Wear Failure Research Articles

The Use of Large Metal Heads in Thin Vitamin E–Doped Cross-Linked Polyethylene Inserts Does Not Increase Polyethylene Wear in Total Hip Arthroplasty: 5-Year Results From a Randomized Controlled Trial

BackgroundVitamin E–doped cross-linked polyethylene (VEPE) has encouraged the use of larger heads in thinner liners in total hip arthroplasty (THA). However, there are concerns about wear and mechanical failure of the thin liner, especially when metal heads are used. The aim of this randomized controlled trial was to investigate if the use of a large metal head in thin VEPE liner would increase polyethylene wear compared with a standard 32-mm metal head and to compare periacetabular radiolucencies and patient-reported outcomes in THA. MethodsThere were 96 candidates for uncemented THA who were randomly allocated to either the largest possible metal head (36 to 44 mm) that could be fitted in the thinnest available VEPE liner (intervention group) or a standard 32-mm metal head (control group). The primary outcome was proximal head penetration, measured with a model-based radiostereometric analysis. Secondary outcomes were periacetabular radiolucencies and patient-reported outcomes. The midterm results of the trial at 5 years are presented. ResultsThe median total proximal head penetration (interquartile range) was −0.04 mm (−0.12 to 0.02) in the intervention group and −0.03 mm (−0.14 to 0.05) in the control group (P = .691). The rates of periacetabular radiolucencies were 1 of 44 and 4 of 42 (P = .197), respectively. Patient-reported hip function and health-related quality of life did not differ between the groups, but participants in the intervention group reported a higher level of activity (median University of California Level of Activity score 7 versus 6, P = .020). There were 5 revisions caused by dislocations (2), periprosthetic fracture (1), stem subsidence (1), or iliopsoas impingement (1). ConclusionsLarge metal heads in thin VEPE liners did not increase liner wear and were not associated with liner failure 5 years after THA.

Classification of Progressive Wear on a Multi-Directional Pin-on-Disc Tribometer Simulating Conditions in Human Joints-UHMWPE against CoCrMo Using Acoustic Emission and Machine Learning

Human joint prostheses experience wear failure due to the complex interactions between Ultra-High-Molecular-Weight Polyethylene (UHMWPE) and Cobalt-Chromium-Molybdenum (CoCrMo). This study uses the wear classification to investigate the gradual and progressive abrasive wear mechanisms in UHMWPE. Pin-on-disc tests were conducted under simulated in vivo conditions, monitoring wear using Acoustic Emission (AE). Two Machine Learning (ML) frameworks were employed for wear classification: manual feature extraction with ML classifiers and a contrastive learning-based Convolutional Neural Network (CNN) with ML classifiers. The CNN-based feature extraction approach achieved superior classification performance (94% to 96%) compared to manual feature extraction (81% to 89%). The ML techniques enable accurate wear classification, aiding in understanding surface states and early failure detection. Real-time monitoring using AE sensors shows promise for interventions and improving prosthetic joint design.

Experimental study on wear failure of spindle hook teeth of cotton picker

Introduction: The wear failure of spindle will lead to a decrease in cotton harvesting rate of the cotton picker during field operation and serious wastage.Method: Three types of spindle samples at different installation positions and working areas were obtained through field experiments to explore the wear failure law of spindle hook teeth of cotton picker during field operation. Hardness of hook tooth coating and substrate of spindles were tested, surface and cross-section microstructure of the spindle hook teeth were characterized, and wear area and width of the spindle hook teeth were extracted.Results: Results showed that the hardness of the hook tooth coating is evidently higher than that of the substrate; the average coating hardness of the No. 3 spindle hook teeth reaches the maximum at 1033.6 HV0.1; defects, such as microcracks and micropores, exist in the coating of the three types of spindle hook teeth; and the thickness of the coating is between 70 and 130 μm. The wear area of spindle hook tooth changes exponentially and the wear width changes linearly with the increase of field operation area at the same installation position. The wear area and width of the spindle hook teeth gradually increase with the decrease of the installation height and the wear change of the hook teeth is negatively correlated with the installation height in the same field operation area.Discussion: The wear failure of spindle hook tooth is mainly caused by abrasive, fatigue, and oxidation wear. The results of this study can provide a reference for improving the wear resistance of spindle hook teeth.

