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Gas metal arc welding (GMAW) integrated wire arc additive manufacturing (WAAM) depicts non-uniform layers, spatter, thermal distortions, metal overflow, and mechanical anisotropy. The prime cause for these issues is improper thermal energy management due to the current controlled wire feeding mechanism. Here, an autonomous wire feed system (AWFS) has been designed and integrated into the GMAW-WAAM to eliminate such issues. It fine-tunes the wire feed speed (WFS) and maintains a steady flow of arc current. With this developed system, initially, twenty single beads are deposited using ER70S-6 feedstock under different conditions of welding voltage (U), travel speed (TS), and WFS. Later on, an optimum deposit condition has been formulated using response surface methodology-RSM (U ≈ 21.7 V, TS ≈ 8.6%, and WFS ≈ 2.7 m/min). Under this deposit condition, thin-layered parts are manufactured, where inter-layer dwell time (IDT) is only varied (from 2 to 4 min) to illustrate its significance over metallographic and mechanical performances. It is observed that with increasing IDTs, the morphological attributes of the deposit are improved (straight side wall with low surface waviness) with a reduction in grain size that further boosts the hardness and mechanical performances (increased strength and wear resistance). The occurrence of compressive residual stress could additionally support the enhancements in mechanical strength. In addition to the improvements in mechanical performances, the anisotropy in mechanical strength was also reduced (< 5%). Moreover, bulk texture analysis ensures similar fiber texture evolutions along different deposit sections with a least variation in the texture intensity, which point towards isotropicity in the as-fabricated part. [ABSTRACT FROM AUTHOR]

A submersible sewage pump is designed for conveying solid–liquid two-phase media containing sewage, waste, and fiber components, through its small and compact design and its excellent anti-winding and anti-clogging capabilities. In this paper, the computational fluid dynamics–discrete element method (CFD-DEM) coupling model is used to study the influence of different conveying conditions and particle parameters on the wear of the flow components in a submersible sewage pump. At the same time, the energy balance equation is used to explore the influence mechanism of different tip clearance sizes on the internal flow pattern, wear, and energy conversion mechanism of the pump. This study demonstrates that increasing the particle volume fraction decreases the inlet particle velocity and intensifies wear in critical areas. When enlarging the tip clearance thickness from 0.4 mm to 1.0 mm, the leakage vortex formation at the inlet is enhanced, leading to increased wear rates in terms of the blade and volute. Consequently, the total energy loss and turbulent kinetic energy generation increased by 3.57% and 2.25%, respectively, while the local loss coefficient in regard to the impeller channel cross-section increased significantly. The findings in this study offer essential knowledge for enhancing the performance and ensuring the stable operation of pumps under solid–liquid two-phase flow conditions. [ABSTRACT FROM AUTHOR]

Al2O3-13wt. %TiO2 is a widely used coating material for the protection of metallic surfaces. The reduced graphene oxide (rGO) added alumina-titania composite coatings deposited using Air Plasma Spraying (APS) are used for enhancing the wear resistance of engineering components. In this work, the addition of rGO at varying weight percentages of 0.5, 1, and 1.5% to the Al2O3-13wt.%TiO2 powder resulted in composite coatings with improved microstructural characteristics, mechanical properties, and tribological performance. The use of SEM and XRD analyses revealed the presence of rGO between the coating splats, offering protection from crack initiation. Furthermore, there were noticeable changes in the microhardness and surface roughness of the coatings. Coatings reinforced with higher weight percentages of rGO had extremely low wear rates and offered a low coefficient of friction, with unpulled rGO acting as protective layers. However, it was also observed that the wear of coatings with 0.5 wt% and 1.0 wt% rGO addition was mainly due to the delimitation and subsequent pulverization at 1.5 kgf load and 0.17 m/s sliding speed. Overall, this work provides valuable insights into the use of composite coatings for enhancing the wear resistance of surfaces of components. [ABSTRACT FROM AUTHOR]

In this work, effect of multi-axial room temperature forging process on scratch and wear characteristics of Al-7.3 and Al-12.1Si alloys with varying cumulative strains was investigated. Al-7.3 and Al-12.1Si alloy ingots were remelted in a furnace and then poured into a preheated die to produce a cast sample of the desired shape and dimension for the MAF process. These samples were subjected to solution heat treatment before forging Scratch test was conducted to measure the scratch resistance of unprocessed and MAF-processed samples. Dry sliding wear tests were performed on a tribometer (pin-on-disk) at ambient temperatures. MAF-processed materials exhibited better scratch and wear resistance compared to as-cast materials. After MAF, wear mechanisms in both alloys shifted from adhesive and delamination wear to a combination of abrasive and a lesser amount of adhesive wear. Moreover, the degree of delamination significantly decreased after MAF-process. Improved scratch and wear resistance is mainly due to increased microhardness via refinement and improved uniformity in the redistribution of eutectic silicon as well as the strain hardening of the aluminum phase. [ABSTRACT FROM AUTHOR]

