Fretting Wear Experiments Research Articles

Comparative analysis of fretting wear behavior of steel wire subject to tensile-torsional coupling forces in typical mining environments

The complex mining environments can significantly accelerate the fretting wear among steel wires within wire rope, thereby diminishing its service life and posing severe risks to the safety of mine hoisting operations. To explore the fretting behavior of steel wires featuring complex contact structures in typical mining environments, a customized test rig was utilized to perform fretting wear experiments of steel wire under tensile-torsional coupling forces. The findings indicate that with increasing contact force, the coefficient of friction (CoF) between steel wires in different environments decreases, whereas the frictional force and wear degree increase significantly. The wear depth and wear coefficient under peak contact structure are markedly larger than those under valley contact structure. For the same contact force, the wear of steel wire without lubrication is the largest, the wear under water lubrication is the second, and the wear under grease lubrication is the least. The primary wear mechanisms of steel wire under grease lubrication are abrasive wear and fatigue wear. The presence of mineral particles in the grease can reduce the CoF, but it will exacerbate the wear and result in adhesive wear characteristics on the wear surfaces. Under no lubrication and water lubrication conditions, the wear mechanisms encompass abrasive wear, adhesive wear and fatigue wear. Furthermore, with increasing contact force, the fatigue wear of steel wire under no lubrication intensifies, while the abrasive wear characteristics become more pronounced under water lubrication.

Preparation and friction wear performance of ZrO2/MoS2 PEO composite coating

PEO composite coatings doped with ZrO2 and MoS2 particles were prepared on the surface of TC21 alloy using the PEO process. The morphologies and phase compositions of the coatings were analyzed using FE-SEM, TEM, XRD refinement and XPS. The tribological and self-lubricating properties of the coatings were investigated through fretting wear experiments. The results indicate co-doping reduced the friction coefficient by approximately 30 %. The co-doped coating demonstrated higher crystallinity, whereas the ZrO2 coating contained a significant amount of amorphous material. The wear mechanisms of the coating included three-body abrasive, adhesive, and oxidative wear. The self-lubricating properties of the coating were derived from the presence of MoS₂ and the destruction and deformation of the coating surface during fretting wear.

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.

Fretting Wear Behaviors of Silicone Rubber under Dry Friction and Different Lubrication Conditions.

The fretting wear behaviors of silicone rubber under dry friction and different lubrication conditions are studied experimentally. Water, engine oil, dimethyl silicone oil (DSO), and dimethyl silicone oil doped with graphene oxide (DSO/GO) are selected as lubricants. Under the liquid lubrication conditions, the silicone rubber samples are always immersed in the same volume of lubricant. The contact model of a 440C steel ball and silicone rubber sample is the sphere-on-flat contact. The reciprocating fretting wear experiments are carried out using the reciprocating friction wear tester. A scanning electron microscope and three-dimensional white-light interference profilometer are used to detect the surface wear morphology and obtain the wear volume, respectively. The influences of normal force, lubrication condition, and displacement amplitude on fretting wear behavior are discussed. The fretting wear performances of silicone rubber under different fretting states and lubrication conditions are compared. The results show that for a small normal force, silicone rubber has the best wear resistance under DSO/GO lubrication. While for a large normal force, silicone rubber has the best wear resistance under engine oil lubrication.

An improved energy wear model of three-dimensional ball-plane contact structure and its fretting wear dynamic behaviors study

This paper proposes a method that combines the finite element method with an improved energy wear model to establish a three-dimensional (3D) ball-plane contact structures fretting wear model. The correctness of the model was verified by Hertz contact theory and fretting wear experiments. Then, the fretting wear dynamic behaviors of 3D ball-plane contact structures were investigated in detail. The results show that when the contact structure is in the partial slip regime (PSR), the cross-sectional wear scar profile changes from the “W” shape to the “U” shape along the fretting direction. When the contact structure is in the gross slip regime (GSR), the cross-sectional wear scar profile always maintains a “U” shape along the fretting direction. In addition, it was also found in the study that when the contact structure is at GSR under a low normal load or PSR under a high normal load, it will help reduce wear. This study can provide significant theoretical guidance for reducing and protecting fretting wear in contact structures.