Wear and Friction Behaviour of Additive Manufactured PEEK under Non-conformal Contact

Tribological properties of laser sintered polyether-ether-ketone (EOS PEEK HP3) were investigated using a rolling-sliding test rig. This investigation aimed to study the wear and friction failure mechanism of EOS PEEK HP3. The main objectives included to conduct wear and friction tests under non-conformal contact, to monitor surface temperature, to carry out surface characterization with microscopy. With this rolling-sliding test rig, tests were carried out on an EOS PEEK HP3 specimen running against a steel disc unlubricated, with various slip-ratios under a contact pressure of 56 MPa, 48 MPa and 39 MPa respectively. Both wear and friction were measured. The results have shown that both friction and wear were increased with an increase of either slip-ratios or the contact pressures, exacerbated by high surface temperatures. It has also been observed that both friction and wear failures were associated with the degradation of the non-conformal contact surfaces due to crystallinity changes that correlated well with working conditions. Using microscopy it was found that such failures as pitting, fatigue and surface cracking were affected by the surfaces in contact, including the degree of melting of the surface. Based on the observation on the contact surfaces, the failure mechanisms of EOS PEEK HP3 include surface melting and contact fatigue failures with the high slip-ratio and the high contact pressure conditions. The findings of this investigation have the potential to help to design & develop additive manufacturing PEEK products. Typically, these results can be used in a design process for a more effective polymeric gear system.

Erosion Wear Characteristics and Failure Mechanism of the Sulzer Oil Pump

Erosion Wear Characteristics and Failure Mechanism of the Sulzer Oil Pump

Numerical simulation study of high-speed lip seal considering eccentricity

PurposeThis paper aims to focus on the high-speed rotary lip seal in aircraft engines, combining its service parameters, its own structure and application conditions, to study the influence of different eccentric forms, eccentricity, rotational speed and other factors on the performance of the rotary lip seal.Design/methodology/approachA numerical simulation model for high-speed eccentric rotary lip seals has been developed based on the theory of elastic hydrodynamic lubrication. This model comprehensively considers the coupling of multiple physical fields, including interface hydrodynamics, macroscopic solid mechanics and surface microscopic contact mechanics, under the operating conditions of rotary lip seals. The model takes into account eccentricity and uses the hazardous cross-sectional method to quantitatively predict sealing performance parameters, such as leakage rate and friction force.FindingsEccentricity has a large impact on lip seal performance; lips are more susceptible to wear failure under static eccentricity and to leakage failure under dynamic eccentricity.Originality/valueThis study provides a new idea for the design of rotary lip seal considering eccentricity, which is of guiding significance for the engineering application of rotary lip seal.

Correlation between microstructure, mechanical properties, and slurry erosion behavior of hot-rolled dual-phase steel

A low alloy dual-phase steel was produced via a thermo-mechanical control process to improve production efficiency and reduce costs. The study investigates the influence of martensite volume fractions on the mechanical properties and slurry erosion behavior of the hot-rolled dual-phase steel, and the correlation between the mechanical properties and slurry erosion behavior was revealed to provide insights into the material's wear resistance. Microstructure of dual-phase steel with varying martensite were characterized, and nanohardness, Vickers hardness, tensile propertiy, and slurry erosion were tested. Result indicates that martensite content significantly affects the mechanical propertiy of the hot-rolled dual-phase steel. Hardness and strength increase with increased martensite content, exhibiting a linear relationship. The main strengthening mechanisms are dislocation and solid solution strengthening. Slurry erosion result reveals that matrix hardness, martensite content/size, and work hardening ability significantly impact the slurry erosion performance of hot-rolled dual-phase steel. Martensite plays a crucial role in resisting wear failure, with higher content and larger size providing better protection to the soft ferrite and reducing erosion weight loss. Work hardening ability also leads to a decrease in periodic erosion weight loss.

