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Wear is one of the main problems encountered in industrial operations, generating high costs due to equipment failures for constant replacement of parts. By implementing technologies designed to enhance wear resistance, losses can be minimized in industries such as mining, cement, sugar and ethanol, and steel production. A key solution to reducing maintenance costs from wear is the application of highly abrasion-resistant alloys through welded hardfacing on coated sheets. Therefore, the objective was to investigate the microstructure and wear resistance of two high chromium hardfacing alloys with Fe–C-Cr and Fe–C-Cr-Nb-B systems used in the manufacture of wear resistance, deposited using tubular wires. This study also aims to assess the variation in wear rate based on the alloy composition in the coatings. Firstly, the characterization of the materials was carried out through chemical and microstructural analysis through scanning electron microscopy (SEM), X-ray diffraction (XRD), and hardness. A comparative analysis of the friction coefficient and wear resistance was carried out using the ASTM G133–Linearly Reciprocating Ball-on-Flat Sliding Wear test, where the worn volume was analyzed by optical profilometry. The Fe–C-Cr-Nb-B system alloy presented higher hardness values and lower volume loss than the Fe–C-Cr system alloy due to the presence of niobium primary carbides dispersed throughout the coating, promoting greater matrix protection and, consequently, less abrasive wear. The results were coherent and provided data that can lead to a better selection of materials among solutions in the manufacture of wear-resistant sheets and hard coatings deposited by welding in the industry. [ABSTRACT FROM AUTHOR]

Purpose: Today, wear and tear is a metaphor whose cost cannot be ignored by real sector. For this reason, many sectoral and academic studies are carried out to minimize the wear effect. This study aims to create a perspective against wear problems for the automotive industry as well. Design/methodology/approach: The 16MnC5 material, which is used as the U-joint material in the powertrain of the automotive industry, was subjected to heat treatment such as normalization and carburization at certain temperatures and duration. By subjecting the resulting carbide thickness to the abrasion process, the maximum effective heat treatment parameters against wear were determined. Findings: It has been determined that the ideal cementation condition for 16MnCr5 steel to be used in the wear system is carburized samples at 900 °C for 3.5 h with a hardness depth of 1.04 mm. Originality/value: The variation in which the surface hardness thickness and surface roughness obtained by different heat treatment variations of the U-joint part, which is one of the cardan shaft components that provide power transmission of heavy commercial vehicles, show the best wear resistance, were investigated. As a result of this study, the study is to prevent the waste of limited materials in the world and to reduce the repair and maintenance costs of commercial vehicles. Peer review: The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2024-0152/ [ABSTRACT FROM AUTHOR]

The wind turbine blades are exposed, during functioning, to the abrasive wear generated by the impact with air-borne sand particles. In this work, samples of a commercial wind turbine blade, made of a multi-layered composite material, are subjected to abrasive wear tests, using an air streamed wearing particles test rig. Following the analysis of the tests' results was found that the only protection against failure of the blade by abrasive damage is the surface layer. After its' penetration, the layers below are quickly destroyed, leading to the blade destruction. The investigation of the main abrasive wear influencing factors—particles' speed and acting time, showed that the particles' speed is the most important. To prove that an artificial neural network-based model was used. Also, a method for improvement of the blade resistance to abrasive wear is proposed, consisting of applying on the blade's surface of a polymeric foil. This offers supplementary protection of the surface layer, delaying its degradation. The tests performed on the protected samples prove the validity of the proposed method. Overall, the work showed the weakness of the blades' resistance in case of working in abrasive wear conditions and identified an improving method. [ABSTRACT FROM AUTHOR]