The study aimed to investigate the effects of wear parameters including impact energy, impact frequency, test time, and their interactions on the impact wear characteristics of high chromium white iron (HCWI) and zirconia toughened alumina (ZTA) reinforced HCWI composites fabricated by squeeze casting method using response surface methodology (RSM). The Box-Behnken Design (BBD) method was employed, and a linear model was developed to describe the relationship between wear loss and wear parameters, and to predict the wear behavior of the tested materials. The parameters of energy, frequency, and test time were found to be statistically significant, and positively influencing the wear behavior. Specifically, test time emerged as the most influential factor, followed by energy and frequency. The wear characteristics of HCWI are primarily characterized by shallower plowing and furrows, partial plastic deformation, surface spalling, and inserted abrasives. In contrast, the predominant wear mechanisms for ZTA/HCWI composites include slight breaking of ZTA particles, plowing, and cutting of the metal matrix; breaking and falling of ZTA particles; broken abrasive particles encrusted into the matrix; and the formation of spalling pits. [ABSTRACT FROM AUTHOR]

This research investigates the production of Cu-SiCw composites by using gas pressure infiltration method and the production of Al/Cu-SiCw composite by using the cold rolling method. The layers were bonded by three rolling reductions of 40 %, 50 %, and 60 %. The microstructures of composites before and after roll bonding were discussed based on SEM and EBSD images. Less agglomeration of whiskers was seen after higher rolling reductions which indicates better distribution of reinforcement in copper. In addition, no decomposition and reaction were observed in Cu-SiCw. The effect of rolling reductions on hardness, wear behavior, and tensile properties was also investigated. Hardness, yield, and ultimate strengths increased at higher rolling reductions. The yield and ultimate strengths increased from 118 MPa to 227 MPa after a 40 % rolling reduction to 150 MPa and 263 MPa after a 60 % rolling reduction. The measured friction coefficient and mass loss showed better wear resistance of composites at higher rolling reductions because the layers became hardened. The mass loss decreases from 6.46 mg after a 40 % rolling reduction to 5.42 mg after a 60 % rolling reduction. Worn surfaces based on SEM images showed shallower grooves and less remaining debris.

This paper investigates the thermo-mechanical and wear characterization of AA8011 aluminum alloy matrix based hybrid metal matrix composite reinforced with graphene and boron carbide (B4C) particles as reinforcement material. The weight percentage (wt.%) of graphene was maintained as 1 and wt.% of B4C was varied from 3 to 9 wt.% in steps of 3 wt.%. The influence of reinforcements and their wt.% on tensile, hardness, density, thermal and wear characteristics of AA8011 aluminum alloy matrix based hybrid metal matrix composite reinforced with graphene and boron carbide (B4C) particles were detailed. The morphology and microstructure of the composite specimens were interrogated through scanning electron microscope, transmission electron microscope and optical microscope. The X-ray diffraction spectrum ensured the presence of graphene and B4C reinforcements and the AA8011 aluminum alloy matrix in the fabricated composite specimens. The graphene and B4C reinforcements in AA8011 aluminum alloy matrix improved the tensile, hardness and wear characteristics of composite specimens by 19.8, 36.1 and 50.9% respectively for the composite specimens with 1 wt.% graphene and 6 wt.% B4C reinforcements. The optimal wt.% of reinforcements maximize the grain boundaries resulting in better mechanical and wear characteristics. [ABSTRACT FROM AUTHOR]

Ti2AlNb intermetallic alloy is currently the most promising lightweight high-temperature resistant material in the aerospace industry, owing to its high specific strength, favourable room temperature plasticity, outstanding temperature strength, and creep resistance. High speed cutting technology is characterized by low cutting force, minimal thermal deformation, high material machining efficiency and precision, which is widely used in machining TiAl intermetallic alloys and associated key components to ensure superior machined surface quality and dimensional accuracy. However, there are serious tool wear during high speed cutting of Ti2AlNb intermetallic alloys because of its high specific strength and temperature strength, and the tool wear mechanism is unknown. In this paper, the high-speed face milling trials of Ti2AlNb intermetallic alloys are performed to investigate tool wear evolutions and wear mechanisms. More specifically, tool wear morphologies, tool tip breakage, machined surface roughness, and cutting forces are investigated in detail. Results indicate that high-speed face milling results in severe tool wears, leading to a rapid increase in cutting forces and machined surface roughness during the severe wear stages. The tool's service life is limited to 228 s due to tool tip breakage resulted from coating delamination, cracking, and mechanical impact. Tool wear morphologies encompass tool rake face and flank face wear, exhibiting typical characteristics of coating delamination and microchipping. Adhesive wear and oxidation wear are the primary mechanisms of tool wear, occurring on both the rake face and flank face. The experimental results can provide a reference for high speed machining of TiAl material and promote the application of the material. [ABSTRACT FROM AUTHOR]

The Al–10Sr master alloy is used to modify the A359/20 wt% SiC composite, aiming to enhance its tensile properties and wear characteristics concurrently. This modification yields improvements surpassing those observed in pure A359 alloys, a phenomenon attributed to the preferential formation of Al–Si–Sr compounds adjacent to SiC particles. The results elucidate that the integration of SiC, serving as a wear‐resistant phase, substantially augments the wear resistance of the alloy. Abrasion marks incurred from singular friction events are discernibly more superficial on eutectic silicon in contrast to the aluminum substrate. Furthermore, the metamorphosis of eutectic silicon from an elongated to a granular form mitigates stress concentrations. This morphological alteration is pivotal, enhancing wear resistance and diminishing the likelihood of particle detachment. [ABSTRACT FROM AUTHOR]

