Improved Wear Resistance Research Articles

Microstructural, tribological, and corrosion behavior of B4C-added TiO2 coatings applied on 316 L stainless steel via sol-gel method

Corrosion protection of metals is essential for a wide range of technological applications, and coating metal surfaces with protective materials is a commonly employed method to achieve this. Among these, TiO2 coatings are extensively used due to their excellent photocatalytic properties, their applications in sensing and solar cells, and enhancing the corrosion and wear resistance of metal surfaces. Recent advancements have focused on the incorporation of carbide particles, such as B4C, to further improve the performance of TiO2 coatings. In this study, TiO2 coatings containing 0–3.25 wt% B4C were applied to a 316 L stainless steel substrates using the sol-gel method. The coatings were characterized by XRD and SEM-EDS analyses, and their wear and corrosion properties were evaluated using ball-on-disc wear tests and corrosion tests in NaCl solutions. The results demonstrated that lower concentrations of B4C led to improved wear resistance, likely due to the formation of a durable tribolayer, while higher concentrations reduced the wear resistance, attributed to increased oxidation and the formation of brittle phases. Corrosion resistance was enhanced in coatings containing 0.25 wt% and 1.25 wt% B4C, which can be attributed to the formation of protective B2O3 phases. However, at higher B4C concentrations, the corrosion rate increased, primarily due to the presence of cracks in the coating structure. Overall, the addition of 0.25 wt% B4C to the TiO2 coating significantly improved wear and corrosion resistance, indicating its potential as an effective additive for protective coatings.

Microstructure, hardness, and tribological properties of Ni-Co/ SiO2 nanocomposite coating produced through pulsed current electrodeposition

This study investigates the development of Ni-Co/SiO2 nanocomposite coatings on mild steel surface using pulsed-current electrodeposition method. The effects of incorporating SiO2 nanoparticle and varying its concentration on the coatings' microstructure, microhardness, wear resistance, and frictional properties were assessed using field-emission electron microscopy, X-ray diffraction, Vickers microhardness testing, and dry sliding wear tests. The results indicated that the coatings exhibited two-phases of Ni-Co solid solution (α) with a face-centered cubic (FCC) crystal structure and hexagonal Co, a refined crystallite size of approximately 31 nm for Ni-Co and about 25 nm for Ni-Co/SiO2, along with a colony-like morphology that did not show any preferred growth direction. The amount of Ni-Co solid solution increased with the addition of SiO2 nanoparticles. The composite coatings demonstrated enhanced microhardness of 581 HV, which is 52 % greater than that of the Ni-Co coating, as well as improved wear resistance and a reduced friction coefficient compared to the unreinforced alloy coating. However, higher SiO2 content adversely impacted the tribological properties due to nanoparticle agglomeration. Analysis of the worn surfaces revealed a transition from abrasive wear to oxidative wear with increasing applied force for the coatings.

Low friction characteristics and tribochemistry analysis of novel AlTiN/a-C based nanocomposite coatings

Friction reduction of AlTiN-based hard coatings is gaining much attention among researchers worldwide to broaden their tribological applications. Metal/non-metal inclusions, as well as the design of a novel coating architecture, are primarily focused on reducing friction while retaining wear resistance. This study investigates the tribological characteristics of magnetron sputtered AlTiN coatings by incorporating amorphous carbon (a–C) at different concentrations (5–25 at.%), as well as the compositionally graded AlTiN/a-C coatings (CGC). The XPS and Raman spectroscopy results confirm the presence of a-C features, while XRD reveals the formation of ceramic carbide phases in AlTiN coatings with higher carbon content and CGC coatings. The CGC AlTiN/a-C have shown a maximum hardness of 34.3 GPa and an elastic modulus of 321 GPa due to their refined grain structure. The CGC had the lowest friction (0.18 at 300 K and 0.37 at 673 K), as well as improved wear resistance (2.74 × 10−7 mm3/Nm (300 K) and 4.93 × 10−7 mm3/Nm (673 K)). The tribolayers are found to be mainly composed of sp2/sp3 bonded a-C features (including C=C/C─C, C─N, and C─O), which reduces the friction force significantly. The CGC AlTiN/a-C coating has exhibited improved wear resistance behavior due to their finely grained structure and improved mechanical properties.

