Wear Damage Research Articles

Surface Design of 3D-printed Polyether Ether Ketone for Abrasive Wear Resistance

The surface features of additively manufactured polymer parts differ compared to extruded polymer parts and decide their performance in terms of power transmission applications. Layer thickness is one of the important process parameters chosen based on the part complexity and production speed, influencing the surface features. The abrasive wear performance of high-performance polyether ether ketone (PEEK), which determines the performance of power transmission elements such as bearings and gears, is reported in this article. The layer thickness employed in fabrication, which varies from 0.1 mm to 0.35 mm, influences the surface roughness, real contact area, and hardness of the as-printed PEEK. The friction coefficient and wear resistance of a printed part are influenced by the layer thickness employed, indicating the need for a proper choice of layer thickness for power transmission applications. Samples printed with a layer height of 0.25 mm and higher exhibited an increase of friction coefficient and wear loss due to the weak surface integrity. The friction and wear characteristics of additive manufactured samples are compared with extruded samples. Wear debris accommodation in the grooves of the as-printed surfaces accelerates the wear due to three-body abrasion in high layer thickness samples. The micromechanisms of wear damage in different layer thickness samples are discussed. The observations indicate the strong influence of layer thickness and facilitate the selection of appropriate layer thickness for the required friction coefficient in a particular application.

Tribological properties of Al-GNP composites at elevated temperature

Lighter and more powerful next generation vehicles and other rotary machinery demand bearings to operate in harsher conditions for higher efficiency, and the continuous development of advanced low-wear and friction materials is thus becoming even more important to meet these requirements. New aluminium composites reinforced with high performance lubricate phases such as graphene nanoplatelets (GNPs) are very promising and have been vigorously investigated. By maintaining a low coefficient of friction (COF) and offering great strength against wear due to their self-lubricating capability, the solid lubricant like GNPs protect the bearing surface from wear damage and prevent change in metallurgical properties during temperature fluctuations. This paper first studies the high-temperature tribological performance of aluminium matrix composites reinforced with GNP, consolidated via powder metallurgy, then elucidates their tribological mechanism. We report that the best tribological performance is achieved by the composite containing 2.0 wt% GNP, with an extraordinarily low COF of 0.09 and a specific wear rate of 3.5×10−2 mm3·N−1·m−1, which represent 75% and 40% reduction respectively, against the plain aluminium consolidated under identical conditions. The in-track and out-of-track Raman analysis have confirmed the role of GNPs in creating a tribofilm on the counterpart surface which contributed to the excellent performance.

Analytical modeling of particle size effect on impact wear deformation characteristics of ductile materials

AbstractThis study aims to analytically predict the material impact wear rate and improve the prediction accuracy and applicability of existing impact wear prediction models. The ABAQUS software was used to numerically model and analyze the erosion pit morphology and stress distribution characteristics. Micromorphological testing was used to investigate the impact wear damage mechanism, and an improved impact wear prediction model was developed by introducing the particle size. The results show that the maximum von Mises stress in the impact area of the target material can reflect the severity of the damage to the target material. The peak stress varies with the impact angle. The target material significantly absorbs the energy of small particles at higher impact angles and large particles at vertical impacts. The depth of the hardened layer resulting from particle impact increases from 3 to 10 μm with increasing impact angle. When the impact angle is unchanged, the depth of the hardened layer increases by 3% to 5% with an increase in particle size. The hardened layer limits further plastic deformation of the metal material. Comparing the analysis results with the experimental results reveals that the proposed formula that uses the size factor can predict the volume loss of plastic metallic materials with different particle sizes, impact angles, and impact velocities more accurately.

Feature Extraction of a Planetary Gearbox Based on the KPCA Dual-Kernel Function Optimized by the Swarm Intelligent Fusion Algorithm

