Adhesive Wear Research Articles

Microstructure, wear behaviour and laser ablation behaviour of double glow plasma alloyed Ta[sbnd]W coating

TaW alloy is considered a crucial candidate for barrel protective coatings due to its high melting point, excellent high-temperature performance, and ablative resistance. In this study, TaW coating was deposited on the surface of PCrNi3MoVA gun steel by double glow plasma alloying (DGPA) technique. The morphology, phase structure, wear property, and laser ablation behaviour of the TaW deposited coating was studied and analyzed by means of scanning electron microscope (SEM), energy dispersive spectroscopy detector (EDS), X-ray diffractometer (XRD), ball-on-disk friction test, and laser pulse heating experiment. The results showed that the coating was dense and metallurgically bonded to the substrate. The coating was primarily composed of the α-Ta phase, and W was solidly dissolved in the Ta to form a mutual solution with solid-solution strengthening effect. The wear mechanisms of TaW coating were adhesive wear and oxidative wear. During the laser pulse heating (LPH) process, the transition region, center region, and splash region appeared successively in the ablation area of the coating. After 10 s of ablation, only a region with a diameter of 0.1 mm was penetrated, highlighting the effective protective role of the TaW infiltrated layer on the substrate.

Supersonic plasma-sprayed TiO2 coating: Performance optimization based on response surface methodology and tribological properties

This study investigated the microstructure and tribological performance of TiO2 coating prepared through the plasma-spraying of TiO2 on an aluminum alloy (ZL109) surface. Box–Behnken design was employed to calculate the optimal spraying parameters (spraying current: 439 A, spraying voltage: 129 V, and Ar flow rate: 117 m3/h). High-temperature tribological characteristics (T = 120 °C) were examined under varying loads (F = 100 N, 120 N, and 140 N). The scanning electron microscopy and energy-dispersive X-ray spectroscopy analysis results revealed that the coating porosity decreased from 3.31 % to 0.31 % with the increase in the spraying voltage from 120 V to 130 V. Both powder and coating exhibited consistent elemental composition (Ti, O) and phase composition (TiO2, TiO, Ti2O3). During the spraying process, part of the powder was oxidized. The average coefficient of friction of the coatings varied from 0.05 to 0.08, and as the load increased, the wear mechanism of the coating changed from abrasion to adhesive wear and oxidation.

Effects of W element on the microstructure, wear and cavitation erosion behavior of CoCrFeNiMnWx high entropy alloy coatings by laser cladding

CoCrFeNiMnWx (x = 0, 0.5, 1, 1.5, 2) high entropy alloy (HEA) coatings were prepared on the surface of 304 stainless steel (304 SS) by laser cladding technology. The effects of W addition on the microstructure, microhardness, friction and wear properties, and cavitation erosion (CE) resistance of the coatings were thoroughly studied. The results show that the phase structure of the CoCrFeNiMnWx HEA coatings exhibits FCC structure, and the microstructure is typical dendrite (DR) and inter-dendrite (ID) morphology. With the increase of W content, the average grain size of CoCrFeNiMnWx HEA coatings gradually decreases. The microhardness of CoCrFeNiMnWx HEA coatings increases first and then decreases due to the brittle cracking caused by the excessive addition of W element. The wear resistance of CoCrFeNiMnW1 HEA coating is the highest, and its wear rate is much lower than that of CoCrFeNiMn HEA coating without W addition. The wear mechanism of CoCrFeNiMnWx HEA coatings is mainly adhesive wear, abrasive wear and oxidation wear, and the fatigue wear mechanism appears on CoCrFeNiMnW2 HEA coating. In addition, CoCrFeNiMnW1 HEA coating displays the highest CE resistance, and its mass loss after CE in 3.5 wt%Nacl solution is lower than that of CoCrFeNiMn HEA coating. The appropriate addition of W element can effectively improve the resistance to wear and CE of CoCrFeNiMnWx HEA coatings, showing a great potential in improving the service lifespan of overflow parts in marine environment.