In this work, the cost-effective precision finishing of electroless nickel plating using a compliant tool is presented. The shape adaptive grinding (SAG) process with diamond abrasive polishing pad is used for finishing of a plated surface on a stainless-steel substrate. The variable parameters in the SAG are tool compression, rotational speed of the tool, and particle size of diamond abrasive pads (9, 15, and 30 µm). Forces acting on the workpiece and areal surface roughness are the output parameters. Diamond abrasive pads are characterized for particle distribution and topography. Detailed topographical analysis of abrasive pads provides a better understanding of the change in surface characteristics and material removal mechanism with the different abrasive sizes. It is observed that fine diamond abrasive pads generate low surface roughness, while medium and coarse pads have higher wear resistance. The final finishing is performed at the optimal process parameters, and the final areal surface roughness of 7 nm is achieved. The topography, morphology, and wettability of the surface after finishing are analysed to correlate the effect of operating conditions. The article also highlights the pad loading and abrasive wear that significantly affect the outcome of the polishing process. [ABSTRACT FROM AUTHOR]

High-strength martensitic steels with boron are among the leading materials widely recognized for their exceptional resistance to abrasive wear. These steels exhibit some of the highest strength indices among bulk steels, a result of their specific chemical composition, thermomechanical rolling processes at the steel mill, and the use of pure, high-quality ores. With hardness values ranging from 400 to 650 HBW, they are ideal for demanding applications such as excavator buckets, plow blades, shafts, wear-resistant bars, and container liners. One critical microstructural property contributing to their high mechanical performance is the prior austenite grain size (PAG). A finer grain structure is associated with enhanced plasticity, and plastic deformation plays a significant role in abrasive wear mechanisms. However, this relationship between grain size and wear resistance is not well-documented in the literature, with few studies providing specific quantitative data. To address this gap, the authors conducted a study to examine the effect of prior austenite grain size on wear resistance when exposed to loose abrasive electrofused alumina no. 90. The findings indicate that applying targeted heat treatment can increase hardness by 58 Brinell units compared to the as-delivered condition. Moreover, as grain size increases from 18 µm to 130 µm, the relative abrasive wear resistance coefficient Kb decreases from 1.00 (for Hardox 500 steel in its as-delivered state) to 0.80 for austenitized material treated at 1200 °C. [ABSTRACT FROM AUTHOR]

Finding the correlation among manufacturing process, microstructure and mechanical properties is critical to design the high-performance alloy. In this study, room temperature ball-on-flat dry sliding wear behavior of carbide-reinforced Ni-Co-Cr-Mo-Cu alloys prepared by hot isostatic pressing (HIP) and hot extrusion (HEX) against Al2O3 ball were investigated. Carbides in the HIP alloy are fine, nearly spherical and have a higher area fraction, in comparison with HEX alloy. Abrasive wear dominates under 10 N load condition, large-sized carbides in HEX alloy display a better resistance to HIP alloy. Oxidative wear dominates under 30 and 50 N load condition, the nearly spherical carbides in the HIP alloy form a stable mixed glaze layer with the fully oxidized alloy surface, lower coefficient of friction (COF) and wear rate were obtained in comparison with HEX alloy. The significant decrease in the wear rate of Al2O3 against HIP alloys under 30 and 50 N load condition is due to the lubricating effect of the oxide glaze layer. The wear rate of the Al2O3 against the HEX alloys almost unchanged due to the insufficient lubrication. It is speculated that the absence of the glaze layer in the HEX alloy is due to the irregular shape of its carbides. [ABSTRACT FROM AUTHOR]

In situ TiC ceramic particle-reinforced steel matrix composites, typically produced via liquid metal infiltration of unstructured preforms, often demonstrate issues with composite areas being prone to fracture. To address this problem, particles with an average diameter of 3 mm were constructed and used to fabricate preforms. Using the in situ self-generation method, the composites were then synthesised with liquid Mn18Cr2. To control the degree of in situ spontaneous reaction, moderator alloy powders at concentrations of 20, 30, 40 and 50 wt.% were utilised. The results reveal that the TiC particle size in the composites gradually decreases as the moderator concentration in the preform increases, reducing from 1.31 to 0.92 μm. The microhardness and elastic modulus at the composite interfaces are intermediate between those of the TiC ceramic particles and the high manganese steel matrix. The inclusion of millimetre-scale architecture enhances the tensile strength of the composites, with tensile strength gradually increasing as the moderator content decreases. This study offers a comprehensive understanding of how moderator content influences the microstructure and mechanical properties of TiC-reinforced Mn18Cr2 composites, providing valuable insights for the development of high-performance structural materials. [ABSTRACT FROM AUTHOR]