The heat generation mechanism, wear behavior and quantitative relationship between cutting load and coal rock characteristics of the interaction between the cutting tool of mining machinery and coal rock mass, are the keys in solving the wear failure short life of the cutter, and realizing the safe and efficient heading. By comprehensively analyzing the impact of temperature on tool life, wear, and cutting efficiency, the temperature and wear distribution law of disc cutter in cutting coal rock are explored, and the heat generation mechanism and wear characteristics of disc cutter in cutting coal rock are revealed. Under the cutting conditions of non-vibration and axial excited vibration, the heat flux calculation formulas of the cutter wedge surface and the blade are established by friction work. Based on the semi-infinite heat transfer model under the condition of instantaneous point heat source and heat compensation principle, the heat transfer models of wedge irregular surface heat source and blade line heat source of disc cutter are given, and the temperature mathematical model of any point is established. Also, the influence of relevant parameters on the temperature field of cutter was solved and analyzed. Using the finite element ABAQUS, and discrete element EDEM software, the study simulates the temperature field and wear characteristics of disc cutter in cutting coal rock at different feed speeds, and sets up an experimental system for vibration cutting coal rock with disc cutter. Furthermore, the study tests the temperature characteristics of coal rock broken by disc cutter, and comprehensively investigates the distribution law of temperature and wear behavior characteristics of disc cutter in theory, simulation, and experiment. The results show that the characteristics of temperature variation of disc cutter are mainly concentrated on the blade, which decreases gradually from the blade to the wedge surface. The temperature distribution along the circumference of disc cutter is like a parabola, and the temperature decreases gradually from the middle blade to both sides. Under different feed speeds, the steady-state average maximum temperatures obtained by theoretical calculation (cutting time tends to infinity) of non-vibration and axial excited vibration are 374.76 ℃ and 245.72 ℃ respectively. The average maximum temperatures obtained by simulation (cutting time is about 3 s) are 80.13 ℃ and 73.60 ℃ respectively, and the average maximum temperature without vibration is 8.87% higher than that with vibration. And the experimental results (cutting time is about 3 s) are 72.56 ℃ and 66.99 ℃, and the average maximum temperature without vibration is 8.45% higher than that with vibration, the average error between simulation and experiment is 11.69%. In the experimental process of disc cutter in cutting coal rock, the circumferential spin phenomenon of the cutter is conducive to its evenly wear, and vibration cutting is more obvious than non-vibration. The temperature dissipation of the disc cutter blade presents a nonlinear downward trend, which is rapidly transferred from the blade to the wedge surface, its structural form can avoid aggravating the local wear of the cutter due to the accumulation and concentration of temperature. The disc cutter wear is concentrated at the blade, the relative wear along the circumference is a parabola distribution, the relative wear of the middle blade is larger, and the relative wear of the two side blades is gradually reduced. And the ABAQUS simulation combined the cutter wear model estimates the characteristic law of relative blade wear, which are the same as that obtained by EDEM simulation. The relative wear amount of disc cutter circumference is consistent with the temperature characteristic law, the correlation coefficients are higher than 0.90, cutting temperature can characterize the cutter wear. The internal connection between the temperature distribution characteristics of disc cutter in cutting coal rock and its wear law is obtained by comprehensive theory, simulation, and experiment, the three temperature variation laws are consistent, which verifies the accuracy and effectiveness of the cutter heat transfer model.

The deep sea harbors abundant mineral, oil, and gas resources, making it highly valuable for commercial development, including the extraction of minerals. Due to the relatively large particle size of these minerals, how they interact with fluids is significantly different from that of small particles. However, there has been limited simulation research on the impacts of large particles (the diameter of particles is at the level of centimeters) on the flow and wear characteristics in bends, because the simulation of the particles at such a size is difficult. Additionally, in the field of deep-sea mining, multiple bends are simultaneously connected in series, and the wear in such bends has garnered increasing attention. Based on an improved CFD-DEM model, this article solved the issue that traditional unresolved CFD-DEM methods cannot accurately simulate large particles in a hydraulic conveying pipe and bend. After validating the accuracy of this model against classical experiments, the paper comprehensively analyzes the modulation effect of large particles on turbulence, and the effects of different particle diameters, particle transport concentrations, and transport velocities on the wear of bends connected serially. Finally, the bends connected serially in various configurations are simulated to study the wear on the bent interior surfaces. Results indicate a pronounced modulation effect of large particles on turbulence at higher transport concentrations; the wear rate in the combined bends does not exhibit a linear correlation with the collision frequency of particles on the wall surface. Furthermore, different configurations of serially connected bends exhibit significant differences in the wear morphology of the second bend. [ABSTRACT FROM AUTHOR]

The rotational speeds of moulds in a typical vertical centrifugal machine are found to greatly affect the resulting quality of cast tubes as seen through multiple parameters such as finishing texture strength etc. The dependence of the quality of mold on the speed can be attributed to the movement of molten metal, which in turn, is dictated by the speed of rotation. The present work is an effort to experimentally demonstrate this feature. The Alloy used in the work was Al-17%Si. The speeds of interest that were used for experimentation ranged from a minimum of 600 Revolutions Per Minute (RPM) to a maximum of 1200 Revolutions Per Minute (RPM). The results of the experiment were very affirmative towards the fact that the best quality can indeed be obtained for the said range of speeds. Further, a few experiments, beyond this range of speed, showed strikingly lowquality molds characterized by features such as coarse grain, low mechanical strength, and wear properties. [ABSTRACT FROM AUTHOR]

