Fretting Wear Process Research Articles

Exploring ambient and elevated temperature fretting wear behavior of laser-cladding (FeCrCoNi)84AlxNby high-entropy alloy coatings

In this work, (FeCrCoNi)84AlxNby (x = 12, 8, 4 and y = 4, 8, 12 (at. %)) high-entropy alloy (HEA) coatings were successfully deposited on 316 stainless steel via laser cladding (LC). FCC/BCC + Laves structure was introduced into FeCrCoNi HEA system by designing different Al/Nb ratios, aiming to improve the fretting wear resistance. The phase constituents, microstructure, and fretting wear resistance of (FeCrCoNi)84AlxNby HEA coatings at ambient temperature and 285 °C were respectively analyzed. Results confirmed that the microstructure of three HEA coatings displayed the interdendritic (IR) - dendritic (DR) structure. With the Al/Nb ratio decreased from 3/1 to 1/3, the phase constituents of HEA coatings transformed from the BCC solution to FCC solution and Laves phase, and the content of the Laves phase gradually increased. Moreover, the average grain size decreased from 16.9 μm to 4.6 μm, while the average geometrically necessary dislocations (GNDs) density increased from 1.842 × 1010 m−2 to 2.821 × 1010 m−2. The microhardness of the HEA coatings was improved from 210 HV0.2 to 361–647 HV0.2 compared with that of the substrate. The decrement of Al/Nb ratio improved the fretting wear resistance of HEA coatings both at ambient temperature and 285 °C, especially at 285 °C. The wear volume decreased from 0.8 × 105 μm3 to 0.39 × 105 μm3 and the fretting wear mechanism changed from severe fatigue wear to slight abrasive wear at 285 °C. In the Al4Nb12 HEA coating, the soft structure (FCC) and the hard structure (Laves) were combined into a wear-resistant skeleton, and the Laves structure was massively distributed along the FCC phase to prevent the FCC phase from further slipping in the fretting wear process, which in turn minimizes the fretting damage. The present work provides a theoretical basis for the related research on the fretting wear characteristics of laser cladding HEA coatings.

Effect of Low-Temperature Plasma Carburization on Fretting Wear Behavior of AISI 316L Stainless Steel

AISI 316L stainless steel has received considerable attention as a common material for key ball valve components; however, its properties cannot be improved through traditional phase transformation, and fretting wears the contact interface between valve parts. A carburized layer was prepared on the surface of AISI 316L stainless steel by using double-glow low-temperature plasma carburization technology. This study reveals the effect of double-glow low-temperature plasma carburization technology on the fretting wear mechanism of AISI 316L steel under different normal loads and displacements. The fretting wear behavior and energy dissipation of the AISI 316L steel and the carburized layer were studied on an SRV-V fretting friction and wear machine with ball–plane contact. The wear mark morphology was analyzed by using scanning electron microscopy (SEM), the phase structure of the carburized layer was characterized with X-ray diffractometry (XRD), and the wear profile and wear volume were evaluated with laser confocal microscopy. The carburized layer contains a single Sc phase, a uniform and dense structure, and a metallurgically combined matrix. After plasma carburizing, the sample exhibited a maximum surface hardness of 897 ± 18 HV0.2, which is approximately four times higher than that of the matrix (273 ± 33 HV0.2). Moreover, the surface roughness was approximately doubled. The wear depth, wear rate, and frictional dissipation energy coefficient of the carburized layer were significantly reduced by up to approximately an order of magnitude compared with the matrix, while the wear resistance and fretting wear stability of the carburized layer were significantly improved. Under different load conditions, the wear mechanism of the AISI 316L steel changed from adhesive wear and abrasive wear to adhesive wear, fatigue delamination, and abrasive wear. Meanwhile, the wear mechanism of the carburized layer changed from adhesive wear to adhesive wear and fatigue delamination, accompanied by a furrowing effect. Under variable displacement conditions, both the AISI 316L steel and carburized layer mainly exhibited adhesive wear and fatigue peeling. Oxygen elements accumulated in the wear marks of the AISI 316L steel and carburized layer, indicating oxidative wear. The fretting wear properties of the AISI 316L steel and carburized layer were determined using the coupled competition between mechanical factors and thermochemical factors. Low-temperature plasma carburization technology improved the stability of the fretting wear process and changed the fretting regime of the AISI 316L steel and could be considered as anti-wearing coatings of ball valves.

