Wear Area Research Articles

Influence of Corrosion on Thermo-Mechanical Contact Fatigue in Rolling Conditions with Low Amplitude Sliding

The paper presents some aspects concerning mechanical contact fatigue and corrosion wear and the links of these two kinds of wear in the common deterioration of the contact layer. The surface state, for both presented areas, is analyzed using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) in order to confirm the double action of corrosion and wear during the experimental test. 2 and 3D insights were taken from the worn area, corrosion compounds were identified and analyzed. Linear and cyclic potentiometry were performed on the base materials after the OCP was established in salt solution. When the level of the thermal and the mechanical stress are located at the same depth under the contact surface the resulting stress is greater and has the opportunity to develop the first crack to the surface. The metallic material surface presents a double type of corrosion: one based on oxidation and the other one based on oxidation plus wear (tribo-corrosion), the difference is being given by the material quantity and type involved.

Effect of forward and reverse cutting on tool wear behavior in ultrasonic vibration-assisted milling of 3D needle-punched C/SiC composites

C/SiC composites have excellent mechanical properties such as high specific strength and high temperature resistance, and are widely used in aerospace fields. However, due to its special structure and material properties, the tool wear is severe when machining with conventional methods, and the processing quality is poor. The purpose of this paper is to reveal the progressive wear behavior, wear mechanism of the tool, and its effect on machining performance in conventional milling (CM) and ultrasonic vibration-assisted milling (UVM) of C/SiC composites under forward fiber cutting (FC) and reverse fiber cutting (RC). The material removal and heat transfer models were established, and the stress distribution characteristics of cutting -edge were analyzed by finite element method (FEM). Combined with the wear morphology, cutting heat, and cutting force, the tool wear behavior and mechanism in UVM and CM under FC and RC were studied, and their effects on machining quality were analyzed. The results show that there are great differences in heat transfer and removal process between FC and RC. In UVM, the introduction of ultrasonic vibration reduces the adhesion of fine chips, weakens the strong friction and scratching between the hard chips and the cutting -edge, and alleviates the tool wear. The flank wear VB and cutting -edge wear area WA in RC are larger than those in FC, the abrasive wear is intensified, the material even peeling under mechanical shock, and the adhesive wear is more serious. When the tool wear intensifies to a certain extent, the difference of the cutting process caused by mechanical anisotropy of C/SiC composites is weakened, and the surface micro-defects and surface roughness Sa change little under FC and RC. This research contributes to the realization of high-quality and low-cost processing of C/SiC composites.

Dramatic changes in water lubrication aroused by light

Light-controlled friction and lubrication has a wide prospect in industry and life. The friction coefficient of water lubrication between silicon nitride and titanium dioxide was found to be significantly changed by ultraviolet treatment from superlubricity to near lubrication failure. Under fully flooded conditions, the relative difference in wettability between wear and non-wear zone determined film formation of water lubrication, and its change after ultraviolet treatment aroused the failure of lubrication. While for the starved water lubrication, ultraviolet treatment slowed down the tribo-chemical reaction rate to form smaller particles on wear area, which was more conducive to lubrication and even reduced to superlubricity. Such enormous changes of water lubrication in macroscale may throw a new light on light-controlled friction and lubrication.

Probing the effect of displacement on electrical contact tribological behavior at the risk frequency of nuclear safety DCS equipment

Purpose This paper aims to study the tribological characteristics of the electrical contact system under different displacement amplitudes. Design/methodology/approach First, the risk frequency of real nuclear safety distributed control system (DCS) equipment is evaluated. Subsequently, a reciprocating friction test device which is characterized by a ball-on-flat configuration is established, and a series of current-carrying tribological tests are carried out at this risk frequency. Findings At risk frequency and larger displacement amplitude, the friction coefficient visibly rises. The reliability of the electrical contact system declines as amplitude increases. The wear morphology analysis shows that the wear rate increases significantly and the degree of interface wear intensifies at a larger amplitude. The wear area occupied by the third body layer increases sharply, and the appearance of plateaus on the surface leads to the increase of friction coefficient and contact resistance. EDS analysis suggests that oxygen elements progressively arise in the third layer as a result of increased air exposure brought on by larger displacement amplitude. Originality/value Results are significant for recognizing the tribological properties of electrical connectors in nuclear power control systems. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2024-0098/

