Wear Experiments Research Articles

Theoretical Calculations and Experimental Study of the Nitrided Layer of 1Cr17Ni2 Steel

Due to the harsh operating conditions experienced by 1Cr17Ni2 steel, efforts were made to optimize its performance by subjecting 1Cr17Ni2 stainless steel to nitriding treatments at temperatures of 460 °C, 500 °C, and 550 °C, each for durations of 8 and 16 h. The formation state of its cross section was observed through a metallurgical microscope and scanning electron microscope, and it was characterized by hardness measurement. Through a ball-on-disk wear experiment, the adhesive wear and friction coefficient of its non-lubricated sliding were measured. The phase composition of its surface was measured by XRD. The results revealed that nitriding led to the formation of a modified layer on the surface of the samples, with a depth of 130 μm after nitriding at 550 °C for 16 h. The hardness of the modified layer exceeded that of the matrix, reaching up to 1400 Hv0.1. X-ray diffraction (XRD) analysis of the sample surfaces indicated the presence of high-hardness phases such as CrN, γ′-Fe4N, and ε-Fe2-3N. This article predicts the mechanical properties of nitrided phases in high-alloy martensitic stainless steel through first-principles computational methods. We provide a reference for improving the performance of high-alloy steel after nitriding through a combination of theoretical calculations and experiments.

Thermal and Mechanical Mechanisms of Polymer Wear at the Nanoscale.

Wear is a ubiquitous phenomenon that limits the life of many engineered components with sliding interfaces through the gradual removal of material. The wear of polymers is crucial in many applications, ranging from bearings to orthopedic implants to nanolithography processes. The wear rate of polymers is strongly affected by the stress and temperature at the interface. The effects of temperature and stress are often described empirically since the wear process involves complex interactions between multiple asperities on rough surfaces over a range of length scales. Nanoscale tribology experiments at the single-asperity level have provided new insights into the underlying mechanisms of wear. Experiments on hard covalently bonded materials, including silicon and diamond, have demonstrated that wear is an atomic attrition wear process that can be modeled using stress-assisted transition state theory. Here, we examine the wear of a common polymer, polymethylmethacrylate (PMMA), at the nanoscale as a function of stress and temperature and show that the polymer wear is controlled by a combination of atomic attrition and viscoelastic relaxation. While the wear experiments are conducted at the nanoscale via atomic force microscopy, the results show that accounting for the local stress distribution at the contact interface is critical to understanding the wear behavior, an effect that was not considered in earlier studies on hard materials. Using a model that accounts for the stress distribution, we demonstrate the ability to predict the wear volume within 8%.

A biomimetic micro-texture based on shark surface for tool wear reduction and wettability change

Aiming at the problems of severe tool wear and difficulty in ensuring machining surface quality during the cutting process of Ni-base superalloy, a micro-texture design method resembling a shark surface is proposed, which simplifies the skin teeth on the shark surface into a diamond shaped structure with ribs. Different micro-textured samples were prepared using femtosecond laser, and surface wettability characterization and friction and wear experiments were conducted to study the wear reduction and anti wear effects of micro-texture. The parameter combinations with the maximum contact angle and the minimum coefficient of friction were selected. The wear mechanism of YG8 carbide alloy and GH4742, as well as the wear reduction mechanism of microstructure were revealed. Biomimetic cutting tools were prepared and their effectiveness in controlling tool wear, reducing cutting forces, and improving machining quality was verified through milling experiments.

Molecular simulations of amine-based organic additives at a steel surface: Effect of the internal molecular structure on adsorption

Lubricating oils mitigate wear in gears and rolling bearings lengthening the lifespan of drivetrain units for electric vehicles. Amine-based organic additives from the lubricating oil contribute to alleviating wear by adsorbing on rubbing steel surfaces of mechanical contacts and forming anti-wear films. Cross-pin wear experiments suggest that additives with branches in polar heads improve wear protection, while remaining environmentally friendly. Experiments show a reasonable correlation with the energy of adsorption calculated from molecular dynamics simulations at large surface coverages. Whereas adsorption strengths and surface coverages are barely affected by the conformation of alkyl chains (cis/trans), they are affected by the length of branches in polar heads of additives. Results suggest better performances for branch lengths containing 3–4 C atoms.