Ultralow-wear polyethylene (ULWPE) was proposed to replace conventional UHMWPE as an artificial joint material. Different molecular weights of ULWPE, ULWPE-200, ULWPE-300, and ULWPE-700 were examined against CrCoMo compared to conventional UHMWPE in multidirectional motion. The wear mechanism was elucidated from the perspective of macroscopic wear behavior and microscopic wear debris characterization. It was found that the morphologies of the ULWPE worn surface were similar to that of UHMWPE, with scratches, burnishing, and protuberances. ULWPE-700 possessed the lowest wear loss at all loading conditions, and the wear loss was 40.3% lower than that of UHMWPE at 3 MPa. Furthermore, wear debris was consistent in morphology and size range but showed differences in quantity, size distribution, and shape distribution. Combined with the wear surface morphology and wear debris analysis, it showed that plastic deformation was the main cause of wear debris formation and the wear mechanisms were adhesive wear and abrasive wear. Moreover, the FBA of ULWPE-700 was 64% lower than that of UHMWPE at 3 MPa, suggesting that ULWPE-700 wear debris had the lowest potential osteolysis. This study provides deeper insight into the bio-tribological behavior and the potential biological activity of ULWPE as an artificial joint material. [ABSTRACT FROM AUTHOR]

Improvement in mechanical properties of fibre-reinforced polymer composites through proper matrix modification has emerged as the significant trend in recent advanced technology. Dispersion of nanofillers in the matrix results in ultra-light weight, high strength, impact resistant and durable structures. In the current investigation, effect of the addition of varying percentages (0, 1, 3, 5 and 7 wt.%) of low-cost nanoclay to the unsymmetrical carbon/glass (C2G8) hybrid composites on mechanical, tribological and low-velocity impact (LVI) behaviour were investigated. Using traditional hand lay-up techniques, nanocomposite specimens were prepared. The results revealed that C2G8 hybrid composite with 5 wt.% loading of nanoclay possessed maximum hardness (35 HV), flexural strength (494 MPa), impact strength (Izod (119.022 kJ m−2), Charpy (563.922 kJ m−2)) and minimum specific wear rate (19.6 × 10−3 mm3 Nm−1) in comparison with other hybrid combinations. LVI test also revealed enhanced energy absorption (112.46 J) for hybrid nanocomposite against plain C2G8 hybrid composite. Furthermore, the damage depth and areas were observed by visual inspection and scanning electron microscope to account for best possible structure–property relationship. Developed hybrid nanocomposite may be considered as a suitable material for various automotive applications. [ABSTRACT FROM AUTHOR]

Friction coefficient depends on various factors or surface characteristics during tribological testing, and this friction coefficient can be modified by altering the properties of one of the two contacting surfaces. It is crucial to monitor the friction coefficient continuously, not only at the conclusion of the test. This research examined the evolution of friction coefficient of silicon nitride (Si3N4) coating and H13 steel over different sliding distances (250, 500, 750, 1000 m). The study assessed surface wear and oxidation through three-dimensional profilometry and SEM/EDX. The findings indicated a reduction in friction coefficient by 22%, a decrease in wear rate by 88%, and a reduction in wear volume by 87% when comparing the silicon nitride coated steel to the uncoated steel. Furthermore, the changes in friction coefficient provided insights into the timing of the complete fracture of the hard coating. [ABSTRACT FROM AUTHOR]