Purpose – It is quite universal for high-speed turnouts to be exposed to the wear of the stock rail of the switch rail during the service process. The wear will cause the change of railhead profile and the relative positions of the switch rail and the stock rail, which will directly affect the wheel–rail contact state and wheel load transition when a train passes the turnout and will further impose serious impacts on the safety and stability of train operation. The purpose of this paper is to provide suggestions for wear management of high-speed turnout. Design/methodology/approach – The actual wear characteristics of switch rails of high-speed turnouts in different guiding directions were studied based on the monitoring results on site; the authorized wear limits for the switch rails of high-speed turnout were studied through derailment risk analysis and switch rail strength analysis. Findings – The results show that: the major factor for the service life of a curved switch rail is the lateral wear. The wear characteristics of the curved switch rail of a facing turnout are significantly different from those of a trailing turnout. To be specific, the lateral wear of the curved switch rail mainly occurs in the narrower section at its front end for a trailing turnout, but in the wider section at its rear end when for a facing turnout. The maximum lateral wear of a dismounted switch rail from a trailing turnout is found on the 15-mm wide section and is 3.9 mm, which does not reach the specified limit of 6 mm. For comparison, the lateral wear of a dismounted switch rail from a facing turnout is found from the 35-mm wide section to the full-width section and is greater than 7.5 mm, which exceeds the specified limit. Based on this, in addition to meeting the requirements of maintenance rules, the allowed wear of switch rails of high-speed turnout shall be so that the dangerous area with a tangent angle of wheel profile smaller than 43.6° will not contact the switch rail when the wheel is lifted by 2 mm. Accordingly, the lateral wear limit at the 5-mm wide section of the curved switch rail shall be reduced from 6 mm (as specified) to 3.5 mm. Originality/value – The work in this paper is of reference significance to the research on the development law of rail wear in high-speed turnout area and the formulation of relevant standards.

In order to improve the contact strength and reduce the sliding friction of the gear pair, an internal cylindrical gear pair with a curved meshing line is studied in this paper. Firstly, a curved meshing line is designed. The tooth profiles of the internal gear pair with the designed meshing line are calculated by using differential geometry and the gear meshing principle. Secondly, a wear model is established by combining the finite element method and the Archard wear formula. Then, a numerical simulation is conducted; the relative curvature, sliding coefficient, sliding distance, maximum contact pressure, transmission error, and wear depth are calculated. Ultimately, the variation law of tooth surface wear of new gear with and without installation errors is observed under different stress cycles. On this basis, the influence of tooth modification on tooth surface wear is further researched. Through the results, the advantages of the introduced novel internal cylindrical gears in wear resistance are further demonstrated. The study in this paper provides new research ideas and methods for gear wear research and gear design.

In this study, we investigated the effect of particle size distribution (PSD) variations on the particle motion characteristics and wear in centrifugal pumps. We used computational fluid dynamics (CFD) and the discrete element method (DEM) to conduct simulations for one single particle size and five mixed particle sizes. The variation of the PSD had a significant effect on the wear rate of the impeller pressure surface and the volute surface. When the proportion of small particles near the impeller increased, the wear rate decreased. Specifically, at the middle of the impeller, the wear rate changed the most significantly. For volute surfaces 6–7 and 7–8 and the diffusion section, the velocity vectors of the near-wall volute surface showed a greater accumulation of small particles, and the buffering effect on the impact of large particles increased. Thus, the addition of small particles caused the wear rate of the volute surface to decrease. [ABSTRACT FROM AUTHOR]

This research investigates the tribological characteristics and sustainability of WS2 deposited Al 6061-T6 surface under dry sliding conditions and optimizes the wear parameters to enhance the tribological behaviour and discuss its sustainability. The experiment used the Box–Behnken design, which examines the effective interaction between dry sliding parameters and specific wear rate (SWR) and friction coefficient (COF). By varying the load (L), sliding velocity (V) and distance (D), the wear behaviour of WS2 deposition against EN 31 steel was examined through the pin-on-disc experiment. Grooving, debris formation, polishing, tribolayer, ploughing, transfer material, smearing, delamination and pitting are observed through scanning electron microscope (SEM) analysis. For optimum conditions, SEM with energy dispersive spectroscopy was utilized to characterize the worn surface, and X-Ray diffraction (XRD) patterns confirmed the phases of W, WO3, WS2, Al, AlO, Al2S3 and Al4C3. [ABSTRACT FROM AUTHOR]