Tool wear image segmentation algorithm based on K-means clustering

Abstract The existing tool wear region segmentation and detection methods make it difficult to achieve accurate detection of tool wear images under the conditions of noise interference. To further improve the detection efficiency and detection accuracy, combined with the characteristics of tool wear, this paper proposes a tool wear image segmentation algorithm based on K-means clustering to achieve accurate detection of tool wear images. Firstly, the acquired image is pre-processed to reduce the image processing computation and optimize the image, filter out the noise, and reduce the interference of the image. Then K-means clustering is used to cluster the surface features of the image, and then a threshold segmentation algorithm is used to locate the tool wear area and segment it out. The final experimental results show that the segmentation accuracy of this method is high and can be applied to tool wear area detection.

Estimating Wear Rate of Guide Vanes in High-Head Francis Turbines through Flow-Through Testing and DPM Simulation

Abstract The development of high-head water resources poses a significant concern due to hydro-abrasive erosion caused by entrained sediment particles. This issue is particularly prevalent in the muddy rivers of the Xinjiang region, China, where Francis turbines are commonly used. With increased soil erosion and rapid sediment transport, the erosion of Francis turbines, especially the guide vanes of high-head turbines, has become increasingly severe. The paper explores key factors that influence the erosion process caused by sediment-laden water. In addition to flow velocity and mud concentration, the properties of the sediment-laden water, such as hardness and size of sand particles, and the concentration ratio of sand particles with different hardness, also play a crucial role in the erosion process. The study is focused on analyzing the erosive effects of sediment-laden water on a high-head Francis turbine’s guide vane. The efficacy of the discrete phase model (DPM) as a simulation method for assessing wear on the guide vane is validated. This model helps analyze critical wear areas on the surface of the vane, enabling the identification of regions most severely affected by erosion due to sediment-laden water. By pinpointing these critical wear areas, the study provides valuable insights into the potential damage caused to the guide vane, thus contributing to better understanding and potential mitigation of erosion in similar turbine systems.

Effect of Si3N4 content on microstructure and frictional-wear properties of MoNbTaWTi refractory high entropy alloy composite coatings

To address the shortcomings of the Ti-6Al-4 V alloy, characterized by low surface hardness and inadequate friction and wear properties, a composite coating of in-situ TiN reinforced MoNbTaWTi refractory high-entropy alloy was developed using laser cladding technology on Ti-6Al-4 V substrate. The effects of different Si3N4 contents on coating organization and wear resistance are discussed. Analysis through X-ray diffractometry (XRD), scanning electron microscopy (SEM), and electron probe microanalysis (EPMA) revealed that the composite coating primarily consisted of the body-centered cubic (BCC) phase and an in-situ TiN enhanced phase. Notably, at a Si3N4 content of 2.0 wt%, the average microhardness at the coating's top surface reached 808.67 HV0.1, surpassing that of the substrate by 2.33 times. The friction coefficient was reduced to 0.3009, representing only 59.01 % of the Ti-6Al-4 V substrate. Furthermore, the wear weight loss measured at 0.4×10−2 mm3 was a mere 22.35 % of the Ti-6Al-4 V substrate, with the wear area accounting for only 0.27 % of the Ti-6Al-4 V substrate. Results demonstrated that utilizing the in-situ reaction between Ti element and Si3N4, the in-situ generated TiN reinforced phase significantly enhanced the hardness and wear resistance of the coating.

Intraoral Scanning for Monitoring Dental Wear and Its Risk Factors: A Prospective Study.