Optimized Design of Pipe Elbows for Erosion Wear

Multiphase flows are widely used to transport solid–liquid mixtures in oil and gas fields. The pipeline structures used can suffer damage from the high-pressure sand-carrying fracturing fluid, causing erosion and wear failures in the engineering field. In this work, an erosion model that considers particle turbulent kinetic energy and the effect of the design’s structural parameters on the erosion wear of spatial pipe structures is established using computational fluid dynamics (CFD). Structural parameters such as the bending diameter ratio, bending angle and spatial angle are discussed, and the location and degree of each parameter with regard to the erosion rate are obtained. The results show that the included angle of the pipe elbow has the greatest influence on erosion wear among the structural parameters. Several typical anti-erosion optimization models are compared and analysed, and a corrugated anti-erosion structure based on a bionic structure is further proposed. It is found that the anti-erosion performance of the T-type blind long header pipe is better in terms of the numerical value of the erosion rate, while for the erosion cloud diagram, the anti-erosion performance of the corrugated structure is superior. Finally, some suggestions for the application of the anti-erosion structure in the engineering field are given, and technical support is provided for the anti-erosion structure design and practical application of space pipeline systems in the future.

Wear state assessment of external gear pump based on system-level hybrid digital twin

Modeling technology is both the core and the difficulty of digital twin. In response to this challenge, a digital twin framework based on dynamic model is proposed and applied to fault prognostic and health management (PHM) of fuel control system. Taking the wear failure of external gear pump as an example, the system-level hybrid digital twin model is introduced. Firstly, based on the first principle, the dynamic model of the fuel control system is established to realize the mirror image of the physical entity, and the fault sensitive parameters that need to be updated in the physical model are defined according to the prior knowledge. Then, combined with deep reinforcement learning, an autonomous learning strategy of virtual entity is constructed, achieving updating and iteration of dynamic model. Finally, an interpretable gear pump wear assessment model is built, and the wear state is evaluated by the distance of the model output vector. From the results, the proposed method can ensure the real-time consistency of virtual entity and physical entity under different working conditions, and realize the wear assessment of external gear pump.

Analysis on the Dynamic Behavior of Space Shafting under Combined Load

The space shafting is the core component of the momentum exchange attitude control actuator for spacecraft.The dynamic behavior of space shafting has an important impact on the performance of the actuators. Based on the dynamic theory of rolling bearing, this paper presents a dynamic analysis model of space shafting for the interaction between bearing balls and oil-containing nonmetallic cage under combined loads. Also, the accuracy of the analysis model was verified through a high-speed camera system to conduct a cage speed test. In addition, the dynamic behavior of balls and cage under combined loads and the interaction between them is also analysed. The results show that the axial displacements of balls fluctuate periodically under combined loads, and the rotation speeds of balls and cage are easily affected by the load, presenting as the oscillation of speed. Also, the force between balls and cage increases as the load increases. The dynamic behavior of balls and cage could be effectively improved by avoiding excessive torque loads and limiting the axial preload to 40 N. The wear failure caused by unstable operation of bearings cannot be ignored. This model is more practical in completing simulation analysis of different operating conditions and structural parameters of the shafting system. It provides a theoretical reference for the structural design and performance analysis of space shafting.

Microstructure evolution and tribo-oxidation induced by friction and wear of cast iron brake discs

Braking discs play an important role for the safety of vehicles whereas severe frictional contacts in repeated braking operations result in thermal and tribological failures. This paper reports comprehensive surface and subsurface analyses of a used grey cast iron braking disc to investigate its failure mechanisms as well as related microstructure evolution. Thermal cracking, spalling wear and tribo-oxidation have been found to contribute to the wear failure. The flake-type graphite of the grey cast iron triggered propagation and internal oxidation of the metallic matrix. In a depth of 3 mm beneath the rubbing surface, extensive microstructure evolution occurred by severe plastic deformation of the ferritic matrix, nodularisation and partial dissolution of the lamellar carbides, and internal oxidation. The microstructure evolution resulted in decreased surface hardness to HV0.3 247 as compared to HV0.3 284 of the bulk cast iron.

Properties and elevated temperature wear mechanism of pure copper and TiC/Cu nanocomposites

The properties and elevated temperature wear mechanism of pure copper and in situ TiC/Cu matrix composites fabricated via combustion synthesis assisted with hot press were investigated. Brinell hardness, compression properties and electrical conductivity were studied. It was found that of the Brinell hardness, yield strength and compressive strength of the composites is higher than sintered pure copper, however, the electrical conductivity and fracture strain of the composites are lower. Dry sliding friction and wear tests showed that the worn surface transformed from furrow to spalling pit and the wear rate increases with the increasing temperature and applied load, the wear failure changes gradually from surface plastic deformation, plough wear and oxidation wear to abrasive wear and fatigue spalling wear.