Atomic-scale study of linear reciprocating friction of TCP/γ phase in nickel-based single crystal alloy

In order to systematically investigate the role of TCP (topologically close-packed) phases in the fretting wear process of nickel-based single crystal alloys (NBSC), this study employed molecular dynamics to conduct comparative analyses of mechanical properties, atomic displacements, wear depth, defects, dislocation density, and the influence of temperature under constant load on the friction process in material wear. The research revealed that during the repetitive friction process, the friction force exhibited a peak at the extreme positions of reciprocating friction on the workpieces, and this peak increased with the number of friction cycles. The dislocation density in the worn area increased, resulting in hardening, and the removal rate of material decreased. At the initial stages of friction, the presence of interfaces notably hindered the transfer of temperature, defects, and atomic displacements in the workpiece, and this inhibitory effect weakened with an increasing number of friction cycles. The TCP phases experienced stratification due to the overall deformation they underwent. Furthermore, as the relaxation temperature increased, the workpiece exhibited enhanced plastic deformation capacity, an increase in dislocation density, and adhesion between abrasive particles and the grinding ball occurred.

Three-dimensional finite element simulations of fretting wear in steel wires used in coal mine hoisting system

Fretting wear is a surface damage phenomenon that occurs at contacting surfaces due to the micro relative movements of contacting surfaces. It is not easy to consider the parametric study of this phenomenon by experimental methods. For example, it is not straightforward to measure the contact stresses and wear scars under different loading conditions during the experimental process. Furthermore, the experimental process is economically expensive and time-consuming. In this paper, the fretting wear behavior of steel wire ropes used in coal mine technology is numerically investigated and the results are compared with experimental data. The numerical results of the effect of contact parameters on the fretting wear process during the fretting cycles are also analyzed. For this purpose, a three-dimensional Finite Element (FE) model is created and validated with an analytical solution. The simulations of the FE model are performed using the commercially available FE tool ABAQUS combined with subroutine UMESHMOTION. The available experimental data of fretted wires in the form of coefficient of friction is used to define the interaction between the contacting surfaces of FE model and the maximum wear depth is used to validate the wear depth obtained through the numerical model. A convergence study is also carried out to select the most suitable parameters for the simulation of contacting surfaces. After the validation of the FE model, the effect of fretting amplitude, contact load and different contacting angles of fretted wires on wear characteristics is considered. The results show that higher fretting amplitude and contact load have a significant effect on wear profile, wear depth, and wear scar. The maximum wear depth, wear depth increasing rate and contact stress decreasing rate is high for higher contact angles compared to smaller contact angles.

Fretting wear behavior of Inconel 718 alloy manufactured by DED and treated by UNSM

Alloy 718 is commonly used in the maritime and aerospace industries due to its strength and durability, particularly in engine rotating components such as disks, fan blades, and high-pressure compressors. As a new type of 3D printing technology, directed energy deposition (DED) can employ lasers to melt metal powders or wires to fabricate arbitrary-shaped workpieces directly from customized data, thereby making machining more synergistic and intuitive. However, the surface properties of the DED-printed alloy 718 samples, such as surface roughness and wear resistance, are typically subpar. By introducing severe plastic deformation to the near-surface, ultrasonic nanocrystal surface modification (UNSM) can be used as a post-processing method and results in altered properties. The uniaxial tensile test reveals that the UNSM-treated alloy 718 exhibits a higher mechanical property. Moreover, using a fretting test rig in accordance with the cylinder-on-plane agreement, a higher wear resistance for UNSM-treated alloy 718 is observed. This study employs the finite element method to fully comprehend the effect of UNSM on wear performance. The fretting wear process of Inconel 718 alloy is established using an energy-based finite element model. Considering the severe practical scenarios, the Johnson–Cook constitutive model is implemented, with the linear isotropic hardening model capturing the plastic behavior. In comparison to experimental measurements, the finite element results demonstrate unprecedented wear loss consistency with an error of less than 2%. Therefore, we conclude that the finite element model built in this study exhibits a high accuracy and can be used to analyze the effect of UNSM on fretting wear behavior. According to finite element analysis, as the normal load increases, the improvement in wear resistance induced by UNSM decreases. Given that the finite element model is based on the energy method, the effects of coefficient of friction (COF) and wear coefficient modified by UNSM are investigated separately. According to the findings, the UNSM-modified COF and wear coefficient play a significant role in determining the wear characteristics. Due to the removal of a substantial amount of material from the central area of the alloy 718 surface by wear, it is also possible to observe that severe plastic strains are primarily concentrated at the edges of the wear scars.