Dental wear arises from mechanical (attrition or abrasion) and chemical (erosion) factors. Despite its prevalence and clinical significance, accurately measuring and understanding its causes remain challenging in everyday practice. This one-year study with 39 participants involved comprehensive examinations and full-arch intraoral scans at the start and after 12 months. Volume loss exceeding 100 µ on each tooth's surfaces (buccal, lingual/palatine and incisal/occlusal) was measured by comparing three-dimensional scans from both time points. This study also assessed factors such as abrasion and erosion through clinical exams and questionnaires. There were no significant differences in dental wear in participants with sleep bruxism. However, noticeable wear occurred in the front teeth of those with waking bruxism and joint-related symptoms. Increased wear was associated with frequent consumption of acidic drinks, regular swimming, dry mouth, nocturnal drooling and heartburn, while no significant wear was found in patients with reflux. The used methodology proved effective in accurately assessing the progression of dental wear, which is important as many patients may initially be asymptomatic. The variability observed in dental wear patterns underscores the need to develop specific software applications that allow immediate and efficient comparison of wear areas based on extensive analysis of patient databases.

Optimization of Hydraulic Efficiency and Internal Flow Characteristics of a Multi-Stage Pump Using RBF Neural Network

In order to improve the hydraulic efficiency and internal flow pattern of a multi-stage pump under multiple flow conditions, an intelligent optimization design was proposed for its hydraulic components. Sensitivity analysis was used to select the key parameters influencing the hydraulic efficiency of a multi-stage pump. The optimal Latin hypercube sampling and non-dominated sorting genetic algorithm Ⅱ were employed to build a multi-objective optimization system. Moreover, a radial basis function neural network was adopted as the surrogate model of hydraulic efficiency. The research results showed that the impeller outlet width, impeller blade wrap angle, impeller outlet blade angle, and diffuser inlet width were the key factors affecting the hydraulic efficiency. The efficiency of the optimized model increased by 4.35% under the design condition and the matching of the internal flow between the optimized impeller and diffuser was significantly enhanced under the nominal condition. The improved flow pattern could be clearly observed in the flow passage of both the pump impeller and the diffuser. After optimization, the wear performance of the model was also improved compared to the original design. The wear area decreased in size and was distributed more evenly, resulting in a noticeable decrease in the maximum amount of wear.

A novel wear prediction method and wear characteristic analysis of piston/cylinder pair in axial piston pump

The wear of the piston/cylinder pair in the axial piston pump is a significant factor that adversely affects pump performance. To conduct a thorough investigation into the wear characteristics of the piston/cylinder pair, a dynamic model based on the equivalent load method is established. Then, a novel wear prediction method for the piston/cylinder pair is proposed by integrating the Archard wear model. The validity of the proposed method is confirmed through experimental verification. The results demonstrate that specific circumferential areas of the cylinder bore exhibit severe wear, and the distribution of these areas remains relatively stable over time. At the swash plate side, the most severe wear area along the circumference direction is concentrated in the range of approximately 200°–320°, which means the area that deviates from the extreme position in the radial direction of the pitch circle by a specific angle, with the deviation direction being opposite to the rotational speed. Conversely, at the valve plate side, the most severely worn circumferential area is situated in the range of about 0°–120°, which is opposite to the area at the swash plate side. The proposed wear prediction method offers improved computational efficiency, providing valuable support for analyzing the wear characteristics and failure mechanisms of piston pumps.

A new approach to identify wear regions on bearing surfaces of retrieved endoprostheses