The tribocorrosion behavior of the (AlCoCrFeNi)x/(WC–10Co)1-x composite coatings produced via high velocity oxy-fuel thermal spraying

The (AlCoCrFeNi)x/(WC–10Co)1-x, (x = 100 wt%(HW1), 75 wt%(HW2), 50 wt% (HW3)) composite coatings are fabricated on 3Cr13 martensite stainless steel using high velocity oxy-fuel (HVOF) spraying technology, and the tribocorrosion experiment is carried out in artificial seawater. The tribocorrosion mechanism of the coatings and counterbody are analyzed. Particularly, the synergistic effect of corrosion and wear is explored using the ASTMG119. The introduction of WC-10Co improve the microhardness of the composite coatings, but decrease their corrosion resistance, which are due to the galvanic corrosion of the WC-10Co and HEA. Notably, the results of synergistic effect show that the corrosion of the HW1 coating has an inhibitory effect on wear. The volume loss of tribocorrosion increase with the introduction of WC-10Co, with the HW3 coating experiencing a volume loss of only 46 % compared to that of 3Cr13. The HW1 coating mainly suffers from abrasive wear, surface fatigue wear and adhesive wear. The main wear mechanism of the HW2 and HW3 coatings are abrasive wear, while the fatigue wear is enhanced with the participation of WC-10Co. And the counterbody of the three coatings mainly suffers abrasive wear.

The impact of dual ceramic components (WC/B4C) on the friction performance of copper-based powder metallurgy friction materials and wear mechanism

The copper-based powder metallurgy friction material, modified with dual ceramic components (WC/B4C), underwent friction experiments paired with custom-made carbon ceramic discs. The overall findings are as follows: The judicious addition of dual ceramic components (WC/B4C) can enhance the mechanical, thermal, and frictional performance of copper-based powder metallurgy friction materials. When the WC/B4C ratio is 5:3, the material exhibits the optimal mechanical, thermal, and frictional properties. B4C and WC, after braking, form friction films of B2O3 and WO3. Additionally, the friction film of copper-based powder metallurgy friction materials can be categorized into an oxide layer, a deformation layer, and a matrix layer. The oxide layer primarily consists of Fe2O3, the deformation layer is mainly composed of WO3 and B2O3, and the matrix layer is primarily composed of CuO and Cu2O. With the increase in the WC/B4C ratio, the primary wear mechanisms of copper-based powder metallurgy friction materials shift from abrasive wear to mild fatigue wear, mild fatigue wear progressing to severe fatigue wear, adhesive wear, and fatigue wear, accompanied by a gradual intensification of oxidative wear.

Tailoring microstructure and mechanical properties of U75V steel manufactured by laser direct energy deposition combining cobalt addition with preheating treatment

Laser direct energy deposition (LDED) exhibits great potential for application in rail repairing due to its low cost and high process automation. However, the martensite transformation accompanied by rapid solidification leads to the decrease in the mechanical properties and threatens the service safety. In this study, the reinforcement strategy of combining cobalt (Co) addition with preheating treatment was investigated systematically by combining thermodynamic calculations with experimental characterization to optimize the microstructure and mechanical properties of U75V steel by LDED. The results indicate that cobalt addition can promote the pearlite percentage by facilitating the leftward shift of the continuous cooling transformation (CCT) curve, and refining the interlamellar spacing. But the martensite start (Ms) temperature will also increase from 206.4 °C to 324.1 °C after 7 wt% Co addition. 350 °C preheating treatment on the substrate can also promote the pearlite transformation by elevating the valley temperature of thermal cycling over Ms, as well as the subsequent decrease in cooling rate, but it is not sufficient to prevent martensite formation. A synergistic reinforcement strategy of 7 wt% Co addition and 350 °C preheating was established, which can effectively suppress the occurrence of martensite in the bottom area of deposition layers and expand the pearlite range in the top area. The bonding strength between the substrate and deposition layers has been elevated by ∼20%, accompanied by the increase in elongation and wear resistance. A mixed mode of adhesive and abrasive wear has transformed into a mode dominated by adhesive wear after optimization.