Wear behaviour of AlCN/AlC and FeCrN coatings developed on alloy steel

ABSTRACT The fretting wear and adhesive wear resistance of Al and Fe-based thin solid films deposited onto MDN121 steel are studied. Plasma-assisted cathodic arc evaporation technique (P-CAE) is used to develop AlCN/AlC and FeCrN monolayer coatings. The coatings and wear tracks are characterised by FESEM-EDS, nanoindentation, Raman spectroscopy, optical profiler, and confocal microscope. The results reveal that during fretting and adhesive wear, tracks are investigated using confocal microscopy and electron microscopy. When fretting wear occurs, the Coefficient of Friction (COF) dramatically decreases for AlCN/AlC thin solid films by 48.65% and for FeCrN thin solid films by 62.16% when compared to the substrate. FeCrN coating exhibits lower volumetric wear loss than AlCN/AlC coating. The wear surface morphology of both monolayer coverings against galling failure in the substrate exposes the abrasive form of the fretting wear process. Thin solid films of AlCN/AlC and FeCrN experience a COF reduction during adhesive wear of 40.89% and 56.22%, respectively, in comparison to the substrate. The FeCrN monolayer coating exhibits low friction and wear rate compared to AlCN/AlC monolayer coating.

Carbon fiber modified by attapulgite for preparing ultra‐high molecular weight polyethylene composite with enhanced thermal, mechanical, and tribological properties

AbstractThe attapulgite nanofibers (ATP) were grafted on the surface of carbon fibers (CF) by polyetherimide (PEI) with long chain to reinforce the thermal, mechanical properties, and fretting wear resistance of ultra‐high molecular weight polyethylene. The results showed that the surface roughness of CF modified by ATP nanofibers were highly increased. Meanwhile, the thermal, mechanical, and tribological properties of the ATP‐PEI‐CF/UPE composite were significantly improved, especially the enhancement in heat distortion temperature, compressive modulus, and wear resistance. The improvement mechanisms of the corresponding properties were mainly attributed to the increase of mechanical interlocking of the matrix and the hybrid fillers, which could not only transfer the load and heat applied to the matrix to the fibers, but also impede the friction damage of the matrix during fretting wear process.

Effect of ultrasonic surface rolling process on the high temperature fretting wear behavior of Inconel 690 alloy

Inconel 690 alloy is widely used in nuclear steam generator tubes, which always suffer from various complex fretting wear behaviors during their service period. This study aims to investigate the effect of the ultrasonic surface rolling process (USRP) at different static pressures on the sliding fretting wear behavior of Inconel 690 alloy at room and 300 °C air temperature environments. Results indicate that the grains in the alloy surface layer are refined after treatment through the USRP, improving some of its surface mechanical properties. The fretting wear resistance of Inconel 690 alloy is also enhanced, and the higher static pressure is, the more obviously the strength effect would be. In addition, the extent of the fretting wear at 300 °C is less than that at room temperature. Furthermore, the abrasive, delamination, and wear oxidation mechanisms can be observed in all test samples during the entire fretting wear process.