The feature extraction problem of coupled vibration signals with multiple fault modes of planetary gears has not been solved effectively. At present, kernel principal component analysis (KPCA) is usually used to solve nonlinear feature extraction problems, but the kernel function selection and its blind parameter setting greatly affect the performance of the algorithm. For the optimization of the kernel parameters, it is very urgent to study the theoretical modeling to improve the performance of kernel principal component analysis. Aiming at the deficiency of kernel principal component analysis using the single-kernel function for the nonlinear mapping of feature extraction, a dual-kernel function based on the flexible linear combination of a radial basis kernel function and polynomial kernel function is proposed. In order to increase the scientificity of setting the kernel parameters and the flexible weight coefficient, a mathematical model for dual-kernel parameter optimization was constructed based on a Fisher criterion discriminant analysis. In addition, this paper puts forward a swarm intelligent fusion algorithm to increase this method’s advantages for optimization problems, involving the shuffled frog leaping algorithm combined with particle swarm optimization (SFLA-PSO). The new fusion algorithm was applied to optimize the kernel parameters to improve the performance of KPCA nonlinear mapping. The optimized dual-kernel function KPCA (DKKPCA) was applied to the feature extraction of planetary gear wear damage, and had a good identification effect on the fuzzy damage boundary of the planetary gearbox. The conclusion is that the DKKPCA optimized by the SFLA-PSO swarm intelligent fusion algorithm not only effectively improves the performance of feature extraction, but also enables the adaptive selection of parameters for the dual-kernel function and the adjustment of weights for the basic kernel function through a certain degree of optimization; so, this method has great potential for practical use.

Development of Risk-Based Approaches to Determining the Damageability and Useful Life of Railway Transportation Assets

Modern problems of railway transport in Russia, such as the general technical condition of transportation assets, and relevant issues of their safe operation, substitution of imported equipment and its components, implementation of the programs of technological development give rise to the need to create new equipment and technologies, constructing schemes for long-term development of transport based on new safety requirements and strategic planning. Current level of developments does not allow to completely eliminate damage, failures and accidents regarding railway transportation assets manufactured in accordance with the current regulatory framework. Solving these problems is possible by identifying the actual state of an object regarding cyclic, corrosion, wear and other damage accumulated during operation, which determines the onset of limit states of the basic elements of an asset, taking into account resource recovery technologies at various stages of the life cycle, both in standard (design) operating conditions and beyond them.The article refers to the problems associated with ensuring safe operation of railway transport, with the aim of substantiating based on existing regulatory and technical documents of new approaches to the analysis of damageability, vulnerability of objects and assessment of the risks of accidents and disasters. The development of interaction through a system of new problem statements and regulatory and technical documents, as well as more active involvement in the use and development of the fundamental laws of physics, chemistry, and mechanics of real-life processes in the environment, make it possible to implement new concepts, strategies, and developments of advanced research for technical objects with the use of digital and intelligent technologies.

Research on Wear Damage of Anchor Chain under Different Load Modes

In the marine environment, mooring anchor chains bear complex loads such as axial tension and out of plane bending. These loads cause wear and corrosion damage to the anchor chain, reducing its fatigue strength, and even leading to fatigue fracture. The inspection load applied to the anchor chain before leaving the factory will generate residual stress, which will affect the stress characteristics and fatigue life of the anchor chain during service. This article aims to obtain the residual stress generated by the test load on the anchor chain through numerical simulation, and explore the impact of the test load residual stress on the stress characteristics and wear performance of the anchor chain; Analyze the stress and contact characteristics of anchor chains under different bending angles and wear depths, and obtain the locations where fatigue damage is prone to occur in the later stage of anchor chain wear.

Microstructures and properties of FeCrAlMoSix high entropy alloy coatings prepared by laser cladding on a titanium alloy substrate

By laser cladding, a FeCrAlMoSix high entropy alloy (HEA) coating (x = 0, 0.05, and 0.10) was produced on Ti6Al4V titanium alloy surface to improve its resistance to the influence of high-temperature fretting wear on Ti6Al4V. The mechanical characteristics, phase composition, and fretting wear resistance of the coating were examined at RT and 400 °C. The findings show that the FeCrAlMoSix coating is made up of a B2 phase and an intermetallic compound μ phase. At RT and 400 °C, increasing the Si concentration significantly enhanced the coating's microhardness. At x = 0.10, the average microhardness of the coated surface was 805 HV, and grain refinement and increase in μ phase were the reasons for the improvement of microhardness. The fretting wear experiment shows that the coating system can reduce wear loss and COF. In addition, at RT and high temperature, increasing the Si element can considerably improve the coating's resistance to fretting wear. However, due to stress concentration, too much μ phase may increase the risk of microcracking in the coating. This work provides a potential method for improving the protection against fretting wear damage on the titanium alloys' surface.

Analysis of rolling contact fatigue and wear characteristics of aging-treated laminar plasma strip quenching rails

The application of laminar plasma discrete quenching (LPQ) technology to enhance the wear resistance of railway tracks has been a notable advancement. Nonetheless, it has been observed that LPQ-treated rails experience a reduction in rolling contact fatigue (RCF) resistance. Our previous study found that aging treatment can improve the toughness of laminar plasma spot quenched rails. However, the microstructure as well as the mechanical properties of strip quenching are significantly different from those of spot quenching. To tackle this concern, the study delves into the wear and RCF damage mechanisms of aging-treated laminar plasma strip quenching (ALPQ) rails. The findings reveal that the aging process induces the precipitation of supersaturated solid solutions within the hardened layer, consequently elevating the RCF resistance of ALPQ rails. Following appropriate aging treatment, nearly complete elimination of fatigue cracks on the rail surface is achieved.