Comparative study on fretting friction and wear characteristics of different impregnated graphite for sealing application

Impregnated graphite has attracted considerable attention and has been widely used as an ideal sealing material in many fields. However, the service environment often contains vibrations, which can easily lead to severe fretting wear and leakage. In this study, the fretting friction and wear properties of resin-impregnated graphite and antimony-impregnated graphite were investigated. The results revealed that only gross slipping regime (GSR) occurred for two impregnated graphite. For resin-impregnated graphite, both abrasive and adhesive wear were discovered. Yet slight fatigue wear occurred on the worn surface of antimony-impregnated graphite at higher cyclic contact stress. The significant properties of the impregnated graphite can be attributed to a transfer film, which uniformly and stably adsorbs on the contact interfaces. This study provides an important basis for matching the industrial applicability of graphite-based modified sealing materials.

Effect of composite processing technique on tribological properties of 3D printed PLA-graphene composites

The present study investigates the effect of processing method on the tribological behavior of 3D-printed Polylactic acid (PLA)/graphene composite samples. Two different methods, electrochemical (EG) and chemical exfoliation (HG) of graphite, are used to prepare graphene fillers. The PLA/graphene composites are processed using two different solvents, chloroform (CHCl3) and dimethylformamide (DMF). Various PLA/graphene composite combinations are prepared by varying filler type, solvent type, and filler loading. The 3D printable composite feedstock filaments are prepared using a single-screw Desktop extruder. Fused Filament Fabrication (FFF) is employed to print samples for tribological tests. The coefficient of friction (COF) and wear rate are evaluated using the ball-on-flat reciprocating sliding wear tests. It was observed that COF was reduced by 76 % with 0.5 wt% loading of filler. The wear mechanism has changed from predominant abrasive wear in neat PLA to adhesive wear for composites. Further, the interactive effect of process parameters is studied using ANOVA. The results indicate that filler type and filler loading significantly influence weight loss. The solvent type has a minimum effect.

Study on the Friction and Wear Properties of Multiple Rare-Earth-Oxide-Reinforced Resin-Based Friction Materials.

Aiming to solve the problem of thermal decay of resin-based friction materials at high temperatures, rare-earth-lanthanum-oxide-/cerium-oxide-reinforced resin-based friction plates were prepared using a hot-pressing molding process. The effect of lanthanum/cerium oxide with different contents on the mechanical and tribological properties of the resin-based friction of materials was studied, and its mechanism was explored. The result shows that lanthanum/cerium oxide improves the mechanical and tribological properties of materials so that the coefficient of friction of the specimen is more stable on adding lanthanum/cerium oxide at 5% and 1%. Lanthanum/cerium oxide improves antidegradation properties of resin-based material and reduces the high-temperature wear rate by enhancing the interfacial effect so that the wear form of the specimen changes from predominantly adhesive wear to predominantly abrasive wear.

Research on Calculation and Optimization Methods for Tooth Flash Temperature and Meshing Power Loss of the Gear System in Drum Shearer

The operating conditions of the drum shearer are very complex, and its ranging arm gear system often suffers from gear scuffing and wear. Gear scuffing is caused by the adhesive wear, which is due to the instantaneous friction and flash temperature of the tooth surface, and the gear meshing power loss is also caused by tooth surface friction. In order to resist tooth scuffing and improve meshing efficiency of the transmission system, an improved semi-analytical tooth surface flash temperature calculation method was used. The tooth flash temperature status under various working conditions were analyzed in detail. Based on the mechanical model of the shearer drum picks, the load condition of the drum was analyzed. Under these load and boundary conditions, the misalignments of each gear pair in the ranging arm were calculated. The tooth surface load distribution was calculated under the gear misalignments, and then the theoretical tooth surface flash temperature and meshing power loss were determined. Next, the tooth micro-geometry was modified to reduce flash temperature and meshing power loss. The flash temperature distribution pattern of the optimized tooth surface was studied under various working conditions, and the meshing power loss was also obtained. Finally, experiments were conducted to verify the effects of the optimized tooth surface on the friction temperature rise and the effectiveness of the modification method. Tooth surface optimization aimed at reducing tooth surface flash temperature can also effectively reduce meshing power loss, which has a significant effect on gear anti-scuffing and energy saving.