TRIBOLOGICAL INVESTIGATION OF TUNGSTEN CARBIDE AND HARD CHROME COATINGS ON EN19 FOR COLD ROLLING APPLICATION

In the heavy sheet metal industry, rolls are generally made up of EN19. To enhance the life of the cold rolling mills it can be coated. This paper presents an experimental study to check the effect of alloy coatings such as Hard Chrome and Tungsten carbide on wear resistance and other characteristics of roller base materials EN19 which is used in rolling process of heavy metal industry. In this paper a comparative tribological study of Hard Chrome, Tungsten carbide, EN19 through hardness testing, surface roughness analysis, SEM, and EDS, XRD, sliding wear experiments and statistical study through Design of Experiment has been performed to find out the best material which can increase the life of rolls. From the experiments carried out it has been found that hardchrome has 15.19 times the longevity of the substrate EN19. Tungsten carbide has 19 times the life of EN19 and 1.25 times the life of hardchrome. Tungsten carbide coating gives more hardness and wear resistance than the Hard Chrome and EN19 base material of the roll. Thus, using Tungsten carbide coating on EN19 rolls will improve the life and enhance the longevity of the roll used in cold rolling process in heavy steel industry.

Effect of Shot‐Peening Process and Nanoparticle‐Added Lubricant on the Tribological Performance of Aluminium‐Based Sliding Bearing Material

ABSTRACTIn this study, it is aimed to increase the wear and fatigue performance of aluminium‐based sliding bearing material by using silver nanoparticles (AgNPs) added lubricant and shot‐peening process. The main purpose is to minimise the wear of the bearing material by penetrating AgNPs added lubricants into the rough surfaces formed by shot peening. Almen intensity, coverage and shot size parameters in the shot‐peening process were analysed in terms of hardness, surface roughness and fatigue strength. The shot‐peened aluminium bronze was subjected to wear experiments under dry, pure water and AgNPs added lubricant conditions. The wear test results were analysed in terms of friction coefficient, wear volume and surface roughness parameters, and the interaction of lubricant and shot‐peening parameters was evaluated. According to the results of the shot‐peening experiments, the Almen intensity was the most effective parameter in terms of hardness and surface roughness (91.62%). It was concluded that the hardness value was 8% higher at high Almen (12–14A) intensity compared with low Almen intensities, and the shot‐peening process could increase the fatigue strength by ~21 times. According to the wear tests, the most effective parameters were 4–6 Almen intensity and AgNP‐added lubricant.

Effect of groove textures on wear of friction pair between groove side and scraper under different factor combinations

Three-body wear is the primary wear mechanism in friction pair between groove side and scraper. This study quantitatively investigates the effect of groove textures on three-body wear under different factor combinations through abrasive wear experiments. The results indicate that groove textures significantly reduce wear of samples. The wear reduction rate of sample reaches 41% under the optimal factor combination. Width, depth, and tilt angle of groove textures significantly influence wear loss. Among these factors, width exhibits a negative effect on the change of wear loss, while depth and tilt angle show positive effects. Additionally, there are interactive effects on the change of wear loss between width and depth, as well as width and tilt angle. The effect process of groove textures to three-body wear was qualitatively analyzed by discrete element method (DEM) simulation. Combined with wear morphologies, the wear-resistant mechanism of groove textures was explored. The results indicate that groove textures can mitigate the severity of three-body abrasive wear, reduce the contact area between particles and samples, alter particles movement and enhance wear resistance. Meanwhile, groove textures can serve as a guiding mechanism to modify particles movement and direction and transform the sliding motion of coal particles into rolling motion, converting the continuous “face-face” contact of three-body wear into intermittent “point-face” and “line-face” contacts. This study provides novel study ideas and theoretical foundations for wear-resistant designs in mining machinery and three-body wear equipment.

Improving the cavitation corrosion resistance of 6061 aluminum alloy by anodizing

Anodic oxidation is a common surface strengthening method to improve the comprehensive properties of aluminium alloys (AAs), such as wear and corrosion resistance, but its application on cavitation erosion is rarely touched. In this paper, the effect of sealing treatment on the properties of anodized AA6061 was investigated by using scanning electron microscopy (SEM), friction and wear experiment, cavitation experiment, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The experiment results showed that the oxide film under hydrothermal sealing had a superior cavitation and corrosion resistance, due to the high hardness and less defects in the film. Compared to distilled water conditions, corrosion mitigated the cavitation erosion of anodized AA6061 in simulated seawater, and the weight loss under simulated seawater after sealing was reduced up to a maximum of 30%.

