performance of laser-deposited FeCrV15 alloy at varying powder feed rates

In the realm of surface modification, repair, and reinforcement of components exposed to challenging operational conditions, such as tillage tools, laser cladding stands out as an innovative manufacturing technique. Employing this additive manufacturing approach, a functionally graded material with outstanding strength and properties is incorporated to enhance the desired attributes of the base material. This comparative investigation scrutinized and assessed the microstructural characteristics, hardness, wear resistance, and corrosion behavior of high carbon ferrochrome FeCrV15 coatings fabricated at two distinct powder feed rates, namely 5 and 6 g/min, respectively. The analysis delved into how the resultant coatings' molten bead deposition, microstructural evolution, hardness, wear resistance, and corrosion resistance were influenced by the powder feed rate. Evaluation of hardness was conducted using a Vickers microhardness testing apparatus, while phase identification was accomplished utilizing an X-ray diffractometer. The morphologies of the microstructures were scrutinized employing optical microscopy and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS). Furthermore, the corrosion response of the deposits in a soil–water environment was probed utilizing an Autolab potentiostat. A comprehensive assessment of the coatings' sliding wear performance was undertaken using an Anton Paar Tribometer. The findings of the study reveal that an escalation in the powder feed rate engenders heightened grain refinement within the microstructure, yielding a defect-free sample and augmenting the wear performance (with a wear rate of 2.42 × 10–6 mm3/N/m for sample B, surpassing 2.39 × 10–5 mm3/N/m for sample A and outstripping 1.72 × 10–3 mm3/N/m for the steel substrate). Additionally, the corrosion resistance is enhanced (with a corrosion rate of 0.0032 mm/yr for sample B, surpassing 0.0036 mm/yr for sample A, which, in turn, exceeds 0.1168 mm/yr for the steel substrate) in the case of sample B.

Nucleation mechanism, particle shape and strengthening behavior of (Ti, Nb) (C, N) particles in Fe-based composite coatings by plasma spray welding

This study aimed to determine the nucleation mechanism, particle shape, and strengthening behavior of (Ti, Nb) (C, N) particles in Fe-based composite coatings. In this study, an in-situ technique combined with a plasma spray welding process was proposed to obtain a coating with in-situ (Ti, Nb) (C, N) particles. Composite coatings were successfully prepared on low-alloy steel by plasma spray welding using a mixture of Fe-based, Ti and Nb powders. N gas was used to provide the N atoms. The microstructural analysis results indicated that the reinforced particles transformed from irregular dendritic into massive and spherical particles, and then into spherical and lath particles, as the atomic ratio of Ti/Nb decreased. During solidification, TiN nucleated preferentially and Ti (C, N) particles were formed sequentially. Subsequently, NbC nucleated and grew with Ti (C, N) as its core, and (Ti, Nb) (C, N) particles were formed at the end. The microhardness values of these composite coatings were 680–970 HV, whereas that of low-alloy steel was 174 HV. The wear resistance of the composite coatings increased as the Ti/Nb atomic ratio decreased. The composite coating had the highest average microhardness and the best wear resistance when Ti/Nb = 1:3. Its average microhardness was five times more than that of the low-alloy steel. In addition, the mass loss of the composite coating was 0.4 mg, which is only one-sixth that of the low-alloy steel (2.4 mg). The main reason for this was the in-situ formation of (Ti, Nb) (C, N) particles, which were evenly distributed in the composite coatings.

Machining of Ni-based superalloys using CAPVD coated carbide tools

The ever-increasing demand for cost-effective machining of Ni (Nickel) based superalloys has made it necessary to explore nanocomposite coatings as a potential surface engineering solution. The present study aims to investigate the variation in machining performance of new-generation hard wear-resistant coatings in milling of IN 718 (Inconel 718), IN 625 (Inconel 625), and IN 617 (Inconel 617). TiAlSiN and CrAlSiN coatings were grown in-house over tungsten carbide (WC) milling inserts through the cathodic-arc PVD route. The TiAlSiN coating improved the tool life by 80 % and 60 % in the case of IN 718 and IN 625, respectively. However, in the case of IN 617, the TiAlSiN-coated tool could not even reach the uncoated tool life. The CrAlSiN coating, on the other hand, improved the tool life by more than 200 % in the milling of IN 617. Tool-chipping was the dominant failure mode among all observed, which included flank wear and workpiece adhesion. The repeated adhesion and removal of the workpiece layer from the tool surface was a major cause of tool failure. The coating layer delayed the initiation of the chipping and prolonged the flank-wear-dominated machining time, resulting in improved tool life. The wear resistance of coatings in machining different workpiece materials was greatly influenced by the relative affinity of constituting elements of workpieces for employed coatings. The machining chips exhibited shear bands and saw-tooth (serrated/segmented) morphology in almost all cases. The degree of segmentation showed a direct correlation with tool life. The present work helps identify the optimum coating and machining conditions for three different grades of Ni-based superalloys. Additionally, the underlying mechanisms were analyzed and discussed with scientific observations.

Microstructure Evolution and Enhanced Wear Resistance of Al2CrFeNiMo High Entropy Alloy Coating Fabricated by Laser Cladding

Microstructure Evolution and Enhanced Wear Resistance of Al2CrFeNiMo High Entropy Alloy Coating Fabricated by Laser Cladding

Comparison of Microwave Versus Conventional Furnace Heat Treatments of Carbide Composite Thermal Spray Coatings

Thermal spraying has become an industrial standard in the production of wear-resistant WC-Co and Cr3C2-NiCr composite coatings. However, generating optimum wear-resistant nano-reinforced carbide microstructures within the coatings remains challenging. The alternative two-step approach in this work involves coating formation under high energy conditions to generate maximum carbide dissolution, followed by heat treatment to precipitate nanocarbides. Microwave heating of particulate materials has been reported to offer several benefits over conventional furnace heating, including faster heating rates, internal rather than external heating, and acceleration of reactions/phase transformations at lower temperatures. This novel work explored the use of microwaves for heat treatment (as distinct from melting) of WC-Co and Cr3C2-NiCr thermal spray coatings and contrasted the rate of phase development with that from conventional furnace treatment. Coatings were successfully microwave heat-treated to generate the same phase composition as furnace treatment. Both treatments generated comparable results in the Cr3C2-NiCr system. The WC-Co system achieved a much more crystalline structure in a dramatically shorter time relative to the conventional furnace-treated sample. The results are contrasted as a function of material and microstructure interaction with microwaves and the critical phase transition temperatures to account for the observed responses.