Numerical analysis on lubrication failure of main bearings with lemon-shaped bearing shells in high-power diesel engine

The lubrication status of crankshaft main bearings significantly affects the stability and reliability of diesel engine operation. This paper primarily investigates the severe failure of main bearings during developing an industrial high-power 6 V diesel engine and analyzes the causes of bearing failure. Main bearings using lemon-shaped bearing shells exhibited failure after a short period of operation. Based on the multi-body dynamics model, average Reynolds equation, and contact model, a lubrication model for the main bearings was established, and the lubrication characteristics of each main bearing were simulated. The research shows that the abrupt peaks of the lemon-shaped bearing shells on the first and second main bearings are located within the area where the bearings suffer from burst pressure, resulting in additional hydrodynamic pressure and asperity contact pressure on the bearing surfaces. This makes the bearing surface prone to wear and high temperature, which are the primary causes of bearing failure. Under the operating conditions, surface damage of the bearings leads to particle abrasion and high temperature. Subsequently, the lubricating oil gradually deteriorates with the combined action of high temperature and wear particles, causing the main bearings to blacken and adhesive wear.

Microstructure and wear resistance of NiTiNb ternary alloy coatings fabricated in situ by laser cladding

In this study, (NiTi)100-xNbx (x = 5, 10, 15 wt%) ternary alloys with different Nb contents were synthesised in situ by directed energy deposition. Microstructure analysis shows that the (NiTi)100-xNbx ternary alloy possess a typical dendritic structure. With the increase of Nb content, eutectic regions were formed between Nb and NiTi alloy, and TiNb intermetallic compounds were segregated at the eutectic. The NiTiNb ternary alloy formed a good metallurgical bond with the substrate at all different Nb contents, and no cracks or unfused areas were observed. (NiTi)85Nb15 demonstrated excellent elasticity at varying loads, especially at a load of 800 mN, with a modulus of elasticity of only 57.37 GPa. Meanwhile, the in situ synthesised (NiTi)85Nb15 demonstrated excellent wear resistance compared to other materials, with a minimum specific wear rate of 0.96 ∗ 10−4 mm3/Nm. The superelasticity of NiTiNb alloys plays a role in alleviating the effect of normal loads during sliding wear, which is the key to improving wear resistance. The wear mechanism of NiTiNb ternary alloys is dominated by furrowing with a small amount of adhesive wear. This work reveals the influence of Nb element content on the microstructure and wear resistance of NiTi alloys, providing insights into in-situ alloying of NiTiNb ternary alloys through laser cladding. In future research, it is recommended to enhance the functional properties of NiTiNb ternary alloys, such as memory properties or superelasticity by heat treatment.

Effect of Treatment with Microarc Oxidation Technology on Tribological Properties of Nonvalve Metal Low-Carbon Steel.

Steel is one of the most widely used alloys because of its excellent properties such as high toughness, good workability, and low cost. However, steel has weak wear resistance, which limits its range of applications and service life. We have used the microarc oxidation (MAO) technique to form an Al2O3 ceramic coating on the surface of nonvalve metal low-carbon steel, which is used to enhance the wear resistance of low-carbon steel. Tribological experiments have shown that the coefficient of friction is reduced by 26.9%, hardness is improved, and wear resistance is enhanced after MAO compared to the substrate. Through a series of characterizations, the wear mechanism of the MAO samples was found to be a complex friction mechanism including abrasive wear, adhesive wear, and friction oxidation. After MAO, the wear resistance of nonvalve metal low-carbon steel is improved. The use of steel can be extended and its service life can be prolonged. This innovative approach provides a viable solution for the development of low-carbon steel coatings.