Synthesis of rice‐granular bimetallic nickel/iron phyllosilicates to simultaneously lubricate and strengthen the epoxy‐based composites

AbstractTo improve the subpar lubricating performance of epoxy resin, this paper presents the preparation of a novel bimetallic phyllosilicate featuring a distinctive rice‐granular morphology, which incorporates nickel and iron metal cations through a facile hydrothermal process. These phyllosilicates were then integrated into the epoxy matrix to form composites. A comprehensive analysis of the target product validates the rationality of the synthesis strategy for the as‐prepared rice‐granular bimetallic nickel/iron phyllosilicate, demonstrating a homogeneous hierarchical structure with numerous tiny nanosheets of nickel/iron phyllosilicate grown in situ on the flat surfaces of the rice‐granular metal–organic frameworks. An adequate addition of nickel/iron phyllosilicates allows for excellent dispersion within the matrix and establishes strongly bonded interfaces, steadily increasing the elastic modulus and hardness. Notably, the average friction coefficients decrease from 0.515 for the pure resin to 0.450 for the composites when the filler content reaches 7%, indicating a significant solid lubrication effect. In contrast, adding just 1% nickel/iron phyllosilicate moderately improves wear resistance, elongation at break, and tensile strength. Furthermore, it was found that as the filler content increased, the weight loss rate was reduced by approximately 43.8%, while the residual char increased by 74.2%, significantly enhancing the thermal stability of epoxy composites at high temperatures. This study offers a promising approach to preparing self‐lubricated epoxy composites with favorable mechanical and thermal properties.Highlights NiFePS was successfully synthesized via a facile two‐step self‐polymerization. Excellent mechanical properties of composites could be achieved with low content of NiFePS. The friction coefficient and wear rate were lowered remarkably. The friction mechanism was solid lubrication.

Investigation of mechanical properties and high temperature wear resistance of CoFeNi1.5VZr0.4Six high entropy alloys optimized by Si alloying

The current work studies the mechanical properties and high-temperature wear resistance of CoFeNi1.5VZr0.4Six high entropy alloys by Si alloying. The Si alloying transforms Ni7Zr2 into a more wear-resistant silicide phase, and the microstructure changes from lamellar eutectic structure to dendritic structure. The high temperature microhardness, compressive strength and fracture toughness of the HEAs increase first and then decrease with the increasing Si content. The Si alloying in HEAs brings about significant improvements in wear resistance at elevated temperature through the combined effects of phase structure modifications and compositional changes in the tribo-layer. The augmented mechanical properties of the worn subsurface layer contribute to improved wear resistance at elevated temperatures.

Generation of self-healing and sliding wear resistant titanium surfaces by different pico-second laser induced periodic surface structures

Selective and complete micro-patterning (μ-patterning) of α‑titanium surfaces were performed using a 1064 nm laser system. With a fluence of 0.6 J⋅cm−2 and a pulse duration of 10 ps, two different μ-patterns of laser induced periodic surface structures (LIPSS) were generated by mainly changing the number of pulses per spot and the spot-to-spot distance. A high number of pulses per spot and a large spot-to-spot distance of 60 μm gives selectively with LIPSS modified dimples. Their spatial period varies from 159 nm to a maximum of 620 nm inside the dimples. An increased fraction of TiO2 in the crystalline form of rutile gave improved wear resistance and a coefficient of friction COF of 0.20 ± 0.02. If the spot-to-spot distance is reduced to 6 μm and the number of pulses at one spot remains low, a completely rippled surface with slightly increased oxide fraction but still a metallic plastic behaviour was able to show volume expansion during sliding. The observed self-healing ability of this LIPSS pattern is correlated with the relief of compressive stresses in this study. As volume expansion operates against the sliding motion of the diamond tip, high COFs of 0.62 ± 0.11 for a normal load of 1.0 N and 0.45 ± 0.04 for a normal load of 0.5 N were measured. After further optimisation, such a tailored increase in COF and load stimulated volume expansion of the surface could be useful in order to act against implant loosening and undesired movements.