A comprehensive sliding wear prediction method for planetary roller screw mechanism

The thread-pairs wear has a significant role in the transmission accuracy, operational stability and service life of planetary roller screw mechanism (PRSM). Nevertheless, the previous literatures still lack the investigation on the wear evolution of roller, nut and screw. Hence, an accumulative wear depth (AWD) prediction model is proposed for PRSM with reciprocating motion. The presented model is validated by the measured wear phenomena of thread pairs and the experimental results in the literature. The equivalent sliding wear experiment of PRSM is designed and the sliding wear coefficient of PRSM material is obtained by the equivalent sliding wear experiment. Considering the thread profile error caused by AWD of roller, nut and screw, the load distribution (LD) and sliding velocities on screw-roller (SR) and nut-roller (NR) sides are calculated. More importantly, the interactions between the AWD, LD and sliding velocity are investigated. Furthermore, the effects of axial load on the AWD, sliding velocities in contact regions and load distribution coefficient are analyzed.

EFFECT OF TiC ADDITION ON MICROSTRUCTURE AND PROPERTIES OF LASER CLADDING AlCoCrFeNi2.1 COATINGS ON H13 STEEL

[Formula: see text][Formula: see text][Formula: see text][Formula: see text]xwt.%TiC ([Formula: see text], 6, 9) coatings were prepared on H13 steel by laser cladding (LC) technology. It was characterized by a friction and wear test machine, optical microscope (OM), X-ray diffractometer (XRD), hardness tester, etc. The effects of different TiC contents on the microstructure and properties of [Formula: see text] coatings were analyzed. The results show that the coating microstructure without TiC addition is dominated by coarse columnar crystals and dendrites. After the addition of TiC, the coated massive crystals and equiaxed crystals become finer. XRD analysis reveals that the phase structure of the coating has FCC, B2 solid solution phase and TiC-reinforced phase. TiC phase can significantly improve the hardness of the coating. The microstructure reveals that fine TiC particles are widely distributed among the dendrites of the FCC matrix. The hardness and friction wear experiments revealed that the average hardness of the coatings with TiC has increased significantly compared to that of the substrate. The hardness of the [Formula: see text] with 9%TiC coating increased by 184.6% compared to that of the substrate. The friction coefficient was the smallest at 0.748. The lowest self-corrosion current was [Formula: see text][Formula: see text][Formula: see text]. The [Formula: see text] with 9%TiC coating had the best corrosion resistance.

Effect of alternating magnetic field on microstructure and mechanical properties of Ni60/La2O3 laser cladding layer

A Ni60 cladding layer containing 1.6 wt% La2O3 was prepared on 35CrMoV steel using an alternating magnetic field-assisted laser cladding technique. The microstructure, phase composition, microhardness, and tribological properties of the composite coatings were characterized. Based on experimental results, the main components of the 1.6 % Ni60 + La2O3 cladding layer are γ-(Fe,Ni), Cr23C6, FeNiSi, Ni3B, Ni4B3 and Cr2B. The EBSD analysis reveals that the increase in intensity of the alternating magnetic field leads to a significant refinement in the average grain size of the cladding layer, thereby greatly enhancing microstructural uniformity. The average grain sizes of the layers with 0–15 mT magnetic field intensity are 28.515 μm, 26.076 μm, 23.878 μm and 18.337 μm, respectively. The TEM bright field images reveal that the enhancement of magnetic field intensity facilitates the precipitation of γ′ within the cladding layer. Friction and wear experiments demonstrated that a Ni60 composite coating containing 1.6 % La2O3 exhibited superior friction and wear performance at a magnetic field intensity of 15 mT due to its highest average hardness (608.97 HV1), lowest friction coefficient (0.394), and excellent wear morphology.

Comprehensive analysis of the effect of structural parameters on erosion wear, structural stress, and deformation of high-pressure double-elbow in shale-gas fracturing

In field hydraulic fracturing operation of shale gas development, the high pressure and large displacement liquid-particle two-phase fracturing fluid can be forced to change direction many times through high-pressure double-elbow, and be transported from the outlet pipeline of the fracturing pump to the main pipeline. The high-pressure double-elbow is prone to be affected by erosion wear and Fluid-Structure Interaction (FSI), resulting in perforation and fracture, posing a potential safety threat to field operation. In this study, we conducted the erosion wear experiments on 35CrMo steel used for high-pressure double-elbow in shale-gas fracturing. The erosion rates under different impact angles and flow velocities were obtained, and proposed a novel model of erosion prediction for high-pressure double-elbow. Then the numerical investigation was employed to conduct a comprehensive analysis of erosion wear, structural stress and deformation by the coupling of Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA). The effects of structural parameters such as connection straight pipe length, pipe inner diameter and fluid turning direction were discussed. The results indicate that with the increase of connection straight pipe length, the flow erosion decreases first then varies little, and the deformation gradually increases. Slight erosion wear but large structural stress and deformation in major inner diameter pipe. And the minimum degree of erosion and flow-induced deformation present with the fluid turning direction of double-elbow as 0°. The study can provide references for the design, installation and detection of high-pressure double-elbow and ensure safety in the process of shale gas fracturing.