Adhesive wear characteristics of mono and hybrid CF/Ep composite with nano-HAP filler

Composites materials with more than two reinforcing materials are called hybrid composites. Tailoring the composites by hybridizing fillers, fibers and matrix will yield better properties compared to mono-composites. Hence, an effort has been made in the current research work to develop carbon fiber epoxy hybrid nanocomposites, comprising different weight percentage of Hydroxyapatite (HAP) to evaluate the potential effects on tribological properties using two body sliding wear method. Taguchi technique (L27 array) has been adopted to investigate the impact of parameters such as filler inclusion (0%, 1.5%, and 3%), load (30, 45, and 60 N), sliding velocity (1, 2, and 3 m·s‒1) and distance (1000, 2000, and 3000 m·s‒1) on wear loss of developed composite. It was observed that the combination of 1.5 wt% HAP composite showed the lowest Ks and the COF. The combination of 1.5 wt% HAP filler, 1 m·s‒1 sliding velocity, 45 N load and 3000 m sliding distance exhibited the lower Ks and COF of 0.44652 × 10‒14 (m3·Nm‒1) and 0.136 respectively. The significance of the parameters was assessed using analysis of variance, revealing that the filler's contribution significantly impacted wear resistance. Developed mathematical model using Regression analysis and the predicted values from K-Nearest Neighbors (KNN) have showed good agreement with experimental values. Micrograph images were captured to analyze the wear mechanisms evident on worn surfaces, revealing failure mechanisms such as extensive matrix damage, fiber exposure resulting from matrix removal, and fiber breakage.

Influence of Si Addition on the Microstructures, Phase Assemblages and Properties in CoCrNi Medium-Entropy Alloy.

The effects of Si addition on the microstructures and properties of CoCrNi medium-entropy alloy (MEA) were systematically investigated. The CrCoNiSix MEA possesses a single face-centered cubic (FCC) phase when x is less than 0.3 and promotes solution strengthening, while the crystal structure shows a transition to the FCC+σ phase structure when x = 0.4 and the volume fraction of the σ phase increases with a microstructure evolution as the Si content increases. The Orowan mechanism from σ precipitation effectively enhances the strength, hardness, and stain hardening of CrCoNiSix MEA, which also exhibits superior hardness at high temperatures. Furthermore, a large amount of σ phase decreases the wear resistance because of the transformation of the main wear mechanism from abrasion wear for σ-free CrCoNiSix MEA to adhesion wear for σ-contained CrCoNiSix MEA. This work contributes to the understanding of the effect of Si addition on FCC structured alloys and provides guidance for the development of novel Si-doped alloys.

Microstructure and properties of multi-layer laser cladding Cu-10Pb-10Sn anti-friction coating

The preliminary experimental results show that the laser cladding technology can produce a well-formed single-layer lead bronze cladding layer with a thickness of 250 μm. The ideal process parameters of the single-layer laser cladding test were selected to study the multi-layer cladding, and the microstructure and properties of the multi-layer cladding were evaluated. The results show that, the multi-layer cladding is composed of α-Cu, Cu41Sn11, Cu5.6 Sn, Pb, and SnO2 phases. There are fine equiaxed crystals at the top of the cladding layer while columnar crystals growing perpendicular to the fusion line at the bottom. The maximum hardness of cladding layer is 248.2 HV near the bottom fusion line. The wear mechanism of multi-layer cladding layer combines abrasive wear and adhesive wear, with wear weight loss and average friction coefficient of 0.0025 g and 0.1161, respectively. The average shear strength between the substrate and the cladding layer is 129 MPa, the shear fracture mode is ductile fracture. Compared with single-layer cladding, the anti-friction performance of multi-layer cladding is significantly improved.