Carbon effect on tensile and wear behaviors for a dual-phase Fe61.5Cr17.5Ni13Al8 alloy

High entropy alloys (HEAs) series were produced by doping carbon into Fe61.5 Cr17.5Ni13-xAl8Cx (x = 0, 0.25, 0.5, and 1.5 at.%) by a vacuum arc melting. The carbon doping effect on the phase composition, mechanical properties, and wear behavior was studied. Fe61.5 Cr17.5Ni13Al8 alloy microstructure was a heterogeneous structure comprising FCC, BCC, and B2 phases. By introducing carbon into Fe61.5 Cr17.5Ni13-xAl8Cx (x = 0, 0.25, 0.5, and 1.5 at.%), the BCC phase fraction increased with decreasing FCC phase during annealing, accompanied by the formation of M23C6-like carbides at temperatures of 800 °C and 900 °C. The carbon-doped HEAs exhibited enhanced mechanical properties compared to the carbon-free HEAs, including higher tensile strength (1580 MPa), notable ductility (∼20 %), reduced friction coefficient (0.50), and improved wear resistance. Among the carbon-doped HEAs, the HEA with x = 0.5 at.% and annealed at 800 °C demonstrated exceptional wear resistance due to the compensations of attaining a balance between strength and elasticity.

Current-carrying tribological behavior and wear mechanism of CuW composites with different W content

CuW composites are widely used in the field of electrical contacts, such as high-voltage switch and microelectronic devices, and the service life of the key components is directly affected by its wear resistance and corrosion resistance. In this paper, the effects of loading current on the tribological behavior of CuW composites with different W content were studied, focusing on the variation of friction coefficient during friction, wear rate and the wear topography of the surface after friction, and the wear mechanism was discussed. The results indicate that the friction coefficient of CuW composites was larger under energized conditions than under dry friction conditions, and that the friction coefficient first increases and then decreases with the increasing current. The main reason for the decrease in friction coefficient is that the heat generated by increasing current creates a layer of molten lubricant on the contact surface. In addition, the wear rate of the CuW composites decreased as the W content increased. When loaded with a current of 15 A, the CuW80 composites exhibited the lowest wear rate of 8 × 10−3 mg/m, which was attributed to the improved wear resistance due to the ability of the high W content to resist plastic deformation. The wear forms of CuW composites under current loading include adhesion, abrasive wear and arc erosion, and fatigue wear was also associated with long-term high current conditions.

Surface modification of Al-15Al2O3-0.3G powder metallurgical alloy induced by high-current pulsed electron beam

This paper investigates the effect of high-current pulsed electron beam (HCPEB) surface treatment with two, five, and eight pulses on Al-15Al2O3-0.3G prepared by powder metallurgy. The results show that the presence of graphene during HCPEB irradiation effectively controls the extension of microcracks. The surface hardness of the samples increased by 66.56% and the wear rate decreased by 68.98% after eight-pulse HCPEB treatment. The increase in hardness is attributed to the uniform dispersion of hard particles, fine grain strengthening, dislocation strengthening, and amorphous structure formation by XRD, SEM, and TEM analysis during HCPEB irradiation. The improvement in wear resistance was attributed to the increase in hardness. The corrosion current density in 5 wt. % NaCl solution decreased from 1.212 × 10−4 to 3.353 × 10−5 after eight-pulse HCPEB treatment; the improved corrosion resistance performance is attributed to the equilibrium structure induced by HCPEB treatment.

Sustainable lubrication through Gd DLC films and ionic liquids for wear and corrosion resistance

This study examines the integration of ionic liquids (ILs) with gadolinium diamond-like carbon (Gd-DLC) films as a means of addressing the environmental drawbacks associated with conventional additives, such as zinc dialkyldithiophosphates. Tribological testing initially revealed that higher concentrations of gadolinium in the DLC resulted in improved wear resistance. Further observation of the wear tracks confirmed no corrosion typically seen in steel under bromide-containing ILs, thereby demonstrating the protective capabilities of Gd-DLC. Advanced surface analysis techniques revealed that increased gadolinium content enhances phosphate adsorption, resulting in the generation of protective tribofilms. These findings indicate that Gd-DLC and ILs have the potential to develop sustainable and efficient lubrication systems, significantly enhancing both performance and environmental compatibility of mechanical applications.