Time-dependent reliability and optimal design of scraper chains based on fretting wear process

PurposeThis paper aims to present a dynamic reliability model of scraper chains based on the fretting wear process and propose a reasonable structural optimization method.Design/methodology/approachFirst, the dynamic tension of the scraper chain is modeled by considering the polygon effect of the scraper conveyor. Then, the numerical wear model of the scraper chain is established based on the tangential and radial fretting wear modes. The scraper chain wear process is introduced based on the diameter wear rate. Furthermore, the time-dependent reliability of scraper chains based on the fretting wear process is addressed by the third-moment saddlepoint approximation (TMSA) method. Finally, the scraper chain is optimized based on the reliability optimization design theory.FindingsThere is a correlation between the wear and the dynamic tension of the scraper conveyor. The unit sliding distance of fretting wear is affected by the dynamic tension of the scraper conveyor. The reliability estimation of the scraper chain with incomplete probability information is achieved by using the TMSA for the method needs only the first three statistical moments of the state variable. From the perspective of the chain drive system, the reliability-based optimal design of the scraper chain can effectively extend its service life and reduce its linear density.Originality/valueThe innovation of the work is that the physical model of the scraper chain wear is established based on the dynamic analysis of the scraper conveyor. And based on the physical model of wear, the time-dependent reliability and optimal design of scraper chains are carried out.

Investigation on fretting wear behavior of 2.25Cr–1Mo tube in water at various temperatures

Heat transfer tubes are subjected to cyclic and direct contact under high temperature liquid conditions due to flow-induced vibration. The influence of water temperatures (25, 60, and 95 °C) and loads (10, 20, and 30 N) on the fretting wear behavior of 2.25Cr–1Mo tube against Gr5C12 rod was investigated. Results indicate that the fretting regime changes from gross slip to partial slip as the load increases from 10 N to 30 N. The fretting regime remains unchanged as the water temperature increases from 25 °C to 95 °C. The fretting regime is more related to load than water temperature, implying that the water temperature and load play different roles in the fretting wear process. The coefficient of friction (COF), wear morphology, wear volume, and wear rate show an evident dependence on load and water temperature, while the COF has a significant relationship with the load. The effect of micro-pitting may be ignored due to the material removal from the original surface and formation of wear debris layer (WDL) in the gross slip regime.

Coupling Fractal Model for Fretting Wear on Rough Contact Surfaces

Abstract In this paper, a fretting damage model based on fractal theory is proposed. The Weierstrass–Mandelbrot function of fractal theory is used to represent the rough contact surface, and a corresponding contact parameter analysis method is also established. Based on neural network algorithm, the values of fractal parameters are fitted, and the fitting accuracy has been greatly improved compared with traditional methods. According to the fractal parameters of the actual surface, the fretting wear process of the rough contact surface is analyzed based on theory of adhesive and three-body abrasive wear. A generic program for the analysis of three-dimensional fretting wear problems is also proposed. Compared with material tests, the prediction error of the fretting wear simulation model is 13.4% for wear depth and 16.7% and 3.9% for width and length of wear scar in stable wear stage. The prediction results show that the model can be applied to the prediction of the actual three-dimensional fretting wear model.

Fretting wear mechanism of plasma-sprayed CuNiIn coating on Ti-6Al-4V substrate under plane/plane contact

The fretting wear mechanism of plasma-sprayed CuNiIn coating on Ti-6Al-4V substrate under plane/plane contact conditions was investigated systematically using a bench level test. The obtained experimental results showed that the fretting wear mechanism of the CuNiIn coating can be divided into three stages: (I) In the initial stage, the asperities on the rough surface were flattened to form debris and fill the nearby pits. The contact surface gradually flattened, which was accompanied by slight abrasive wear. (II) With increasing number of fretting cycles, the fretting wear process of the CuNiIn coating entered the delamination wear stage. Under the action of alternating shear loads, the lamellar structure and pores in the CuNiIn coating rapidly cracked and propagated to the surface. In addition, some fatigue cracks propagated into the matrix along the direction of maximum shear stress. (III) Eventually, the CuNiIn coating entered a stable wear state under the lubrication of a third body, which was accompanied by local delamination. The lamellar structure greatly enhanced the fretting wear resistance of the CuNiIn coating. In the process of fretting wear, the lamellar structure of the CuNiIn coating effectively hindered fatigue crack growth, guided crack deflection along the lamellar interface, and induced crack bifurcation. In addition, the pores can blunt the crack tip. • A new self-balancing device was developed to improve geometrical adaptation of friction pairs with plane/plane contact. • The fretting wear resistance of CuNiIn coating was better than that of Ti-6Al-4V. • The wear rate of the CuNiIn coating was non-monotonic with increasing number of cycles. • The lamellar structure of CuNiIn coating was conducive to delamination wear. • The lamellar structure of CuNiIn coating could induce crack deflection, stop crack propagation, and guide crack bifurcation.