Aiming at the wear failure of tubing string caused by the nonlinear flow-induced vibration（FIV） in high-temperature, high-pressure and high-yield（3H） gas wells, the nonlinear FIV model of tubing string was established using the element method, energy method and Hamilton variational principle, which considered the changes of wellbore trajectory, wellbore temperature/pressure, and contact of casing. A simulation experiment of the tubing string vibration was conducted to verify the correctness and validity of the nonlinear vibration model. Based on the White-Fleisher wear theory, a calculation method for the wear amount and depth of tubing string in 3H gas wells is proposed. The wear unit test is carried out, and the friction coefficient and wear efficiency are determined. On this basis, the influence of production rate, well angle, well section length, packer position and centralizer position on wear characteristics of tubing is systematically analyzed. The safety control methods of tubing string were proposed, namely, which shown that, firstly, with the increase of production rate, the wear life of the string decreases, and there is a sudden value, which can be determine using the analysis method, so that the field production allocation should be far away from the sudden production rate. Secondly, in the well trajectory design, the length of vertical well section should be reduced, and the length of build section and the angle of stable inclined section should be increased. Thirdly, there is an optimal position of packer and centralizer in the field, which is related to the well structure, string structure and downhole tool size, and can be determined by the proposed analysis method to guide the design of packer and centralizer. The research results can effectively improve the service life of tubing string in 3H gas wells.

The C++ programming language is employed to improve the Computational Fluid Dynamics (CFD)- Discrete Element Method (DEM) coupling interface in this paper, the accuracy of solid-liquid two-phase flow numerical model are validated through experiments. Subsequently, the wear characteristics of the U-shaped elbows under different elbows spacing, bending diameter ratio, particle volume concentration, and particle size are investigated. The research results indicate that as the spacing between bends is increased, the phenomenon of particle sedimentation is intensified, and the maximum collision angle in elbow 2 is increased. The location of the maximum collision angle is closer to the outlet of elbow 2. However, both the collision frequency and wear rate are reduced due to the decrease in the number of particles. Smoother particle flow and a reduction in the collision angle and wear rate of particles on both bends are achieved by increasing the bend ratio. During the variation of the particle volume fraction from 0.5% to 7%, the increase in collision frequency and wear rate of both bends is slowed down. A greater decrease is observed in elbow 2, but the “shielding effect” is not observed. Furthermore, at low volume fractions, kinetic energy is lost by particles as they flow through elbow 1, resulting in a lower average wear rate in elbow 2 compared to elbow 1. Conversely, at high volume fractions, the opposite effect occurs. Finally, when keeping the particle volume fraction constant, an increase in the particle size leads to a smaller wear area in both bends. The wear rate in elbow 1 increases at a slower rate, while the wear rate in elbow 2 exhibits an initial increase followed by a decrease trend.

In order to investigate the wear characteristics of pantograph slide in pantogragh-catenary under different current, contact pressure and sliding speed, current-carrying wear experiments were carried out to study the current-carrying efficiency, arc energy, friction coefficient and temperature of the friction pair under different working conditions. The wear area of the slide was measured in blocks and multiple times after the experiments, and the surface topography images and roughness parameters of the slides were collected by metallographic microscope and surface roughness instrument respectively. An image processing method based on Otsu algorithm was used to extract pits from the topography images and perform mark calculation, and the variation of the area and number of pits, and the roughness parameters (contour arithmetic mean deviation and maximum contour valley depth) under different working conditions was statistically analyzed. The results show that with the increase of current, the area and number of pits increase, and the roughness parameters decrease. With the increase of contact pressure, the area of pits decreases, the number of pits decreases first and then increases slightly, and the roughness parameters decrease. With the increase of sliding speed, the area and number of pits and the roughness parameters increase. [ABSTRACT FROM AUTHOR]

W-Si-C composites with high relative densities and good mechanical and wear properties were successfully prepared by spark plasma sintering. The influence of SiC content on the relative density, microstructure, mechanical properties and wear characteristics was investigated. The results indicated that the reaction between SiC and W at their interface produced W2C and W5Si3. SiC also reacted with oxygen impurities at the W grain boundary to form SiO2. The purification of the grain boundaries of W was carried out by SiO2 synthesis. Reactive sintering reduces the free energy of the system and facilitates the densification process of W-Si-C composites. This results in a significant increase in the relative density of W-Si-C composites, which reaches a maximum of 98.12%, higher than the 94.32% of pure tungsten. The hardness significantly increases from 4.33 GPa to 8.40 GPa when the SiC content is 2 wt% compared to pure tungsten due to the generation of the hard ceramic phase and the increase in relative density. The wear resistance of the W-Si-C composites was significantly improved with little SiC addition. The wear rate significantly decreased from 313.27 × 10−3 mm3/N·m of pure tungsten to 5.71 × 10−3 mm3/N·m of W-0.5 wt% SiC. SEM analyses revealed that the dominant wear mechanism of pure tungsten was attributed to fatigue wear, while that of W-Si-C composites was due to abrasive wear. [ABSTRACT FROM AUTHOR]

Ultrasonic vibration-assisted grinding has been employed in machining difficult-to-cut materials (e.g. titanium alloys, superalloys, composites, hardened steels, etc.) aiming at improving wear-resistance abilities of abrasive wheels. In this paper, comparative experiments between the conventional grinding (CG) and ultrasonic vibration-assisted grinding (UVAG) were performed on AISI 9310 steel to study grain wear mechanisms. Results shows that UVAG achieves a significant reduction in grinding forces, force ratio and machined quality as material removal volumes raise. Moreover, the wear flat of grains and a sharp change in grinding forces occur. Then, the surface quality gradually deteriorates from the more severe chip clogging of wheels and increasing grinding forces during the CG process. Meanwhile, the steady wear stage of UVAG is longer by 23.07%, and the ground surface roughness in UVAG remain lower and more stably fluctuating than those in CG. Furthermore, UVAG possesses a small fluctuating height of worn grains according to the analysis of the protrusion height distribution at various wear stages, owing to the consistent micro-fractures of the grains under uniform alternating loads. In contrast, pull-out defects can be observed under high grinding forces on the tool–workpiece intersection during the CG process, affecting the ground surface quality. [ABSTRACT FROM AUTHOR]