The Influence of Cryogenic Treatment on the Tribological Properties of Tungsten Carbide

Improvement in wear resistance and hardness of cutting tool material is one of the most critical challenges in machining operations. This issue can be addressed by enhancing wear resistance and hardness through cryogenic treatment of tungsten carbide. This study investigates the effect of different soaking periods during cryogenic treatment on commercially available tungsten carbide. Experiments were conducted at a temperature of 88K with varying soaking periods of 8 hours, 20 hours, 24 hours, and 30 hours. To quantify and confirm the impact of different soaking periods on hardness and wear resistance, Rockwell hardness measurements and weight loss during wear tests were performed. The results indicate a significant decrease in weight loss for the sample soaked for 8 hours compared to other soaking periods, although there was no change in bulk hardness. The reduced weight loss during the sliding wear test suggests that cryogenically treated tungsten carbide exhibits improved wear resistance due to an increased population density of carbides. Microstructural analysis of the worn surface reveals the mechanism behind the enhanced mechanical properties. Key Words: Cryogenics, dct, sct, microstructure, soaking period, tool life.

Decarburization control and performance enhancement: Optimizing HVOF sprayed submicron WC-12Co coating with additives

This study explored enhancing WC-12Co coatings' performance and preventing decarburization by adding Cr, Cr3C2, and VC. Coatings were prepared using HVOF technology, and their microstructure, mechanical properties, wear behavior, and corrosion resistance were analyzed. Results indicated that VC and Cr3C2 add-ins effectively prevented decarburization, with T2 coatings (WC-12Co-2VC-2Cr3C2) showing lower porosity, higher hardness, and improved wear resistance. However, T1 coatings (WC-12Co-2VC-2Cr) demonstrated superior corrosion resistance due to Cr addition. The findings provide insights into the additives' effects on WC-12Co coatings and underscore the potential of VC and Cr3C2 as decarburization inhibitors.

Influence of Cu and Si on the microstructure and properties of CoCrFeNiCu1-xSix alloys

The effect of Cu and Si on the microstructure and properties of CoCrFeNiCu1-xSix alloys (x = 0, 0.2, 0.5, 0.8 and 1) was studied in this work. The results indicate that as the x value increased from 0 to 1, the phase compositions of CoCrFeNiCu1-xSix alloys evolved from FCC + Cu-rich phases to FCC + Cu-rich + NiSi-rich phases to FCC + BCC + NiSi-rich phases. Therefore, the decrease in Cu content led to the decreasing Cu-rich phase content, whereas Si addition not only favored the formation of intermetallic compounds, but also promoted the phase transition from FCC to BCC. Due to the competition between BCC phase suppressing corrosion and Cu-rich + NiSi-rich phases inducing galvanic corrosion, the corrosion resistance of CoCrFeNiCu1-xSix alloys improved with the increasing x value. The microstructure change also resulted in an improvement in hardness and wear resistance, and a deterioration in fracture toughness of CoCrFeNiCu1-xSix alloys. Moreover, the main wear mechanism evolved from adhesive wear and abrasive wear to slight abrasive wear. Comparison among five alloys indicates that Cu0.2Si0.8 alloy exhibited the excellent comprehensive properties, revealed by the corrosion current density of 4.81 × 10−8 A/cm2, the hardness value of 510.5 HV, the fracture toughness of 8.57 MPa·m1/2 and the wear rate of 0.88 mm3·N−1 · m−1.