Experimental investigations and finite element simulation for predicting wear life of overrunning clutches

An overrunning clutch, generally known as a freewheel clutch, is a direction dependent torque transmitting device that works on the principle of wedge friction. The overrunning wear characteristics of freewheels are studied using pin-on-disc tribometry. The wear experiments for freewheels are performed at accelerated loads to promote wear in a short period. The overrunning wear life of the clutch under operating conditions is predicted using an appropriate load-life relationship. A finite element-based Archard’s wear model is implemented as a numerical strategy to evaluate the wear profile. The maximum local wear for various loads is computed using experimentally obtained wear and friction coefficients. The numerical simulation is performed with an adaptive mesh technique utilizing incremental nodal displacements to predict surface wear. The experimental and numerical results are compared in terms of wear characteristics. The numerical wear results are almost 11% higher than the experimental results. The wear life of an overrunning clutch is predicted in terms of overrunning speed based on the wear amount.

Research on erosion wear behavior of NiTi alloy coating fabricated via high-frequency induction heating technology

NiTi alloy is widely used in extreme working conditions due to its pseudoelasticity, shape memory effect and wear resistance. In this study, the NiTi alloy coating (Ni49.8Ti50.2 (at%)) was fabricated by high-frequency induction heating. The coating was well-formed on the surface of cemented carbide YG8 and converted to crystalline after aging treatment. The results of 70h erosion wear experiments carried on the rotary erosion wear test device showing that the erosion wear amount of the coating was reduced by 93 % compared with that of YG8, resulting from the deformation recovery effect. Moreover, the main erosion wear mechanism of the coating was micro-cutting and ploughing. This study can provide technical support and theoretical basis for preparing of NiTi alloy coating and erosion wear resistance.

Damage Mechanism Analysis of the Connecting Screw of Turbine Disk-Drum Assembly

The turbine disk-drum is one of the key components of an aero-engine and its assembly is connected with high-strength refined screws. But due to the uncoordinated rotation and deformation, the screws have abnormal wear damage. Through detailed contact stress analysis of screw body and component level using the finite element method, combined with experimental observation, the mechanism of wear damage of screw surface in screws is determined. It mainly includes the following: Firstly, the finite element method is used to calculate the deformation and stress distribution of the connecting screw of the turbine disk-drum assembly. Then, after the overspeed test, the morphology of the screws disassembled from the disk-drum assembly is evaluated. It was found that the wear degree in the circumferential direction and axial direction of the screw was quite different, that is, the screw wear experiment was consistent with the finite element analysis results. Finally, the influence of different rotation states and screw tightening states on screw wear was compared and analyzed. Conclusions obtained in this paper will be helpful to improve the assembly reliability of turbine drum.

Response Surface Methodology Optimization of Wear Rate Parameters in Metallic Alloys

The optimization of wear rate parameters in metallic alloys using Response Surface Methodology (RSM) has been experimentally performed. The wear rate, a critical factor affecting the durability and performance of metallic components, served as the response parameter, while track diameter, sliding speed, and mass difference were considered as independent variables. The Central Composite Design (CCD) experimental method systematically explored the response surface and optimizes the wear rate. A mathematical model was developed, revealing a significant p-value of 0.043 in the ANOVA table, indicating the collective influence of the independent variables on wear rate at a significance level of 0.05. Furthermore, the model demonstrates a substantial explanatory power, with R-squared of 69.45% and adjusted R-squared of 51.95%. The p-value calculated to be 0.60 for the statistical Lack of fit indicated a satisfactory model. These findings highlight the effectiveness of RSM in optimizing the experimental input values and offer valuable insights for enhancing the durability and performance of metallic alloys in various industrial applications. The obtained result addresses the problem of uncertainty inherent in optimal levels of input parameters wear experimentation.