The purpose of this investigation is to see how varying percentages of Graphene Nanoplatelets (GNP) affect the wear behaviour of carbon fibre reinforced epoxy (CFRE) composite. The hybrid nano composites were developed using hand layup process followed by compression moulding. Furthermore, the impact of operational parameters such as load and abrading distance against SiC paper of 220 grit size at a rotational speed of 200 rpm was investigated. It was found that incorporating a considerable amount (up to 0.5 wt. %) of GNP significantly improved the wear performance of CFRE composites. There is increase in wear loss again for 0.75 and 1.0 wt. % GNP. The morphology of developed nano hybrid composites were linked to data patterns on wear volume and specific wear rates. GNP addition up to 0.5 wt. % strengthened the fibre-matrix interface, preventing simple fibre pull-out from matrix/fillers and enabling increased wear resistance, according to worn surface characteristics investigation. [ABSTRACT FROM AUTHOR]

Among the materials used for components subjected to abrasive wear, chromium cast iron, hardfaced layers, martensitic steels and Hadfield steel should be singled out. Each of these types of materials exhibits a different morphology of structure and strength properties. Hadfield steel, characterized by an austenitic microstructure, shows the ability to strengthen the subsurface layers by cold work, while maintaining a ductile core. Hardox steels belong to the group of low-alloy martensitic boron steels. However, it should be noted that increasing hardness does not always translate into low wear values due to a change in the nature of wear. In view of the above, the authors decided to subject selected Hardox steels and Hadfield cast steels in the post-operational condition to abrasive wear tests in the presence of loose abrasive. The study showed that Hardox Extreme steel exhibits the highest resistance to abrasive wear (value of the coefficient kb is equal to 1.39). In the case of Hadfield steel, the recorded values are slightly lower (kb = 1.32 and 1.33), while the above ratios remain higher compared to Hardox 600 and Hardox 500 steels. The main wear mechanism of high-manganese steels is microploughing, plastic deformation and breakouts of larger fragments of material. In the case of Hardox 450 and Hardox 500 steels, the predominant wear mechanisms are microploughing and breaking out of material fragments. As the hardness of the steel increases, the proportion of wear by microcutting and scratching predominates. [ABSTRACT FROM AUTHOR]

Polyurethane coatings are widely used as protective layers against wear, mainly abrasive wear. They have recently been applied to surfaces exposed to erosive wear, such as wind turbine blades. This study investigated the abrasive and erosive wear of polyurethane elastomeric coatings with hardness values of 55 ShA, 75 ShA, and 95 ShA. The abrasive wear test was carried out using loose abrasive grains. The erosive wear test was carried out using a pressurized stream of gas containing abrasive particles. Both tests were carried out using aluminum oxide grains of five different sizes to evaluate the effect of particle size on wear behavior. Microscopic and profilometric analyses of the surface of the wear tracks were carried out. The mechanism of abrasive and erosive wear of polyurethane elastomeric coatings was determined. The results of the tests show a non-linear dependence of abrasive and erosive wear on the grain size. Furthermore, polyurethane elastomer coatings with a higher hardness exhibit a lower abrasive wear resistance but higher susceptibility to erosive wear. These findings provide insight into the trade-offs between hardness and wear performance, offering practical guidance for selecting polyurethane coatings in applications requiring resistance to combined abrasive and erosive wear. [ABSTRACT FROM AUTHOR]

Aluminum alloys are widely used in various industries due to their as low density, high strength-to-weight ratio, and good corrosion resistance. However, their wear resistance is often inadequate for certain applications. Utilization of industrial waste materials, such as iron slag, as reinforcement in aluminum alloy matrix composites offers a sustainable approach to material development and waste management. The utilization of industrial waste materials for aluminum alloy matrix composite fabrication offers a waste utilization to material development. The loading of this reinforcement varied from 0 to 15 wt.% and different particle size range (220-140, 140-70, and 70-0 µm). A microscopic analysis indicated that the iron slag particles are spread uniformly inside the metallic matrix. There is also a reduction in the size of primary silicon, as well as morphological changes (acicular to globular shape). The wear behavior was calculated using a pin-on-disk wear set up in accordance with ASTM G99 standard. The composites were employed to dry sliding wear test under various operating conditions such as applied pressure (0.2–1.4 MPa), and sliding distance (0–3000 m). The 15F composite outperformed all other composite samples in terms of wear rate under all working conditions. When compared to the base alloy, it demonstrated a remarkable 67% drop in steady state wear rate. The enhancements in wear performance for the 15F composite were attributed to the effects of Fe slag reinforcement. The inclusion of iron slag particles induced strong interfacial bonding between matrix and reinforcement particles improving the durability of the mechanical mixed layer developed during relative motion. Importantly, the wear rate parameters of the 15F composite were similar to those of the brake drum material used in commercial applications. This emphasizes the composite suitability for usage in a variety of automobile components. [ABSTRACT FROM AUTHOR]