Prediction of fatigue limit stress in C/SiC composites: Effect of stochastic load spectrum

AbstractUnder cyclic‐fatigue loading, stochastic loading may occur and affect the fatigue limit stress (FLS) in C/SiC composites. In this paper, the FLSs in different C/SiC composites were predicted considering stochastic loading spectrums. Damage mechanisms of interface wear and fibers failure were considered in the global load sharing criterion to determine the fracture life and fiber's failure probability in three different stochastic loading spectrums, that is, constant, increasing and decreasing stochastic stress spectrum. Experimental FLS and fatigue life degradation rate were predicted using the developed micromechanical approach, and the effect of cyclic duration under stochastic spectrums on the FLS was analyzed. Relationships among the FLS, life degradation rate, stochastic spectrum, and cyclic duration were established.

Study on the role of chromium addition on sliding wear and corrosion resistance of high-manganese steel coating fabricated by wire arc additive manufacturing

Guide shoe made of steel is an important component of coalcutter and rail transport to sustain forward direction. However, the guide shoe suffers from wear failure due to the heavy load and fatigue. Preparing wear-resistance coating on the worn surface is a practical and economic technology to elongate longevity. High manganese steel is a candidate material with excellent wear resistance. In this study, high-manganese (HiMn) and high-manganese medium-chromium (HiMnMeCr) coatings are fabricated by using wire arc additive manufacturing (WAAM) to investigate the role of Cr addition on the microstructure and resistance to wear and corrosion by analyzing the microstructure morphology, wear rate, coefficient of friction, surface and cross-sectional morphology of the wear track, and electrochemical behavior by using sliding wear test and electrochemical experiment. The experimental results obtained by using the counterface material of ZrO2 showed that Cr addition changed the microstructure constitutes of WAAMed HiMn coating from biphasic austenite + martensite to single austenite. The addition of Cr elongated the running-in period of the wear process and weakened the wear resistance of the WAAMed HiMnMeCr coating due to the work-hardening effect induced by the severe plastic deformation of austenite. At loads of 50 and 100 N, the primary wear mechanism for the HiMn coating was a complex mode of abrasive and adhesive wear. The wear mechanism transformed into a single adhesive wear at a load of 120 N. However, the primary wear mechanism of the HiMnMeCr coatings was abrasive wear at all tested loads. The electrochemical experiment (pote ntiodynamic curves and EIS analysis) shows that the corrosion resistance of HiMnMeCr coating was better than that of HiMn coating, indicating that the addition of Cr enhanced the corrosion resistance of the WAAMed HiMn steel by the passivation effect of Cr. This study will provide a fundamental theory for the fabrication of wear-resistance coating by using WAAM.

Dynamic Analysis of the Guiding Shoe considering Contact Gap and Pose Disturbance

The pose disturbance of the guide shoe under complex working conditions can lead to collision, impact, and wear failure between the guide shoe and the pin row. To explore the damage law of pose disturbance on the guiding shoe, a rigid‐flexible coupling dynamic model of the walking mechanism considering the contact gap between the guiding shoe and the pin row was constructed. The contact characteristics of the guiding shoe under different poses were analyzed. The results indicate that the swing around the x‐axis has the most significant impact on the guiding shoe, with stress concentration primarily occurring near the corner of the trench. The posture of swinging solely around the y‐axis weakens the supporting effect of the guide shoe, resulting in stress concentration on the end face of the left side face. Swinging around the z‐axis results in stress concentrations on the upper faces of the shoe. Research shows that the angular velocity of the guiding shoe around the x‐axis and z‐axis is highly sensitive to variations in traction speed. In addition, an increase in lateral force weakens the support effect of the guiding shoe, resulting in elevated contact force on the lower side of the guiding shoe and increased y‐direction load on the walking wheel. The research results provide a reference for exploring the influence of walking unit postures on the failure of the guiding shoe and for improving shearer traction reliability.