This work presents the comprehensive characterization of alkali treated areca fruit husk fiber (AAFHF) an industrial agro‐waste reinforced unsaturated polyester resin (UPR) matrix hybrid composite with silicon carbide (SiC) nanoparticles as filler material. Hybrid composite plates were fabricated with 40 wt% of AAFHF and diverse wt% of SiC nanoparticles ranging from 1 to 4 wt% in steps of 1 wt%. The effect of wt% of SiC nanoparticles in hybrid composite over mechanical, morphological, wear, thermal and water absorption characteristics was investigated. The findings help to conclude that a hybrid composite plate with 3 wt% filler content excels in overall properties. Meanwhile, the accumulation and meager scattering of SiC nanoparticles in composite deteriorated the functional characteristics when the wt% of filler content enhanced to 4 wt%. Also, the failure pattern and interaction between AAFHF, SiC nanoparticle and UPR were understood from the images obtained using Scanning Electron Microscopy (SEM). In addition, the availability of functional groups, crystallite size and crystallinity index was obtained from Fourier transform infrared (FTIR) spectrum and X‐ray diffraction (XRD) analysis for the optimum filler content respectively. Moreover, the achieved results suggest the suitability of the developed composite for marine and lightweight applications. [ABSTRACT FROM AUTHOR]

In a deep-sea mining system, coarse-grained minerals are transported most of the time, which puts greater demands on the hydraulic performance and wear resistance of the mining pump than the transport of other types of materials. The pump performance is affected by the parameters of its main flow passage components. The parameters of the impeller were studied in depth to propose a novel mining pump, and the wear conditions of single-stage mining pump produced by different types of solid particles and operating conditions were analyzed. After numerical simulations of 29 models were conducted, the response surface methodology (RSM) was used to develop an optimized pump model that achieves better performance than the original model. The efficiency is improved by 1.2%, head is reduced by 0.34 m, and the impeller average wear intensity is reduced by 29.5% under rated conditions. [ABSTRACT FROM AUTHOR]

• Wear mechanisms of gear with initial defects of bearing inner ring. • Monitoring and fault diagnosis of gear condition. • Employs a multi-analytical approach including vibration signal analysis, wear debris concentration analysis, qualitative analysis of the wear debris, and tooth surface analysis. • The combination of experimental research and simulation analysis. This study investigated the wear characteristics and operational condition of gears with initial defects of the bearing inner ring. The working states of gears were evaluated through a combination of vibration signal analysis, wear debris concentration analysis, qualitative analysis of the wear debris, and tooth surface analysis. Based on the Hertz contact theory, a dynamic model for the gear drive system was constructed, enabling the simulation and comparison of vibration acceleration signals under normal and fault conditions. The research results revealed that bearing defects induced irregularities in vibration frequency and amplitude, adversely affecting the performance and stability of the gear system. Furthermore, these defects trigger the creation of substantial wear debris, which exacerbates gear wear and reduces the gear lifespan by about 15%. Additionally, bearing defects induced intermittent load spikes and uneven stress distribution across tooth contacts, resulting in localized high shear stresses, material flaking, and surface spalling. Consequently, initial defects of the bearing will accelerate gear wear progression and lead to abnormal wear patterns, potentially resulting in the premature failure of the gear train system. The study investigates the underlying mechanisms of gear wear evolution influenced by these defects and offers practical guidelines for the engineering, manufacturing, and maintenance of gear systems. [ABSTRACT FROM AUTHOR]

The deep sea harbors abundant mineral, oil, and gas resources, making it highly valuable for commercial development, including the extraction of minerals. Due to the relatively large particle size of these minerals, how they interact with fluids is significantly different from that of small particles. However, there has been limited simulation research on the impacts of large particles (the diameter of particles is at the level of centimeters) on the flow and wear characteristics in bends, because the simulation of the particles at such a size is difficult. Additionally, in the field of deep-sea mining, multiple bends are simultaneously connected in series, and the wear in such bends has garnered increasing attention. Based on an improved CFD-DEM model, this article solved the issue that traditional unresolved CFD-DEM methods cannot accurately simulate large particles in a hydraulic conveying pipe and bend. After validating the accuracy of this model against classical experiments, the paper comprehensively analyzes the modulation effect of large particles on turbulence, and the effects of different particle diameters, particle transport concentrations, and transport velocities on the wear of bends connected serially. Finally, the bends connected serially in various configurations are simulated to study the wear on the bent interior surfaces. Results indicate a pronounced modulation effect of large particles on turbulence at higher transport concentrations; the wear rate in the combined bends does not exhibit a linear correlation with the collision frequency of particles on the wall surface. Furthermore, different configurations of serially connected bends exhibit significant differences in the wear morphology of the second bend.