Study of the Effects on the Strengthening Mechanism and Wear Behavior of Wear-Resistant Steel of Temperature Controlling in Heat Treatment.

To improve the wear resistance of the materials used for blades in engineering machinery, this study focused on the microstructural characteristics, mechanical properties, and wear behavior of HB500 grade wear-resistant steel developed using an optimized heat treatment system. To improve the temperature uniformity of the heat treatment furnace, the method of cyclic heating was used to heat the components. Carefully designing the quenching equipment, such as using a cross-shaped press, was employed to enhance the quenching effect and reduce the deformation of the steel plates. The crystal orientation analysis revealed a uniform and fine-grained microstructure, primarily characterized by plate-type tempered martensite, which indicated a good hardenability. The microstructure observations showed that the width of martensite is approximately 200 nm, with a significant presence of dislocations and carbides. Tensile tests and multi-temperature gradient impact tests indicated superior mechanical properties compared to similar grade wear-resistant steels, including a Rockwell hardness of 53, tensile strength of 1610 MPa, yield strength of 1404 MPa, and total elongation around 12.7%. The results of friction and wear experiments indicate that the wear rate decreases as the load increases from 100 N to 300 N, demonstrating an excellent wear resistance under a large load. Observations of the worn surfaces indicated that the wear mainly involved adhesive wear, fatigue wear, and oxidative wear. The properties' improvements were attributed to microstructure refinement and precipitation strengthening. This study indicates that designing a heat treatment system to control temperature uniformity and stability is feasible.

The influences of normal load and displacement amplitude on fretting wear behavior of M50 bearing steel

This study aims to obtain key parameters such as the fretting wear coefficient and wear rate of M50 bearing steel through fretting wear experiments. By integrating the Umeshmotion subroutine, a validated 3D ball-plane energy dissipation fretting wear model was established. The research explores wear behavior and transition mechanisms under different normal loads and displacement amplitudes. Experimental and finite element analyses show that fretting wear rate is negatively correlated with normal load and positively correlated with displacement amplitude. These variables influence contact stress, shear stress, and slip distance, affecting wear morphology. Results indicate that increasing normal load transitions fretting wear from gross slip to partial slip, while increasing displacement amplitude shifts it from partial slip to gross slip.

Study on the Wear Behaviour of Aluminium foam Reinforced Glass Fibre Epoxy Composites

Hand layup was used to fabricate the glass fibre reinforced aluminium foam epoxy composites in this study. On the manufactured materials, dry sliding wear experiments were performed. The effect of wearprocess parameters such asapplying load (kg), speed (m/s), and sliding distance (m) on specific wear rate (Ws) was investigatedand the obtained results were compared with neat glass fibre reinforced epoxy composite in this work. The outcome of these results showed that specific wear rate (Ws) of glassfibre epoxy composite containing aluminium foam decreased as compared with neat glass fibre reinforced polymer composites. Experimental results showed that a minimum wear rate of 10.1 �m was attained for the sliding velocity (1.5 m/s), Applied load (2 kg), and sliding distance (1000 m) in the fabricated composite laminates. It was observed thatthe resistance to wear in glass fibre reinforced aluminium foam composite was mainly due to the bond strength between aluminium foam and epoxy.

Effect of deposition pressure on friction and wear properties of BWS2 composite coatings

This study investigated the impact of deposition pressure on the microstructure and tribological properties of B/WS2 composite coatings deposited via unbalanced magnetron sputtering. Deposition pressures of 0.6 Pa, 0.8 Pa, 1.0 Pa, 1.2 Pa, and 1.4 Pa were used during the deposition process. The microstructure and mechanical properties of the B/WS2 composite coatings were characterized, and friction and wear experiments were conducted. The study found that the microhardness of the B/WS2 composite coatings decreased as the deposition pressure increased. The highest hardness of the coating, reaching 8.1GPa, was observed at a deposition pressure of 0.6 Pa. This was due to the formation of Tungsten tetraborate (WB4) during the deposition process, which had a high hardness and improved the mechanical properties of the coating. The wear life of the B/WS2 composite coatings was at its best, reaching 9.9 × 104 cycles, and the friction coefficient was at its lowest when the deposition pressure was 1.2 Pa. Selecting an appropriate deposition pressure can improve the tribological properties of B/WS2 composite coatings. Doping Boron can improve the hardness and wear resistance of the composite coatings. Abrasive wear and spalling are the two main wear forms of B/WS2 composite coatings.