Study on fretting friction properties based on GCr15 alloy and liquid epoxy resin protective coatings on GCr15 alloy

GCr15 alloy steel is a representative alloy steel of high carbon chromium bearing steel, with good comprehensive performance. However, the fretting wear and fatigue at the interface of the GCr15 friction pair greatly reduce its service life. In this study, the friction pair of GCr15 alloy was prepared by the surface treatment of epoxy resin coating. The tangential fretting wear experiments were conducted on the samples with the point contact mode in an SRV-IV multifunctional tester to investigate the evolution law of coefficient of fretting wear, dissipation energy and damage varying with the normal load and displacement amplitude. The results showed that the coefficients of the friction pairs treated with epoxy resin composite materials are lower than those of GCr15-GCr15 friction pairs under the same normal load and displacement amplitude, and the friction coefficients of both types of friction pairs gradually decreased with the increase of normal load and the decrease of displacement amplitude. At the same time, epoxy resin coating treatment reduced the dissipation energy of fretting wear. From the perspective of damage protection, GCr15-GCr15 exhibits severe scratch damage, micropores, and microcracks after friction experiments, while the epoxy resin coating mainly showed furrow. In addition, the decrease in hardness of polymer composite coating increased the wear rate of the samples to a certain extent.

A comparative study on the electrical contact behavior of CuZn40 and AgCu10 alloys under fretting wear: Effect of current load

The current load is one of the most significant factors in the reliability of electrical contact under fretting conditions. In this paper, the fretting wear experiments are conducted for CuZn40 and AgCu10 alloys with varied current loads. The variations of electrical contact resistance (ECR), ECR endurance, temperature, and wear volume with the increasing current load of two alloy materials under fretting conditions are investigated, and the differences between their electrical contact behaviors are compared. The microstructures of the surface wear morphology are examined to reveal the mechanisms of fretting wear and electrical contact failure. In addition, the fretting wear volume evolution of both alloys under different fretting cycles is studied. The results show the current load impacts the wear morphology. The wear particles become smaller and the oxide layer becomes stable with the increase of current load. The effect of current load on ECR and temperature is more significant for CuZn40 alloy. The ECR endurance for both materials first increases and then decreases. This is attributed to two competitive mechanisms controlling the evolution of ECR endurance under varied current loads.

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.

Electrical contact resistance endurance of AgNi10 alloy under fretting wear: Experiment and numerical prediction

Fretting wear is an essential factor affecting electrical contact resistance (ECR) endurance. In this paper, fretting wear experiments are conducted on AgNi10 with various fretting amplitudes and normal forces. The relationship between the ECR endurance and wear volume is established. Based on the experimental results, a numerical approach is proposed to predict the ECR endurance under fretting wear conditions. A three-dimensional fretting wear model is established by utilizing the commercial software ABAQUS. The elastoplastic constitutive model of AgNi10 alloy is taken into consideration. The calculation of the wear profile and wear volume is based on an energy dissipation wear model through the UMESHMOTION subroutine. The ECR endurance is then predicted by using the wear volume from the simulation. The validation of the proposed numerical approach is conducted by comparing the numerical results of the wear profile, wear volume, and ECR endurance with the experimental data. It indicates that this combined experimental and numerical approach can provide accurate predictions on the ECR endurance under various fretting wear conditions.

Study on Wear Debris Distribution and Performance Degradation in Low Frequency Fretting Wear of Electrical Connector

Aiming at the problem of the deterioration of the contact performance caused by the wear debris generated during the fretting wear of the electrical connector, low-frequency fretting wear experiments were carried out on the contacts of electrical connectors, the accumulation and distribution of the wear debris were detected by the electrical capacitance tomography technology; the influence of fretting cycles, vibration direction, vibration frequency and vibration amplitude on the accumulation and distribution of wear debris were analyzed; the correlation between characteristic value of wear debris and contact resistance value was studied, and a performance degradation model based on the accumulation and distribution of wear debris was built. The results show that fretting wear and performance degradation are the most serious in axial vibration; the characteristic value of wear debris and contact resistance are positively correlated with the fretting cycles, vibration frequency and vibration amplitude; there is a strong correlation between the sum of characteristic value of wear debris and the contact resistance value; the prediction error of ABC-SVR model of fretting wear performance degradation of electrical connectors constructed by the characteristic value of wear debris is less than 6%. Therefore, the characteristic value of wear debris in contact subareas can quantitatively describe the degree of fretting wear and the process of performance degradation.