An AA2017-aluminum nitride composite was created through stir casting, and its tribological properties, like hardness and wear rate were examined by varying the aluminum nitride content from 5% to 15%. A numerical model was established to predict the wear rates of aluminum metal matrix composites (MMCs), and the accuracy of the model was confirmed through an analysis of variance (ANOVA). The findings demonstrated that the addition of aluminum nitride to AA2017 resulted in improved mechanical and wear characteristics for the composites. Furthermore, the utilization of sustainable materials and manufacturing techniques underscores the potential for environmentally responsible engineering solutions in material science and manufacturing processes. Aluminum nitride emerged as a critical component in enhancing the wear resistance of the metal matrix composites, contributing to their overall durability and sustainability.

Abstract The current research of nuclear control rod drive mechanism (CRDM) movable latch only makes a simple measurement of wear mass. The wear volume and difference in various claw surfaces are ignored and the degradation mechanism of each claw surface is not clear. In this paper, a detailed degradation analysis was carried out on each claw surface of movable latch combined with wear result and worn morphology. Results indicate that the boundary of carbide is preferred for corrosion because carbide presents a nobler Volta potential compared to the metal matrix or boundary region. Due to the oscillation of drive shaft between the claw surfaces of movable latch, the dominant wear mechanism on the upper surface of claw (USC) and lower surface of claw (LSC) is plastic deformation caused by impact wear. Mechanical impact wear will cause the fragmentation of carbides because of the high hardness and low ductility of carbides. Corrosion promotes the broken carbides to fall off from the metal matrix. The generated fine carbides (abrasive particles) cause extra abrasive wear on USC when the movable brings the drive shaft upward or downward. As a result, USC has a higher wear volume than LSC. This research proposes a method to evaluate the wear on the whole movable latches using a 3D full-size scanner.

The wear condition of diamond tools determines its service life. The 6061-T6 magnesium-aluminum alloy workpiece was cutted with diamond PCD tool. Through the changes of cutting forces and cutting temperatures at different cutting speeds, cutting depths, vibration frequencies and tool back angles, the workpiece surface roughnesses and tool wear areas at different tool back and forth angles, feed values and speeds of revolution were studied. The results show that the cutting forces and the cutting temperatures increase with the increase of cutting speeds and cutting depths, and decrease with the increase of vibration frequencies. With the increase of the tool back angles, the cutting forces of diamond tool decrease first and then increase slowly, but it has little effect on the cutting temperatures. When the rake angle of the tool is 10°, the back angle of the tool is 8°, the cutting speed is 0.46 m/s, the cutting depth is 28 μm, the feed value is 0.10 mm/r, the speed of revolution is 4 100 r/min, the vibration frequency is 22 kHz and the cutting amplitude is 9 μm, the diamond tool has the smallest wear area, the lowest degree of wear and the longest service life, but the surface roughness of the workpiece is slightly higher.

In view of the wear failure caused by the flow-induced vibration of tubing string in high- pressure, high-temperature, and high-yield (3H) gas wells of the South China Sea, an orthogonal test of 13Cr- L80 tubing-casing wear was carried out using UMT-TRIBOLAB reciprocating friction/wear testing machine. Influences of operation parameters on the wear characteristics of tubing string were investigated by range analysis and variance analysis. It was found that: (1) Main wear patterns of oil and casing are abrasive wear and adhesive wear, and slight corrosion wear occurs locally; (2) Significant order of influence on tubing wear is positive pressure reciprocating stroke > friction frequency completion fluid density wear time, and significant order of influence on the friction coefficient of tubing is reciprocating stroke completion fluid density friction frequency positive pressure wear time; (3) Wear amount of tubing increases with the increase of contact load and slip stroke, while the influence of friction coefficient with contact load is not obvious. However, with the increase of completion fluid density, the wear characteristics of tubing and casing decrease significantly; (4) In field operation, reducing the contact load, the vibration frequency, the longitudinal vibration displacement of tubing and increasing the density of completion fluid can effectively improve the wear life of tubing string in 3H gas wells. [ABSTRACT FROM AUTHOR]

The frequent impulse collisions and wear between the ball and cage pocket not only affect the bearing stability but also significantly impact the deterioration of the bearing service life. A comprehensive dynamic model for analyzing the stability, skidding degree, ball–cage collision, wear distribution, and wear rate of four types of cage pocket is proposed. A series of tests of cage whirling conducted on self-lubricating bearing test bench using high-speed photographic technology have proven the accuracy of the model. It is found that the cage with a combination of circle and rectangle pockets has the highest stability. The circle pocket has a larger collision area and higher wear rate than rectangle and diamond pockets. The combined rectangle–diamond pocket has a better wear resistance. [ABSTRACT FROM AUTHOR]