Although total hip replacements (THR) can be considered one of the most successful implantable medical devices in history, wear remains the ultimate challenge in order to further increase clinical success. Wear assessment on retrieved implants is the most reliable way to perform research into failure mechanisms. Therefor the bearing surface of the explant is measured geometrically by coordinate measuring machine (CMM).Wear determination in geometrical data is carried out in 3 steps: (1) identifying the worn area, (2) reconstructing the pre-wear geometry and (3) quantify wear as the difference between worn area and pre-wear geometry. In previous studies, assumptions to pre-wear geometry had been made for wear determination (step 2) and the worn area was identified by deviations between measured data and assumed form. Thus, the original form of the retrieved endoprostheses, including form deviations due to the manufacturing process and implantation, was not considered which leads to uncertainties in the wear computed.This work introduces a method which allows to identify the wear area without making assumptions to the original form. Instead, the curvature of the bearing surface obtained by simple computations on the measurement data is analysed and the edge of the wear region is recognized by its deviation in curvature.The method is applied to a retrieved Metal-on-Metal prosthetic head and the results are compared to those of the well-known method introduced by Jaeger et al., in 2013. With the new approach the wear region is identified more accurately.

Boiling of Coolant Near the Cutting Edge in High Speed Machining of Difficult-to-Cut Materials

This study investigates film boiling of coolant as a cooling inhibitor in a narrow wedge-shaped space between the tool flank face and the machined surface of a workpiece, observed during high-speed turning of stainless steel SUS304 and nickel-based superalloy Inconel 718. The boiling, likely triggered by high surface temperatures at both the face and surface close to the cutting edge, impedes coolant access to the tool tip area and efficient cooling. Therefore, the impact of coolant pressure on the boiling zone size was initially explored across pressures ranging from 0.1 to 20 MPa. A burn mark band due to coolant boiling, distinctly visible on the flank face of an insert with a yellow hard coating, expanded over cutting time. The film boiling area width, or the distance from the flank wear area to the band, decreased with increasing coolant pressure, reflecting the enhanced cooling ability and tool life with high-pressure coolant. Applying Boyle–Charles’ law to film boiling indicated that vapor pressure was directly related to coolant velocity rather than pressure. In contrast, the boiling area width increased with increasing cutting speed.

Paedodontic preformed crowns in primary teeth and relative degree of dental wear.

Prosthetic rehabilitation of deciduous teeth in paediatric age using pre-formed crowns has been considered one of the best methods of dental restoration since their introduction. Their main advantages are related to durability, longevity and a low rate of recurrent cavities. Since stainless steel crowns do not coincide with aesthetic needs of parents and patients, preformed paedodontic crowns made of zirconia and nano-hybrid composite was introduced. The aim of the study is to evaluate the degree of wear on the enamel and on themselves of the different paedodontic crowns. Nine bovine teeth and nine paedodontic crowns for deciduous molars were selected for the study, three of which in zirconia, three in nano-hybrid composite and three in stainless steel. Wear test was carried out on the Rtech™ Instruments tribometer applying a force of 50 N. After that, both the bovine teeth and the paedodontic crowns were observed using a stereo microscope (Zeiss Stemi C-500) and a scanning electron microscope (SEM, Cambridge Stereoscan 440). The areas of wear were calculated with a software [ImageJ, version 1x, Wayne Rasband, Maryland, USA]. Pre-formed paediatric crowns in zirconia, nano-hybrid composite and stainless steel are a valid aid for the restoration of deciduous teeth and do not compromise the physiological wear characteristic of the phases of the dental exchange. The stainless steel crown is preferable for the restorations in the posterior sectors as its behaviour is the most similar to that of a natural tooth. Zirconia and nano-hybrid composite crowns showed an inversely proportional behaviour between their wear volume and that of the opposing tooth.

Three-dimensional profilometry for tool wear area using modulation-based structured illumination microscopy

A new approach named modulation-based structured-illumination microscopy (MSIM) is presented in this paper to reconstruct the three-dimensional (3D) topography of the tooltip, which can be used to evaluate the degree of wear. In MSIM, the modulation estimation of the reflected patterns characterizes the surface profile. This technique can reconstruct the 3D profile precisely and something that conventional computer vision and imaging analysis cannot achieve. Importantly, an ordinary objective lens is used in the measurement system to take the image of the sample. So, the measurement system is simple and cheap. The theoretical analysis and experiments conducted on the tooltip are presented. The measurement repeatability can reach 500 nm. This method holds promise for applications in tool wear monitoring, wear mechanism analysis, and micromachining.