Highlights Response surface methodology is suitable for DEM input parameter optimization. Soil reaction forces reduced at velocity ratios greater than one (1.2-3.9). Vibration reduced soil reaction forces at the target depth of 350 mm by 70%. In general, soil reaction forces increase with speed but decrease with frequency. Abrasive wear predominantly occurred at the tool’s cutting section. The discrete element method (DEM) and response surface methodology (RSM) were used to determine the input parameters and combination of operational factors required for optimizing the Jerusalem artichoke (Helianthus tuberosus L.) harvesting tool in cohesive soil. The DEM soil model consisted of particles with different radii in three shapes calibrated using angle of repose and cone penetration data. Compared with data from a soil bin subsoiler evaluation, the DEM model showed acceptable relative errors for draught force (6.7%), vertical force (4.5%), and furrow width (9.3%). The effects of operational factors, including forward speed, vibration frequency, and amplitude, on response variables such as draught and vertical forces, drawbar power, and abrasive wear were analyzed for three harvesting shovels (S-shape, step-shape, and fork-shape). The ratio of vibratory speed to forward speed (velocity ratio, Vr) was used to analyze the combined effect of the factors. The operational factors significantly affected all the response variables (p<0.05). At Vr > 1 (1.2-3.9), soil reaction forces and drawbar power were considerably reduced. The optimal parameters for minimizing the response variables were 2.5 km h-1 forward speed, 14.5 Hz frequency, 30 mm amplitude, and S-shape shovel at Vr = 3.9. The minimum draught force, vertical force, drawbar power, and Archard wear depth were 4.64 kN, 0.41 kN, 2.64 kW, and 2.36 mm, respectively, at an operating depth of 350 mm. Operating in vibratory mode reduced draught force by 54% with the full width of the implement. Future work should include Jerusalem artichoke tubers in the simulation and experimental validation. [ABSTRACT FROM AUTHOR]

Material selection is the main challenge in the drone industry. In this study, hardness, abrasive wear, impact resistance, tensile strength, and durability (frost resistance and accelerated ageing) were identified as important characteristics of drone materials. The additive manufacturing technology was used to produce the drone leg specimens and prototype. The suitability of PETG as a primary filament material in the design of the drone leg was investigated. Nine series were printed with different raster lines (0.1, 0.2 and 0.3 mm) and infill densities (30, 60 and 90%). Printed specimens were annealed in salt and alabaster, as well as immersed in liquid nitrogen. Series with raster line-infill densities of 0.1–30, 0.3–30, 0.1–90 and 0.3–90 were identified as the most interesting ones. Thermally treated specimens had better mechanical and durability properties, and infill density was found to be the most important printing parameter. Specimen annealed in salt with a raster line of 0.1 mm and infill density of 90% had the best results. Since ABS is the most common material used for drone leg production, its properties were compared with the PETG specimen, which showed the best properties. The potential of PETG as an alternative material was proven, while the flexibility, productivity and suitability of the leg drone design were additionally confirmed. [ABSTRACT FROM AUTHOR]