Hysteresis Stress, Strain and Penetration Analysis of Spur Gear Assembly for Various Sustainable Design

This paper considers and compares the hysteresis stress and strain and the penetration property of spur gear assemblies based on three unique designs. Spur gear plays an important part in mechanical structures, and any mechanical setup should consider the execution of such a mechanical component under distinct designs to improve its mechanical productivity and sustainability. To explore the ways in which the mechanical behaviour of the designs varies with the design configurations, we integrate simulation analysis with an experimental study. The outcomes of this paper indicate considerable differences in both hysteresis stress, strain distribution, and penetration behavior measurements between three designs. The paper explains the stated disparities by the unique geometric layouts and material characteristics of each design. Furthermore, it emphasizes that some of the examined designs have lower hysteresis losses and favourable stress and strain distributions, which positively affects the long-term performance of gear systems. Other designs, however, exhibit severe penetration and stress concentrations leading to rapid gear wear and likely premature failure. In distinguishing these events, the present study offers a valuable approach to the parameters that influence the performance of gear systems and aids in the improvement of the design methodology.

Failure Mechanism of Bearings under Extremely Cryogenic Conditions

Bearing, as one of the most core components of rotating equipment, is prone to wear under cryogenic conditions, which seriously affects the efficiency of the whole system. Therefore, it is necessary to study the failure mechanism of bearing under cryogenic conditions. In this paper, friction and wear behavior of the bearings under cryogenic conditions is verified by using bearing simulation test platform. The results show that the bearing surface of raceway is prone to wear failure under cryogenic conditions, but the ball wear amount per unit time is small. This is because the cryogenic conditions seriously change the performance of the bearing material, the plasticity and strength of the material will be seriously reduced, and the brittleness will increase. Therefore, when the bearing ball and the bearing raceway surface contact friction, under the action of Hertz contact stress, the raceway surface is easy to produce pits and spalling, resulting in serious fatigue on the surface of the friction pair. The research provides a strongly theoretical and technical support for further improving the bearing performance and developing the tribological design of bearings.

Effect of two strengthening processes on the fretting wear mechanism of CoCrMo alloy

To alleviate fretting damage of the artificial joint CoCrMo alloy, the substrate was treated by ultrasonic surface rolling process (USRP) and solid solution treatment (SST) respectively. Meanwhile, the fretting wear behavior and failure mechanism of the treated-samples were quantitatively analyzed via experimental study. Compared with the substrate, the wear rates of USRP and SST samples are reduced by about 8.895 and 13.463 µm3/mJ in slip regime. In addition, the wear resistance of USRP samples is improved due to grain refinement, but the expanded grain boundary channels aggravate the oxidative wear degree (8.13% higher than substrate). The intergranular carbides are dispersed in grains and constructed into stacking faults through SST, hence, the fretting wear resistance of the alloy is greatly improved.

Unveiling the mechanical properties of near-surface microstructures in tribological contacts via in-situ micro-bending tests

This study demonstrates the application of the in-situ V-notched micro-cantilever bending method in tribology by analyzing three distinct cases of near-surface microstructures occurring in common tribological contacts. The brown etching layer region of a rail wheel from service shows predominant plastic material behavior. Significant variations in material response and crack initiation are revealed in distinctive regions of a roller bearing's near-surface microstructure and a self-lubricating laser cladding. Qualitative analysis and stress-displacement graphs highlight the method's potential for gaining high-resolution insights into material behavior, contributing to our understanding of microstructural changes affecting friction, wear, and component failure in tribosystems.

Fault diagnosis of horizontal centrifugal pump orifice ring wear and blade fracture based on complete ensemble empirical mode decomposition with adaptive noise-singular value decomposition algorithm

Horizontal centrifugal pump orifice ring wear and blade fracture failure will not only affect the hydraulic performance but also affect the safety and stability of the whole unit. In this paper, the horizontal centrifugal pump orifice ring wear and blade fracture failure are studied, and carry out condition monitoring and fault identification through the vibration signal under the failure. Combined with the Complete Ensemble Empirical Mode Decomposition with Adaptive Noise and Singular Value Decomposition algorithm of adaptive noise, a vibration feature extraction method of horizontal centrifugal pump based on intrinsic mode singular value is proposed. Through the BP neural network, based on the time domain, frequency domain, wavelet packet-AR spectrum, and intrinsic mode singular value characteristics of single-point and double-point vibration, the identification model is constructed and the identification effect is compared. The research shows that the vibration feature recognition effect of CEEMDAN-SVD decomposition is verified based on BP neural network model, and the BP neural network is improved by Particle Swarm Optimization to further improve the recognition effect and speed, which provides the diagnosis model for the design of subsequent diagnosis system.