Significantly lowering friction and wear of CoCrNi medium-entropy alloy film via massive interstitial carbon-induced amorphization

CoCrNi medium-entropy alloy (MEA) exhibits exceptional damage-tolerance, particularly at cryogenic temperatures, but demonstrates poor wear resistance. In this study, we propose a strategy to significantly reduce friction and wear of CoCrNi MEA film through the introduction of massive interstitial carbon-induced amorphization. The microstructure of as-sputtered CoCrNi film reveals an anisotropic columnar nanograin structure, featuring a primary face-centered-cubic (fcc) phase and a minor hexagonal-close-packed (hcp) phase. Upon the introduction of 16 at.% interstitial carbon (CoCrNi-C), a remarkable phase transformation occurs, resulting in an isotropic amorphous structure. Under low-load and low-sliding-velocity conditions, the CoCrNi-C film exhibits a 21% reduction in coefficient of friction (CoF) and 17% reduction in wear rate. More notably, when subjected to higher loads and sliding velocities, the CoCrNi film experiences rapid failure within the initial 100 cycles, manifesting as microcracks, breakage, and peeling. In contrast, the amorphous CoCrNi-C film demonstrates remarkable durability, sustaining over 5000 cycles without failure. The wear rate exhibits a negative correlation with load but a positive correlation with sliding velocity. This enhanced wear resistance can be attributed to the amorphous nature of the CoCrNi-C film, which inhibits local strain accumulation, preventing strain localization that typically leads to crack initiation and propagation in the CoCrNi film. Additionally, the formation of a protective oxide layer contributes to the improved wear resistance of CoCrNi-C film under higher loads and lower sliding velocities. This study provides valuable insights into the design of wear-resistant CoCrNi-based MEA coatings through massive interstitial carbon-induced amorphization.

Influence of the current density on the properties of electrodeposited Ni-W- Ti2AlC composite coatings

In this work, Ni-W-Ti2AlC composite coatings with anti-wear and anti-corrosion abilities were prepared using direct current electrodeposition. The study primarily focuses on the influence of different current densities on the structure and properties of Ni-W-Ti2AlC composite coatings. The microstructural, mechanical properties, and electrochemical performances were studied by using SEM, XRD, EDS, and Tafel polarization techniques. The results indicated that Ti2AlC is successfully co-deposited into the Ni-W coating, and the average grain size of the Ni-W-Ti2AlC composite coating is 15.2 nm. The significant improvement in hardness, wear resistance, and corrosion resistance of Ni-W-Ti2AlC composite coating is attributed to the effects of solid solution strengthening and the uniform distribution of the microstructure. The suitable current density has a great influence on the properties. The microhardness of Ni-W-Ti2AlC composite coatings was increased by 99.59% at a current density of 5 A dm−2 compared to 3 A dm−2. At the same time, the friction coefficient decreased by 13.89%.

Investigation of microstructure, mechanical, and tribological properties of MoSi2-reinforced copper-graphene composites

The MoSi2-reinforced copper-graphene composites (Cu-MoSi2-GNS) were prepared using mechanical ball milling and spark plasma sintering techniques. The effects of MoSi2 content on the microstructure, electrical conductivity, mechanical performance, and tribological properties were systematically investigated. Results indicate that the addition of MoSi2 significantly enhanced strength and hardness, although slightly reducing electrical conductivity. When the MoSi2 content does not exceed 5 wt%, MoSi2 is uniformly dispersed, refining copper matrix grains and improving GNS dispersion. Optimal MoSi2 addition facilitates the formation of a stable subsurface structure with complete mechanical mixture layer, improving wear resistance and self-lubricating properties. The main wear mechanism shifts from adhesive to abrasive wear. At 5 wt% MoSi2, the Cu-MoSi2-GNS composites exhibits superior mechanical properties, electrical conductivity, and tribological performance.

Enhanced tribological properties and the microstructure evolution of the gradient nanostructured copper alloy

In this work, the effects of the gradient microstructures by surface mechanical attrition treatment (SMAT) on the corresponding tribological properties of the nanoprecipitates strengthened copper alloy was investigated. The nanoprecipitates strengthened copper alloy possesses a decent tribological properties compared with the pure copper and bronze. The SMAT-processed NP&T alloy possesses distinctly lower coefficients of friction (COF) than its coarse-grained counterpart throughout the entire frictions. In particular, under a sliding load of 2 N, NP&T alloy possesses a lower COF of 0.58 ± 0.03, approximately 15% lower than that of its homogeneous counterpart. Additionally, the wear volumes, wear rates, and worn surface roughness were approximately 45% lower in the NP&T alloy, indicating the superior tribological properties. The macro-, micro-, and atomic-scale friction and wear mechanisms in the worn NP&T alloy were systematically determined. The inherent gradient nanostructures could achieve strain delocalization, thereby suppressing surface deformation and improving wear resistance. Wear-induced substructure in the NP&T alloy comprises gradient layers mediated by twinning and stacking faults combined with nanocomposite layers, resulting in novel tribological performance characteristics. Thus, combining inherent and newly formed wear-resistant gradient nanostructures is an effective design strategy for high-performance Cu alloys.