Tribological behavior of PDC-cutter including cemented carbide and polycrystalline diamond composites produced by HPHT for drilling applications

In this study, the tribological behavior of PDC-cutter including WC particles/Ta-20Nb binder composite as substrate and polycrystalline diamond composite as PCD layer produced by high pressure-high temperature (HPHT) for drilling applications was investigated. To examine the metallurgical behavior, phase analysis, hardness of substrate and PCD layer, and tribological behavior, scanning electron microscopy, X-ray diffraction, Vickers microhardness, and wear tests were used, respectively. Due to the HPHT of the manufacturing process, the high hardness of the interfaces, especially for the WC/Ta-20Nb was achieved, which had ∼28% higher hardness than the diamond grits/Ta-20Nb binder. Therefore, no obvious porosity was observed in the interfaces and the composites were completely densified because the particles had good retention strength. The wear results showed that the tribological behavior of PCD layer/granite or marble pairs was directly influenced by the binder content, with samples having a lower binder content showing superior wear performance. Additionally, worn surface investigations demonstrated that adhesive and abrasive wear mechanisms were present in all pairs, with their intensities being strongly correlated with the binder concentration.

High-performance liquid metal-based SiC/Graphene-Mo hybrid nanofluid for hydraulic transmission

A novel liquid metal-based SiC/Graphene-Mo hybrid nanofluid (LMNF) has been fabricated. The nanoparticles are uniformly dispersed, and LMNF temperature-viscosity characteristics is stabler in a wider temperature range than traditional hydraulic media. With this, the LMNF tribological performance on Al2O3 and SS316L friction pairs is studied: The LMNF has superior severe-pressure and high-temperature lubrication with the nanoparticle-enabled wear resistance. The SS316L surface forms composite nanofilm with the LMNF, which prevents adhesive wear and mitigates liquid metal corrosion. Comparatively, the nanoparticles function as "micro-bearings" on the Al2O3 surfaces to assist lubrication. These benefits are reflected in the gear pump volumetric efficiency and wear rate of our industry-level hydraulic system, approving LMNF as a potential hydraulic transmission medium in harsh conditions.

Influence mechanism of grinding surface quality of 20CrMnTi steel on contact failure

To reveal the influence mechanism of the grinding surface quality of 20CrMnTi steel components on the tribological characteristics and contact fatigue performance, accelerated tests for sliding friction wear and fatigue damage were carried out. Tribological characteristics and contact fatigue performance get worse with increasing surface roughness while getting better with increasing surface microhardness. Residual compressive stress is conducive to inhibiting the initiation and propagation of cracks and promoting contact fatigue performance. Additionally, mechanical friction, abrasive wear, adhesive wear and fatigue damage coexist and form a competing failure mechanism under the synergistic effect of frictional wear and contact fatigue failure. The damage process mainly manifests as wear, stress concentration induced fatigue, microcracks, pitting, and spalling in the shallow layer. This study is more beneficial to promote the 20CrMnTi steel transmission parts manufacturing products for high precision, low damage, and long life.

Microstructure and tribological properties of laser cladded TiC reinforced WC-10Co4Cr coatings at 500 °C

WC-10Co4Cr-xTiC coatings were fabricated on H13 steel by laser cladding to improve their wear resistance. The effects of TiC mass fraction on the friction-wear properties at 500 °C were investigated using a high-temperature wear tester, and the wear mechanism was discussed in detail. The results show that the WC-10Co4Cr-xTiC coatings are composed of WC, W2C, Co3W3C, Cr7C3, and TiC phases, and the porosity is reduced by the addition of TiC. The average coefficients of friction of WC-10Co4Cr-xTiC coatings are increased with the TiC mass fraction; while the wear rates are opposite, showing that the addition of TiC plays a key role in wear resistance. Moreover, the wear mechanism of WC-10Co4Cr-xTiC coatings is primary abrasive wear, slight adhesive wear, and oxidative wear.