The examination of the existing relationships between nanoindentation responses and tribological properties of the nanostructured CrN, Cr(CN), and (CrTi)N coatings was the matters to be considered in this research. A cathodic arc physical vapor deposition machine was therefore implemented to apply the chosen coatings on the DIN 1.2510 tool steel substrate. Moreover, an X‐ray diffraction and a field emission scanning electron microscope were utilized in order to show the features regarding microstructure and morphology of these very coatings. The mechanical and tribological behavior of the coatings was expected to be assessed with the use of a nanoindentation and pin‐on‐disc wear tests. According to the obtained result, the wear resistance and hardness value of the (CrTi)N coating were proved to be much better than those of the CrN and Cr(CN). Linear equations were proposed between wear rate/hardness and friction coefficient/hardness to evaluate the correlation between mechanical and tribological properties. The presence of a quadratic equation between the friction coefficient and the plastic deformation index was also discovered. [ABSTRACT FROM AUTHOR]

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• Hardfacing is done by Cold Metal Transfer using the sinewave weaving pattern. • Sinewave weaving enhances fluidity and restricts lateral flow of coated material. • Increasing in heat transfer promotes formation of fine grains. • Hardfaced layer shows better mechanical and wear properties than base substrate. In this research, the sinewave weaving technique is used by the Cold Metal Transfer process for hard-facing the Inconel 718 over the Stainless Steel 304. A microstructural study exhibited columnar grains that were transformed into equiaxed grains. Scanning Electron Microscopy (SEM) – Energy Dispersive X-ray analysis (EDX) results confirm the element's segregation and secondary phase's formation. Outcomes of hardness, tensile, impact measurements, and wear analysis show that a hard-faced layer offers better hardness and wear resistance. [ABSTRACT FROM AUTHOR]

This study investigated the influence of pre-processing heat treatment on the fast-multiple rotation rolling (FMRR) of Al-16Si-4Cu alloy friction-surfaced onto the AA1050 aluminum substrate. Results showed that applying solid solution treatment before both the friction surfacing and FMRR processes yielded the thinnest coating thickness (1.4 ± 0.2 mm). Moreover, using a solid solution-treated Al-16Si-4Cu alloy rod resulted in the smallest average size of Si particles (4.2 ± 0.1 μm) in the FMRR-treated layer. Additionally, the most uniform distribution and smallest size of Al 2 Cu precipitates in the FMRR-treated layer were achieved by subjecting the alloy to solid solution treatment prior to both FMRR and friction surfacing. Notably, solid solution treatment preceding both FMRR and friction surfacing processes produced maximum nano-hardness (10.42 ± 0.54 GPa), shear strength (174.32 ± 9.21 MPa), and elastic modulus (221.03 ± 0.54 GPa) in the clad layer. Furthermore, pre-processing with solid solution heat treatment led to the lowest wear rate of the clad layer, exhibiting a reduction of 74.47 % compared to the AA1050 substrate. • The effect of pre-processing heat treatment on the fast-multiple rotation rolling of Al-16Si-4Cu alloy was investigated. • The solid solution treatment results in maximum nano-hardness (10.42 ± 0.54 GPa) in the clad layer. • Uniform distribution of Al 2 Cu precipitates was achieved by subjecting the alloy to solid solution treatment. [ABSTRACT FROM AUTHOR]

W-Si-C composites with high relative densities and good mechanical and wear properties were successfully prepared by spark plasma sintering. The influence of SiC content on the relative density, microstructure, mechanical properties and wear characteristics was investigated. The results indicated that the reaction between SiC and W at their interface produced W2C and W5Si3. SiC also reacted with oxygen impurities at the W grain boundary to form SiO2. The purification of the grain boundaries of W was carried out by SiO2 synthesis. Reactive sintering reduces the free energy of the system and facilitates the densification process of W-Si-C composites. This results in a significant increase in the relative density of W-Si-C composites, which reaches a maximum of 98.12%, higher than the 94.32% of pure tungsten. The hardness significantly increases from 4.33 GPa to 8.40 GPa when the SiC content is 2 wt% compared to pure tungsten due to the generation of the hard ceramic phase and the increase in relative density. The wear resistance of the W-Si-C composites was significantly improved with little SiC addition. The wear rate significantly decreased from 313.27 × 10−3 mm3/N·m of pure tungsten to 5.71 × 10−3 mm3/N·m of W-0.5 wt% SiC. SEM analyses revealed that the dominant wear mechanism of pure tungsten was attributed to fatigue wear, while that of W-Si-C composites was due to abrasive wear.

The influence of the number of passes and the tube materials on the microstructural evolution, mechanical properties, and wear behavior of Cu and brass tubes after parallel tubular channel angular pressing (PTCAP) was investigated. The grain size decreased to final grain sizes of 138.6 nm and 142.7 nm, after PTCAP of the Cu and brass tubes was conducted in up to 4 and 2 passes, respectively. PTCAP contributes to obtaining an ultra-fine grain (UFG) microstructure, with a mixture of different grain sizes that conferred high hardness. The present results indicate the superior wear resistance of Cu and brass PTCAP tubes, relative to Cu and brass samples that were previously deformed by different severe plastic deformation (SPD) processes. The wear mechanism of the Cu tubes changed from delamination and cracks with a high degree of adhesive wear before PTCAP into a combination of adhesive and abrasive wear, with a decrease in the presence of oxygen content after the PTCAP procedure. The wear mechanism also changed from a combination of adhesive and abrasive mechanisms into abrasive ones with the absence of oxygen after the PTCAP of brass tubes. [ABSTRACT FROM AUTHOR]

Copyright of Materials & Technologies / Materiali in Tehnologije is the property of Institute of Metals & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)