Study of tribological performance and corrosion resistance of aluminum alloy 6063 composites enhanced with a combination of silicon carbide and tungsten disulfide particles

This research explores the effects of wear on a 6063 aluminum alloy matrix combined with silicon carbide (SiC) and tungsten disulfide (WS2) particulates. Dry friction wear tests were conducted on three materials: pure 6063 aluminum alloy, a composite with 4 wt% SiC and 4 wt% WS2 reinforcement, and another composite with 6 wt% SiC and 4 wt% WS2 reinforcement. These materials were tested against AISI410 stainless steel discs under varying loads (10N, 20N, and 30N) and sliding rates (0.5, 1.0, and 1.5 ms−1) following a Taguchi L27 orthogonal experimental plan. Main effect graphs (S/N ratios) and ANOVA analysis were utilized to determine optimal parameter combinations, and confirmation tests were carried out to validate the Taguchi results. Scanning electron microscope (SEM) images of wear areas showed that incorporating SiC and WS2 significantly enhanced the wear resistance of the aluminum alloy. This indicates that incorporating SiC and WS2 reinforcement has the potential to enhance the wear resistance of aluminum alloys, making them suitable for applications such as piston rings in internal combustion engines, which is in line with the requirements of engine performance. Furthermore, potentiodynamic polarization studies evaluated the corrosion resistance of the Metal Matrix Composites AA6063 in 3.5% NaCl. Results indicated that the AA6063 + 6 wt% SiC + 4 wt% WS2 composite exhibited superior corrosion resistance compared to AA6063 alone.

Tribo-corrosion-fatigue behaviors of the parallel wires of main cable in the suspension bridge

The suspension bridge in service is subjected to the coupling effects of dead load, vehicle load, wind load and corrosive environment. These factors cause the tribo-corrosion-fatigue behaviors of parallel steel wires of main cable, which seriously affect the load-bearing safety of the main cable. Therefore, it is of great significance to investigate tribo-corrosion-fatigue behaviors of steel wires and the saddle materials. The self-made test rig was developed to carry out tribo-corrosion-fatigue tests between the parallel steel wires, and between the steel wire and saddle groove. Tribo-corrosion-fatigue behaviors (friction coefficient, wear profile, failure area, wear mechanism and wear coefficient) of main cable wires was revealed by high speed digital microscope and scanning electron microscope. The results show that the friction coefficient shows a trend of rapid increase – decrease – increase – stabilization. It decreases with increasing contact load as compared to an increase with increasing fatigue load. The wear width and depth both increase nearly linearly with increasing cycles, while the failure area increases nearly parabolically. As the contact load and fatigue load increase, the wear width and depth increase, and the corrosion of wear area is more obvious. The wear coefficient decreases first and then increases with the increase of cycles. The wear mechanisms are mainly adhesive wear, abrasive wear, fatigue wear and corrosion wear. The increase of contact load and fatigue load promotes the wear deterioration behaviors of cable wires. The results have fundamental significance to ensure the load-bearing safety of the main cable and improve the service safety of the suspension bridge.

Influence of tool nose angle on cutting performance in hot machining of Inconel 718

Superalloy Inconel718 is an important material for aircraft preparation because of its excellent performance at high temperatures. However, when cutting Inconel718, a large amount of cutting heat will be generated, resulting in excessive tool temperature and serious wear, which accelerates the tool failure. In order to solve this problem, the influence of tool angle on the process of thermal aided machining was studied by simulation model combined with thermal aided machining technology. During the cutting process, the workpiece preheating temperature rises from room temperature 20° C to 500° C, the front tool angle range is − 5° to 10°, and the rear tool angle range is 4° to 16°. By analyzing various parameters, it was found that a smaller tool rake angle can effectively reduce the tool temperature. Additionally, a flank angle of around 12° was found to decrease the maximum wear area of the tool by approximately 10.5%. Moreover, it was observed that implementing heat-assisted machining can result in a significant reduction of tool temperature by 11.1%, as well as a decrease in cutting force ranging from 18 to 22%, particularly at temperatures exceeding 500 °C.