Effect of coating prepared using CuNiIn mixed with graphite and MoS2 on fretting wear behaviour of Ti6Al4V

• Graphite and CuNiIn were plasma sprayed onto Ti6Al4V to get self-lubricating coating. • Addition of graphite to CuNiIn powder reduced the friction coefficient in fretting. • Presence of MoS2 at the contact surface further reduced the friction coefficient. • Effect of MoS2 at the contact surface was significant in CuNiIn + Graphite coating. In the present study, solid graphite was mixed with CuNiIn powder and plasma sprayed onto Ti6Al4V to develop a self-lubricating coating (CuNiIn + Gr). Fretting wear experiments were done at room temperature on uncoated Ti6Al4V samples and samples coated with CuNiIn + Gr composite powder and CuNiIn powder. The counterbody used was alumina ball. Inclusion of graphite in CuNiIn reduced the friction coefficient owing to graphite acting as a self-lubricant. To study the effect of solid lubricant MoS 2 , some tests were done after applying MoS 2 on the surface of the samples. The presence of MoS 2 reduced the friction coefficient in all samples. The reduction was more in CuNiIn + Gr coated samples, which can be related to the synergetic effect of both the solid lubricants.

Modeling adhesive and abrasive wear phenomena in fretting interfaces: A multiphysics approach coupling friction energy, third body and contact oxygenation concepts

The purpose of this research work is to develop an extended friction-energy Wear approach taking into account the presence of debris layer and adhesive wear by simulating the interfacial di-oxygen partial pressure using an Advection-Dispersion-Reaction approach. This multiphysics modeling estimates locally if the fretted interface is running under adhesive or abrasive wear condition. For each situation, a specific energy wear coefficient is considered which finally allows the simulation of the composite adhesive-abrasive (W-shape) fretting scar. A good correlation is observed with former Ti-6Al-4V cylinder-on-flat fretting wear experiments. This model also predicts the transition from pure abrasive to abrasive-adhesive response, W-shape and U-shape fretting scar profiles and for the first time provides reliable estimations of the maximum wear depth extension.

Comparative study on the fretting wear property of 7075 aluminum alloys under lubricated and dry conditions

This paper investigates torsional-fretting wear properties of 7075 aluminum alloys under lubricated and dry conditions. Fretting wear experiments are conducted under the flat-on-flat contact configuration, followed by the friction torque, dissipated energy and wear volume analyses. The worn area morphology, wear mechanism and tribo-chemical behavior are examined by the optical microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy, etc. The fretting behavior is obviously affected by a collective effect of the lubricating medium, third body behavior and contact configuration. Abrasion wear by micro-cutting of debris is detected on the oil lubricated worn surfaces. The abrasion, cracks and delamination are commonly exist on the seawater lubrication and dry fretting worn surfaces. Corrosion pits and an oxidation debris layer can be observed under the former and latter test conditions, respectively.

Investigations on torsional fretting wear properties of CuAlNi processed by ultrasonic vibration-assisted milling

This paper investigates the effects of parameters of ultrasonic vibration-assisted milling (UVAM) on torsional fretting wear properties of CuAlNi. Surface texture is processed on CuAlNi surfaces by the UVAM method. Fretting wear experiments on the CuAlNi surfaces are carried out by the torsional wear test rig. Further surface topography measurements using three-dimensional (3D) surface profiler, relationships between the UVAM parameters and the fretting properties of UVAM-processed samples were established. The results indicated that the UVAM-processed samples showed excellent antiwear and antifriction properties in comparison with untreated CuAlNi; this improvement is mainly due to the enhancement on abilities of storing lubricated oil and catching wear debris during the fretting wear process, as well as the increased hardness.

Experimental investigation of fretting wear of coated spring clip and inlet ring in land-based gas turbines at elevated temperature

The objectives of this investigation were to characterize the friction and fretting wear behavior of coated inlet ring and spring clip components used in land-based gas turbines at elevated (500 °C) temperature. In order to achieve the objective, a novel high temperature fretting wear apparatus (HTFWA) was designed and developed to simulate the conditions existing in a gas turbine. Sections of actual inlet ring and spring clip were cut from a gas turbine and used in the test apparatus. The test apparatus was used to investigate fretting wear of APS sprayed Cr3C2–NiCr (25% wt.), HVOF sprayed Cr3C2–NiCr (25% wt.), HVOF sprayed T-800 and APS sprayed PS400 coated inlet rings against HVOF sprayed Cr3C2–NiCr (25% wt.) coated spring clip. Fretting wear experiments were conducted with normal loads up to 400 N at a fixed displacement amplitude of 0.5 mm and frequency of 5 Hz. A proximity probe was used for in-situ wear depth measurement at the spring clip and inlet ring contact pair. The results indicate that the combination of PS400 coating on inlet ring and HVOF Cr3C2–NiCr on spring clip wear the least as compared to other combinations in both running-in condition and under steady state regime. PS400 also demonstrated a 50% reduction in coefficient of friction as compared to other coatings at 500 °C. Further, a theoretical approach was developed to estimate the evolution of wear depth with sliding distance for a cylindrical contact configuration using Archard's wear law. The experimental and theoretical results were found to be in good agreement with each other.