Effects of Heat Treatment and Erosion Particle Size on Erosion Resistance of a Hypereutectic High-Chromium Cast Iron

This research addresses the erosive resistance of a hypereutectic high-chromium cast iron subjected to solid particle erosion. The study stems from a specific application of high-chromium cast iron, i.e., the critical surfaces of large industrial fans operating in a cement clinker grinding plant where such damage is a limiting factor for the components’ lifespan. A dedicated experimental investigation on the impact of substrate microstructure and erodent particle size on erosion resistance was set. The experimental campaign, conducted on a dedicated test bench per the ASTM G76 standard, comprised the analysis of the as-received, tempered, and destabilized conditions for the cast iron. From a preliminary image analysis of the microstructural features, two diameters of the erodent powder for the erosion tests were defined. The observed erosion rate decreased with the increase in the mean particle diameter of the erodent, indicating more severe erosive conditions for smaller particles. From the analysis of the worn surfaces, it was possible to highlight the involved mechanisms concerning the considered test combinations. For the as-received condition, the erosion rate with the larger mean particle diameter of the erodent decreased three times compared to the smaller one. For the heat-treated conditions, the erosion rate was halved with the larger mean particle diameter of the erodent. The proposed analysis, intended to acquire more insight into the limiting factor for the components’ lifespan for erosive wear damage, proved that erosion resistance is not dependent on the material’s hardness. The contribution of the mean particle diameter of the erodent is predominant compared to the substrate conditions.

Assessment of performance properties of compressor blades made of EI961-Sh steel with nickel-cadmium and titanium-nitride coatings

Comparative tests of compressor blades made of EI961-SH steel were carried out for resistance to fatigue, abrasive wear and corrosion damage to the surface when applying electrolytic nickel-cadmium and vacuum plasma coating of titanium nitride.

Design and Control for High-Reliability Power Electronics: State-of-the-Art and Future Trends

Electrification is a mega-trend in the modern economy, urged by the need for a more ecological and sustainable impact of new technologies, among many other merits related to the process of electrification. The widespread adoption of renewable energy, transportation electrification, energy storage systems and smart manufacturing is remarkable. As a result, power electronics has become the critical enabling technology for improving energy efficiency and sustainability. In recent years, the reliability of power electronic equipment has been under scrutiny, especially in mission-critical applications of power electronics converters. Recently, special attention has been paid to the development of lifetime models of the main electronic components, which could then be applied to probabilistic analysis based on the mission profile of system-level reliability. This prediction methodology has some limitations because it does not consider external factors and agents other than the wear itself. Redundancy has been the typical approach to improve the availability of mission critical power electronic systems, which could be associated with considerable extra cost. Fault-tolerant converters were proposed as a more cost-effective alternative solution that could also extend the service life. The maintenance cost could be reduced by using active thermal control, which allows the balancing of wear damage in modular power electronic converters and, consequently, the scheduling of maintenance events. A further step could be taken with the application of real-time condition monitoring of systems, which has evolved into the concepts of predictive and prescriptive maintenance that allows for prediction and mitigation of faults. These techniques are under active development and are expected to benefit from new methods and technologies from rapidly progressing areas of artificial intelligence and digital twin. This paper provides a detailed overview on the recent trends and advances in the field of high-reliability power electronics systems.

Microstructural effects on impact-sliding wear mechanisms in D2 steels: The roles of matrix hardness and carbide characteristics

This study investigates the wear micromechanisms of D2 steels under impact-sliding conditions, offering insights into their performance when used in applications such as trimming dies for high-strength steel sheets where they undergo plastic deformation and chipping. Two D2 steel samples, both with a bulk hardness of 59.7 HRC but different matrix hardnesses and carbide distributions, are tested by using an impact-sliding wear test rig at Hertzian contact pressures exceeding 2 GPa. The sample with a softer matrix exhibits wear primarily through delamination caused by plastic deformation. This initiates cracks at the matrix/primary carbide interface, leading to material loss in the form of large chips. In contrast, the steel with a harder matrix shows reduced wear due to its resistance to plastic deformation. Initially, wear occurs through the fracture of primary carbides. However, with prolonged loading, the matrix begins to soften, adopting a wear mechanism similar to the D2 steel with softer matrix. Notably, smaller primary carbides are associated with improved wear resistance by limiting the initiation sites for cracks, especially at the matrix/primary carbide interface. This understanding enables the selection and design of heat treatments to optimize D2 steel microstructure, thus improving resistance to impact-sliding wear damages observed in processes like trimming.