A Study of Water-Based Nanolubricants Using Hexagonal Boron Nitride (hBN)-Based Nanocomposites as Lubricant Additives

An Rtec ball-on-disk tribometer was used to investigate the tribological performance of the synthesised water-based nanolubricants containing hBN/TiO2 nanocomposite at room temperature. The water-based nanolubricants with different concentrations were prepared by adding glycerol and sodium dodecyl benzene sulfonate (SDBS) under ultrasonication. These as-prepared nanolubricants demonstrated exceptional dispersion stability for 7 days without distinct sedimentation. The results indicate that the water-based nanolubricants with an overall concentration of 1.0 wt% at different ratios (hBN: TiO2 = (1:0), (0.7:0.3), (0.5:0.5), (0.3:0.7), (0:1)) can effectively reduce the coefficient of friction (COF) and the wear of the ball and disk. In particular, the water-based nanolubricant containing 0.5 wt% hBN and 0.5 wt% TiO2 exhibited the best tribological performance, leading to a significant reduction in COF up to 70%, and decreased the wear area of the ball and disk by up to 79.57% and 60.40%, respectively, compared to those obtained using distilled water. The lubrication mechanisms were mainly attributed to the formation of a protective film, and the mending, polishing, rolling, and synergistic effects of the hBN nanosheets and TiO2 nanoparticles.

Investigation of friction and wear behavior of titanium alloy-diamond based on the morphology evolution of single abrasive clusters

This study investigates the wear mechanism of single diamond clusters during flexible scratching of titanium alloys. High-temperature rotary friction and wear tests were conducted using a flexible abrasive tool with bonded single diamond clusters. The study examined the impact of normal loads, rotation speeds, and temperatures on cutting ability and wear in titanium alloys. The percentage of abraded area in the annular cross-section was proposed as an index for evaluating diamond wear. The results indicate that the primary factors affecting diamond cluster wear are normal load and temperature, while friction speed has a relatively minor impact. At a 2 N load, the abrasive grains exhibited abrasive blunt wear without causing obvious damage to the titanium alloy surface. However, at a 4 N load and a temperature of 110 °C, adhesive wear became dominant, resulting in localized damage and oxidative wear on the diamonds. The annular cross-section abrasive wear profile revealed a nearly 30% increase in abrasive grain wear area as the normal load and temperature increased. This study aims to improve understanding of the abrasive grain wear at various stages and lays the foundations for grinding and polishing large-sized, high-precision parts.

Study on High-Temperature, Ultra-Low Wear Behaviors of Ti6Al4V Alloy with Thermal Oxidation Treatment

Thermal oxidation (TO) is a simple and economical way to enhance the wear resistance of the Ti6Al4V alloy. The TO temperature has a very important effect on the tribological properties of the TiO2 layer formed. However, the impact of the oxidation temperature on the high-temperature tribological behavior of a TO-treated Ti6Al4V alloy is not clear. Therefore, the Ti6Al4V alloy was oxidized at 400 °C, 600 °C, and 700 °C for 36 h, and the sliding friction experiments were conducted at room temperature (RT) and 400 °C with a Si3N4 ball as the counter body to comparatively study the effect of the oxidation temperature on the high-temperature friction behavior of the TO-treated Ti6Al4V alloy. The results show that the TO treatment can effectively improve the wear resistance of the samples at both room and high temperatures. Among them, the oxidation-treated samples at 700 °C show the best wear resistance, with a reduction of 92.6% at high temperatures; the amount of wear loss at room temperature was so small that it was almost incalculable. At room temperature, the friction surface formed uneven agglomerate formations, resulting in an elevated coefficient of friction (CoF) compared to the untreated samples. At a high temperature, however, the CoF is reduced compared to the untreated samples due to the formation of a homogeneous transfer film in the wear area that is caused by the interaction of Si3N4 and oxygen.