Multi-axis Direction Fretting Fatigue and Fretting Wear Test System and Testing Method

The present work deals with fretting test apparatus and method. A multi-axis direction fretting fatigue and fretting wear test system is designed in order to simulate fretting fatigue and fretting wear more closely. The multi-axis direction fretting fatigue experiments of point, line and surface contact modes can be realized by different fixture combinations, and the radial/tangential fretting wear experiments can also be realized. It can realize the application of bending alternating load and normal load. The size and frequency of load can also be changed.

Tribological performance of graphite-like carbon films with varied thickness

Graphite-like carbon (GLC) films with different thickness were deposited on 316 L stainless steel using closed field unbalanced magnetron sputtering system to investigate the influence of film thickness on the microstructure, mechanical and tribological properties. The results showed that the surface of the deposited films exhibited granular-like morphology, and the sp2 content, surface roughness increase with the increase of film thickness, leading to the lower of hardness and higher of the internal stress. Both of the friction curves obtained by nano-tribological tests and fretting wear experiments revealed a three-stage evolution tendency with the same wear mechanism for the first two stages. The intermediate thick GLC film had the lowest specific wear rate, whilst the fretting fatigue life increased with film thickness.

Effect of micro-arc oxidation on fretting wear behavior of zirconium alloy exposed to high temperature water

Flow-induced vibrations can result in fretting wear damage to the surfaces of clad fuel rods (tubes) against their supports in nuclear power plants. One possible solution to this problem is using oxide coatings. In this work, tangential fretting wear experiments were carried out in simulated primary cooling water such as that used in a pressurized water reactor (PWR) to study the effects of micro-arc oxidation (MAO) on the fretting wear behavior of a reactor-grade zirconium alloy known as ZIRLO™. The results indicated that the micro-arc oxidation improved the fretting wear resistance of the ZIRLO™ tube. The synergic effects of corrosion and mechanical wear on the fretting wear of the ZIRLO™ substrate and the MAO coating are discussed, and the role of the MAO coating in mitigating the fretting wear of zirconium alloy in high temperature water is revealed.

Characterization of fretting wear experiments on spline couplings by principal component analysis

Fretting wear is a quasi-static process in which repeated relative surface movement of components results in wear and fatigue. Fretting wear is quite significant in the case of spline couplings which are frequently used in the aircraft industry to transfer torque and power. Fretting wear depends on materials, pressure distribution, torque, rotational speeds, lubrication, surface finish, misalignment between spline shafts, etc. The presence of so many factors makes it difficult to conduct experiments for better models of fretting wear and it is the case whenever a mathematical model is sought from experimental data which is prone to noisy measurements, outliers and redundant variables. This work develops a principal component analysis based method, using a criterion which is insensitive to outliers, to realize a better design and interpret experiments on fretting wear. The proposed method can be extended to other cases too.

Effect of normal force on fretting wear behavior and mechanism of Alloy 690TT in high temperature water

Fretting wear experiments have been performed in high temperature water with a range of normal forces to investigate the wear behavior of Alloy 690TT tube sections oscillating against stainless steel Type 304 plates. Alloy 690TT is a Ni-based alloy containing Fe, Cr, and other minor additions. Results of tests conducted in an autoclave chamber in pressurized 288°C water, indicated that fretting wear processes mainly consisted of adhesive wear, abrasive wear, delamination, material transfer, and oxidation. As normal force increased, the initial contact area also increased, resulting in the increase of wear area as well as wear depth. Fretting wear promoted the oxidation of fresh material, and the mechanism corresponded in certain aspects to static oxidation. That is, the outermost surface layer consisted of an Fe-rich spinel, while Cr2O3 existed in the inner layer after fresh materials were exposed to the testing environment.