Enhancing elevated-temperature fretting wear performance of GH4169 by tuning wear mechanism through laser shock peening

Turbine disks and blades made of GH4169 for turbine engines are highly prone to fretting wear damage. In this work, we used laser shock peening (LSP) to improve the elevated-temperature fretting wear performance of GH4169, and the corresponding underlying mechanisms are also systematically investigated. Fretting wear experiments conducted on specimens following LSP treatment reveal that the wear resistance of GH4169 was significantly improved, namely a 12.7% reduction in average friction coefficient and a 67.0% decrease in wear rate. Multiscale electron microscopy characterizations reveal that the gradient microstructures induced by LSP serve as the main contributor, which promotes the transition of mechanisms from adhesive wear to abrasive wear, then leading to an exceptional fretting wear performance.

CATHODIC PLASMA ELECTROLYTIC DEPOSITION (CPED) TECHNIQUE FOR SURFACE STRENGTHENING OF TITANIUM AND TITANIUM ALLOYS: A MINI REVIEW

Due to the unique properties of titanium (Ti) and its alloys, it has a particularly wide range of applications in aerospace, automotive, medical and other fields. However, the problems of low surface hardness, high friction coefficient and low wear resistance of Ti alloys limit its development to a certain extent. The destruction of Ti and its alloys often occurs on the surface of materials such as wear damage, corrosion, and oxidation resistance. Therefore, the exploration and application of surface strengthening technology is particularly important. The cathodic plasma electrolytic deposition (CPED) technology, as a surface modification technology, can achieve better adhesion and facilitate the material to achieve better comprehensive performance. This paper briefly introduces the basic concepts, principles and development progress of CPED. Starting from the preparation of ceramic coatings, metal coatings, diamond-like carbon films and composite coatings, it summarizes the application of CPED in Ti and its alloys. Applications in alloys to improve thermal oxidation resistance, wear resistance, corrosion resistance, and film-based adhesion. At the end, its development in the new era environment is prospected.

A multi-physics coupling analysis to predict stress corrosion characteristics of wires in rope under wear damage

To study the stress corrosion characteristics of wire with different wear conditions, namely depth, cross angle and length, Finite Element (FE) models of worn wires are developed based on multi-physics coupling analysis. The electromechanical parameters required for the FE simulations are determined from experimental testing. Then, the stress corrosion characteristics, i.e. stress, corrosion voltage, and corrosion current density, of the wear surface under different tensile displacements are obtained. The results show that the stress increases uniformly under different tensile displacements. However, different wear states present different stress corrosion characteristics. When the tensile displacement or wear state is sufficient to cause plastic deformation of worn wire, the corrosion characteristics changes dramatically.

Electrochemical study on the fretting corrosion synergistic damage mechanism of 316L SS in different dissolved oxygen solution

Nowadays, material aging issues in the nuclear industry have received wide attention as they need costly maintenance strategies to deal with. Therefore, it is important to study the degradation mechanism of materials to improve their service life. In this study, in-situ electrochemical measurement techniques were used to investigate the fretting corrosion synergistic damage mechanism of 316L SS tube against zirconia ceramics plate in the solution with different dissolved oxygen (DO) concentrations. The results show that a more uniform passive film with the main composition of corundum oxides γ-Fe2O3 and oxyhydroxide γ-FeOOH formed on the wear scar under higher DO concentration, which hindered the charge transfer and improved corrosion resistance. The passive film modifies contact pressure and changes wear behavior, resulting in a 55.5 % reduction in the fretting corrosion damage. The main damage mechanism changes from abrasive wear to a mixing mechanism of surface fatigue and abrasive wear. The contribution of the synergistic damage effect was quantified, which is the key part of fretting corrosion damage and weakens with the increase of DO concentration. According to the experimental results, a prediction model of corrosion-induced wear damage was proposed based on the Archard equation, Hertz contact theory, and passive film coverage model.