Effects of fretting wear process on fatigue crack propagation and life assessment

This paper proposes a new methodology for fretting fatigue life assessment. It uses a combination of multiaxial fatigue criteria, the theory of critical distances and a node-displacement wear algorithm to account for the initiation life under fretting. Further, the extended finite element method is considered to compute the propagation life. A new method is also introduced to predict the crack propagation path under nonproportional loading conditions. To validate the analysis, available fretting fatigue data using an Al 2024-T3 alloy was considered. All the total lives estimated by the proposed approach fell within a scatter band 2, with an error between 11% and −39%. An analysis of the energy dissipated on the contact surface was performed and showed that for certain cases the inclusion of wear in the modeling of the problem is indeed essential to obtain more accurate fretting fatigue life assessments.

The Evolution of Fretting Wear Behavior and Damage Mechanism in Alloy 690TT with Cycle Number.

The evolution of fretting wear behavior and damage mechanism in Alloy 690TT with cycle number was investigated via laser scanning confocal microscopy (LSCM), scanning electron microscopy (SEM), focus ion beam (FIB), and transmission electron microscopy (TEM). The results showed that the fretting running status underwent a transition from partial slip and mixed stick-slip to final gross slip with the transformation of Ft–D curves from the ellipse to the parallelogram. The coefficient of friction (COF) experienced three drops throughout the fretting process, which indicated the transformation from high-friction wear to low-friction wear. The first drop was due to the transition from two-body to three-body contact. The second and third drops were mainly related to the evolution of the glaze layer from a localized distribution to completely covering the whole contact surface. The competition between fretting induced fatigue cracking (FIF) and fretting induced wear (FIW) ran through the entire fretting wear process. Before the 1.2 × 104th cycle, the fatigue crack growth was faster than wear, and FIF won the competition. As the fretting cycle continued to increase, the wear velocity was obviously faster than that of FIF, which indicated that FIW defeated FIF. The tribologically transformed structure (TTS) participated in the competition between FIF and FIW. The gain boundaries and dislocations in the TTS were a suitable pathway for crack initiation and propagation and oxygen permeation.

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.

Multiscale Analysis of the Effect of Debris on Fretting Wear Process Using a Semi-Concurrent Method

Fretting wear is a phenomenon, in which wear happens between two oscillatory moving contact surfaces in microscale amplitude. In this paper, the effect of debris between pad and specimen is analyzed by using a semi-concurrent multiscale method. Firstly, the macroscale fretting wear model is performed. Secondly, the part with the wear profile is imported from the macroscale model to a microscale model after running in stage. Thirdly, an effective pad's radius is extracted by analyzing the contact pressure in order to take into account the effect of the debris. Finally, the effective radius is up-scaled from the microscale model to the macroscale model, which is used after running in stage. In this way, the effect of debris is considered by changing the radius of the pad in the macroscale model. Due to the smaller number of elements in the microscale model compared with the macroscale model containing the debris layer, the semi-concurrent method proposed in this paper is more computationally efficient. Moreover, the results of this semi-concurrent method show a better agreement with experimental data, compared to the results of the model ignoring the effect of debris.

Fretting wear between Alloy 690 and 405 stainless steel in high temperature pressurized water with different normal force and displacement

As fretting wear has become one of the main failure mode of Alloy 690 tube in steam generators and is significantly affected by normal force and displacement, the fretting wear behavior of Alloy 690 with different normal force and displacement is studied in high temperature pressurized water. The coefficient of friction, wear volume and maximum wear depth decrease with the increasing of the normal force, while they increase with the increasing of displacement. In addition, the wear mechanism and wear damage are also significantly affected by the applied normal force and displacement. Wear coefficient and energy wear coefficient are calculated respectively. Energy wear coefficient may be a more precise parameter than wear coefficient to describe the fretting wear process.