The fretting wear behavior of H62 brass against GCr15 steel under prestressed conditions was studied using a self-developed fretting wear device in this study. The effects of normal loads, prestresses, fretting frequencies, and fretting movement amplitudes were studied. Simultaneously, the changes in the coefficient of friction, depth of the wear scar, surface morphologies of the wear scar, and wear mechanisms were analyzed. Experimental results showed that the coefficient of friction decreased as the normal loads and prestresses increased and increased as the fretting frequencies and fretting movement amplitudes increased. The depth of the wear scars clearly increased as the normal loads and prestresses increased and decreased as the fretting movement amplitudes increased. The oxygen contents slightly increased in the annular area of the wear scars. The main wear mechanisms of H62 brass against GCr15 under different fretting parameters used in this study were abrasive wear, adhesion wear, and local spalling. [ABSTRACT FROM AUTHOR]

A system and method have been developed for rapid testing of the abrasive wear. In this method, five samples of different materials, with different coatings, are tested at the same time. Clarity of the results is ensured during the experiments. [ABSTRACT FROM AUTHOR]

Natural fiber reinforced composites are easy to decompose in nature compared to synthetic fiber reinforced composites. However, due to environmental effects, natural fibers cannot maintain their properties for a long time. This situation has led researchers to search for natural but non-degradable materials. Kaolin is one of the most abundant minerals in nature and is an easy material to obtain. This study investigated the use of kaolin as a potential natural additive for polymer composites. In this direction, different proportions by weight of kaolin were added to two different polymer matrices (polyester and polyvinylester) materials. Mechanical tests were performed on the samples, and a series of tests were carried out to understand the acid resistance, wear resistance and water absorption properties of the samples. Also, SEM images of the fracture surface, wear surface, and surface exposed to the acidic solutions were taken and examined. According to test results, kaolin improved compression strength while reducing tensile and flexural strength. However, serious improvements have been achieved by nearly 45% and 115% in the tensile modulus and nearly 84% and 218% in the flexural modulus of polyester and polyvinylester composites, respectively. Also, kaolin improved acid resistance and wear properties and reduced the water absorption rate of the composites. [ABSTRACT FROM AUTHOR]

Lightweight materials with better resistance to sliding wear are prominent candidates for automobile brake drums, clutch pads and cylinder block applications to facilitate fuel economy. This attempt is reserved to cater to materials with higher tribological quality needs. Less dense foamy pumice stone particles were involved in three different percentages (5, 10, and 15 wt%) to reinforce lightweight AZ31 Mg alloy. A stir-assisted squeeze casting technique was pursued to process the composite and refine the grain structure. A phase detection, elemental mapping and microstructure study were done through X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and scanning electron microscopy (SEM), respectively. An experimental dry sliding wear scrutiny was administered using a pin-on-disc apparatus by considering: (i) ambient and elevated temperature environments and (ii) three different levels of loads. The results reveal a significant drop in wear loss and a frictional coefficient for 15% pumice-loaded composite than the base alloy. Post-wear examination acknowledges the fact that the ambient temperature wear is governed by adhesive-abrasive wear and high temperature is by abrasive wear mechanisms. Worn-out scrutiny authenticates the presence of oxide layers and their role in lubrication. A comparative study with previous works upholds the novel magnesium composite is the right candidate for the mentioned automobile applications.

In materials science, steel boration is a promising type of thermochemical diffusion process, the purpose of which is the introduction of hard and wear-resistant boride particles into the surface layers of the metal. The main disadvantage of boration is the fragility of borated layers, especially boride. Currently, there are promising methods for the formation of a composite structure, which are based on the treatment of surface layers of steels with concentrated energy flows (laser, electron beam and plasma). The work includes studies of microstructure, hardness measurements, analysis of phase composition, and determination of chemical composition in local locations, wear tests under various conditions, and adhesion testing of the coatings obtained after plasma boration. As the degree of alloying of the molten layer decreases in the direction from the surface to the base metal, zones of overeutectic, eutectic and pre-eutectic types with a different combination of structural components are formed. The material obtained after borating a mixture of 40% B + 10% Fe is characterized by the highest level of microhardness, which is 1000...1300 HV. The highest results in friction tests are provided by boration of a powder mixture of 40% B + 10% Fe.