Atomic-scale simulations of constant-load scratching of gallium nitride under monolayer graphene lubrication

Reducing the friction and wear of nanodevices are the key to improve the performance of micro/nanoelectromechanical systems (M/NMES). In this paper, a gallium nitride (GaN) substrate coated with a single layer of graphene was constructed using molecular dynamics (MD) simulation, and then scratched with a diamond tip under a constant load. The results showed that graphene can improve the abrasion resistance and hardness of the substrate, and reduce surface wear, temperature, potential energy, and subsurface damage. However, the effect of graphene to inhibit the generation of dislocations within the substrate was not obvious. In addition, the substrate surface exhibited super-lubrication at low load scratching. As the load increased, the friction and wear on the substrate surface increased. The application of graphene can extend the load range over which the substrate undergoes full elastic deformation, which means a greater range of super-lubrication. The protective and lubricating effects of graphene provide guidance for the design of GaN-based nanodevices.

Analysis of the wheel-rail dynamic response characteristics and damage to the fixed frog of the No. 3 tram turnout

The tram No. 3 turnout fixed frog uses a variation in the depth of the flange groove so that the wheel rolls over the frog area in a continuous flange bearing. This method of travelling over the turnout requires the wheel load to transition back and forth between the tread and the flange, resulting in wheel-rail impact, which in turn affects service life. In order to investigate its service characteristics, this paper has established a transient wheel-rail rolling contact finite element model for the No. 3 turnout fixed frog. The macroscopic dynamic response and microscopic wheel-rail contact solution as the tram passes through the turnout at different axle weights and speeds are analysed in detail, and the changing patterns of wear and fatigue damage are investigated. The research shows that rail wear is particularly severe in the wheel flange bearing area, approximately 1.6 times greater than in the tread bearing area. In addition, when tram speeds are reduced to 15 km/h, there is a significant reduction in wheel-rail impact and wear, thereby improving ride smoothness and safety. The results of this study are of great significance to the operation and maintenance of the No.3 fixed frog turnout.

Control principles of individual traction electric drive of a front loader

Background. The operation of technological machines is associated with constant slipping of driving wheels, which can lead to increased tire wear and soil damage. This determines the relevance of works aimed at research and reduction of slip.
 The aim of the work is to analyze the considered control strategies of individual traction electric drive of front loader from the point of view of driving wheels slipping.
 Methods. The paper considers three control strategies of individual traction electric drive of a front loader - initial, with equal degrees of utilization of electric motors of wheels (strategy 1), simulation of blocked drive (strategy 2), as well as a variant of organization of traction control system (strategy 3). Using a simulation computer model of dynamics, the working process of the front loader was investigated during bulldozing operations, as well as during acceleration.
 Results. It was obtained that when bulldozing, the application of strategy 2 allows to provide almost the same slip coefficient of the driving wheels, which potentially allows to reduce tire wear and fuel consumption (compared to strategy 1). The application of strategy 3 in such conditions turned out to be inexpedient, as the slip limitation in this case will limit the speed of the operation. The simulation of the front loader acceleration process showed some advantage of strategy 3 over the others in terms of energy consumed.
 Conclusion. According to the results of the study, it was determined that when the front loader performs heavy technological operations such as bulldozing, it is rational to use control strategy 2, which simulates a locked transmission. In the case of the acceleration process, which is typical for transportation operations and driving on public roads, it is effective to use strategy 3.

Effects of Humidity on Tribological Properties of 8YSZ/C Coating Designed by the Combination of Thermal Spraying and Hydrothermal Reaction

Thermal spraying ceramic coatings have been widely used to prevent wear damage. However, the poor lubricating ability seriously restricted their application. In this article, zirconia stabilized by 8 wt% yttria (8YSZ)‐C composite coating is prepared with the combination of in‐situ synthesis carbon microspheres in the pores of as‐sprayed 8YSZ coating by hydrothermal reaction. The chemical constituents and morphologies of the synthesized powders and the composite coatings are analyzed by scanning electron microscope (SEM) and X‐ray diffraction (XRD). The microstructure and tribological behaviors of the composite coating are studied by SEM, TEM. and Raman analysis. The influence of humidity on the structural evolution of carbon microspheres during sliding wear process is discussed. The results show that the synthetic C powders exhibit a typical spherical structure. Meanwhile, carbon microspheres adhere to the pores of the 8YSZ coating. The friction and wear experiments in different humidity show that the re‐graphitization of amorphous carbon becomes extremely obvious with the increase of humidity. Under the 80% humidity, an ordered graphene nanoscroll structure is formed, resulting in the optimization of the tribological properties. Furthermore, the friction coefficient of composite coating is reduced to 0.18, and its wear rate is about 1 times lower than that of under the 10% humidity.