The formation of a cobalt-based glaze layer at high temperature: A layered structure

The purpose of this study is to investigate the protective glaze layer structure formed during high temperature fretting wear process. The studied material is a cobalt-based alloy with a Cr-Ni-W solid solution (HS25) fretted against an alumina sample. It appears that a protective third body is spontaneously created at the interface for temperatures above 400 °C. The excellent tribological properties of the glaze layer leads to a stabilized friction coefficient of 0.3 and a quasi no-wear regime.Microstructure observations at the micro- and nanoscale were performed and revealed that the high temperature glaze layer is not homogeneous but rather composed of three layers with different grain sizes and chemical compositions. The investigations show that the effective glaze layer, the layer able to resist to fretting wear, is a thin layer made of nanocrystalline cobalt oxides. However, the chemical analysis reveals that before the formation of the effective glaze layer, the interface displays a high content of chromium oxides. Hence, a chemical segregation happens leading to the formation of a cobalt-rich effective glaze layer on the top of the former chromium-rich layer. In the light of these results, a chemical mechanism involving the consumption of chromium during the running-in wear stage is proposed to describe the glaze layer formation.

Analysis of the application of ZrN coatings for the mitigation of the development of fretting wear processes at the surfaces of push fit joint elements

The purpose of this article is to assess the influence of a ZrN coating on the development of fretting wear in a model of a wheel/axle push fit joint in a rail vehicle. The examinations of the fretting wear process in rail vehicle wheel sets were conducted on two groups of models consisting of a shaft and sleeve connected by means of a push-fit joint, in compliance with the rules for the representation of the real condition. Wear tests of a joint loaded with a vertical force were conducted on a fatigue testing machine permitting oscillatory tangential displacement, which is responsible for the development of fretting wear. Uncoated shafts were the first model, and shafts coated with a ZrN coating were the second one. The tolerance was 0.02 mm, the model loading force was 550 N and the number of fatigue cycles was 7 × 106. The destruction of models was evaluated in, for example, the computer image analysis process with the use of the Image Pro Plus 7.0 software. Macroscopic observations showed wear traces for both model groups. In the first group, wear traces were observed on either side of the axle seat, and those traces had the form of a 2–3 mm wide ring comprising the entire shaft circumference. The random location of the traces of wear was observed in the second model. The microscopic observations of the destruction areas demonstrated mainly the presence of material build-ups, the local surface abrasion and micropits. The analysis of the chemical composition of material build-ups showed the presence of iron and oxygen, a fact which confirms the shearing of the microirregularities of the sleeve top layer. Plastically deformed material build-ups become oxidised, hence the brown colour of the worn-out areas can be observed at the sample surface during macroscopic observations. The significant mitigation of fretting wear on samples with ZrN coatings has been demonstrated. This shows the need for fretting wear tests to be performed on a real object to confirm the scale of improvement of the life of forced-in joints, thus contributing to the higher reliability of rail vehicle wheel sets.

The Influence of Assembly Force on the Material Loss at the Metallic Head-Neck Junction of Hip Implants Subjected to Cyclic Fretting Wear

The impaction force required to assemble the head and stem components of hip implants is proven to play a major role in the mechanics of the taper junction. However, it is not clear if the assembly force could have an effect on fretting wear, which normally occurs at the junction. In this study, an adaptive finite element model was developed for a CoCr/CoCr head-neck junction with an angular mismatch of 0.01° in order to simulate the fretting wear process and predict the material loss under various assembly forces and over a high number of gait cycles. The junction was assembled with 2, 3, 4, and 5 kN and then subjected to 1,025,000 cycles of normal walking gait loading. The findings showed that material removal due to fretting wear increased when raising the assembly force. High assembly forces induced greater contact pressures over larger contact regions at the interface, which, in turn, resulted in more material loss and wear damage to the surface when compared to lower assembly forces. Although a high assembly force (greater than 4 kN) can further improve the initial strength and stability of the taper junction, it appears that it also increases the degree of fretting wear. Further studies are needed to investigate the assembly force in the other taper designs, angular mismatches, and material combinations.