Periodic renucleation as an approach to improving the tribological properties of CVD diamond films

This study investigates an approach to enhancing the tribological properties of CVD diamond films by modifying their structure. The approach is based on periodic renucleation of the film during the synthesis process. A comparative analysis was conducted with films of a microcrystalline structure and a standard multilayer structure, consisting of alternating microcrystalline and nanocrystalline diamond layers. The results demonstrate that the periodically renucleated diamond film retains all the features of the multilayer structure, including low surface roughness of 311 nm, tensile residual stress of 2.8 GPa, low coefficient of friction of 0.08, and low wear rate of counter body of 2.19 × 10−6 mm3N−1m−1. Moreover, the periodically renucleated diamond film exhibits significantly improved wear resistance, with a 43 % lower wear rate compared to standard multilayer film.

Characterization, impact and wear properties of treated and as-received graphene nanosheets reinforcement in epoxy resin composites

PurposeThis study aims to explore the enhancement of mechanical properties in epoxy resin composites through the incorporation of graphene nanoparticles, focusing on their impact and wear resistance. It investigates the role of graphene, both treated and untreated, as a reinforcing agent in composites, highlighting the significance of nanoparticle dispersion and surfactant treatment in optimizing mechanical performance.Design/methodology/approachEmploying a novel dispersion technique using a drawing brush, this research contrasts with traditional methods by examining the effects of graphene nanoparticle concentrations treated with surfactants – Polyvinylpyrrolidone (PVP) and Sulphonated Naphthalene Formaldehyde (SNF) – on the mechanical properties of epoxy resin composites. The methodology includes conducting a series of impact and wear tests to assess the influence of graphene reinforcement on the composites' performance.FindingsThe findings reveal a marked enhancement in the composites impact resistance and energy absorption capabilities, which escalate with an increase in graphene content. Additionally, the study demonstrates a significant improvement in wear resistance, attributed to the superior mechanical properties, robust interface adhesion and effective dispersion of graphene. The use of surfactants for graphene treatment is identified as a crucial factor in these advancements, offering profound insights into the development of advanced composite materials for diverse industrial uses.Originality/valueThis study introduces a unique dispersion technique for graphene in epoxy composites, setting it apart from conventional methods. By focusing on the critical role of surfactant treatment in enhancing the mechanical properties of graphene-reinforced composites, it provides a novel insight into the optimization of impact and wear resistance.

Friction and Wear Behavior of Double-Walled Carbon Nanotube-Yttria-Stabilized ZrO2 Nanocomposites Prepared by Spark Plasma Sintering.

Double-walled carbon nanotube-yttria-stabilized ZrO2 nanocomposites are prepared by a mixing route followed by Spark Plasma Sintering. The double-walled carbon nanotubes (DWCNTs) have been previously subjected to a covalent functionalization. The nanocomposites present a high densification and show a homogenous dispersion of DWCNTs into a matrix about 100 nm in size. The DWCNTs are well distributed at the matrix grain boundaries but form larger bundles upon the increase in carbon content. The Vickers microhardness of the nanocomposites decreases regularly upon the increase in carbon content. Incorporation of carbon at contents higher than 2 wt.% results in significantly lower friction coefficients, both against alumina and steel balls, possibly because of the elastic deformation of the DWCNTs at the surface of the sample. Their presence also favors a reduction of the steel/ceramic contacts and reduces the wear of the steel ball at high loads. DWCNTs improve wear resistance and reduce friction without incurring any severe damage, contrary to multi-walled carbon nanotubes.