SiMo ductile irons, typical heat-resistant materials, are subjected to varied wear environments during operation in high-temperature applications. SiMo ductile iron castings of different thicknesses were cast in investment and greensand molds, achieving a wide range of cooling rates. The present work aims to investigate the effect of the cooling rate and alloying elements (Cr, V, and Ni) on the microstructure and the abrasive wear behavior of these grades of SiMo ductile iron at high-temperature 700 °C under different loads. Thermodynamic calculations were used to propose the phase diagrams, critical transformation temperatures, and phase volume fractions in all SiMo alloys by using the Thermo-Calc software then verified by and Differential Scanning Calorimetry (DSC). The microstructure of unalloyed SiMo ductile cast iron consists of graphite nodules and carbides embedded in the precipitates at the grain boundary regions in a ferrite matrix. The alloyed SiMo microstructure contains nodular graphite and the carbides promoted by the alloying elements (Cr and V). The alloyed SiMo alloys exhibit higher wear resistance than unalloyed ones. These wear results support that the microstructure plays a chief role in wear loss. The combination of M6C, VC, and M7C3 carbides embedded in a ferrite-pearlite matrix (alloyed SiMo) seems to be more resistant to wear than the ferritic matrix with lamellar pearlite and eutectic M6C carbides (unalloyed SiMo). [ABSTRACT FROM AUTHOR]

Aluminum matrix composites reinforced with ceramic particles are widely used in parts and components operating under severe abrasive friction and wear conditions. This work investigates the effect of the particle size and the amount of B4C and SiC reinforcements ranging from 0 to 25 wt % in the initial powder mixture on the microstructure, micromechanical properties, and abrasive wear resistance of aluminum matrix composites. It is shown that B4C and SiC reinforcement particles contribute to the refinement of the aluminum matrix. Micromechanical properties determined by instrumented microindentation indicate that the hardness of the composites exceeds the hardness of sintered aluminum, and Al–25% SiC composite has the highest mechanical load resistance compared to other composites studied. Pin-on-plate wear tests of samples sliding against fixed electrocorundum grains revealed the greatest abrasive wear resistance of Al–25% SiC and Al–12.5% В4С–12.5% SiC composites. The minimum resistance was observed for Al–25% B4C. These materials demonstrate adhesive and abrasive wear behavior with the formation of characteristic wear grooves and tear pits. [ABSTRACT FROM AUTHOR]

Bandsaw blades are typical band-shaped cutting tools that are characterized by their low stiffness and micro-level cutting depth, resulting in distinct wear mechanisms compared to rigid cutting tools. In this study, the wear curve and wear mechanisms of the bandsaw tooth during the bandsawing of Cr12MoV cold-working steel were investigated. The tool life was divided into two stages: a rapid wear stage (Stage I) and a homogeneous wear stage (Stage II). In Stage I, the wear was dominated by chipping, although multiple wear mechanisms were found due to their relatively low manufacturing accuracy compared to rigid cutting tools, which resulted in remarkable differences in the cutting depth of each tooth. In Stage II, abrasive and adhesive wear were the primary wear mechanisms instead of chipping, which was related to the microstructure of Cr12MoV. Furthermore, methods for increasing bandsaw performance were proposed, based on the tooth wear mechanisms. [ABSTRACT FROM AUTHOR]

This study investigated the effect of abrasive water jet (AWJ) kinematic parameters, such as jet traverse speed and water pressure, abrasive mass flow rate, and standoff distance on the surface of BK7. Nozzle A reinforced with a 100 nm particle-sized coating of titanium alloy has more wear resistance compared to Nozzle B coated with nothing. Through analysis of variance and measurement of BK7 surface quality, it is concluded that the grooving and plowing caused by abrasive particles and irregularities in the abrasive water jet machined surface with respect to traverse speed (3, 7.2, 7.8, and 9 mm/min), abrasive flow rate (7 L/min and 10 L/min, 80 mesh) and water pressure (2 and 3 MPa) were investigated using surface topography measurements. The surface roughness (15.734 nm) of BK7 results show that a nozzle coated with titanium alloy has more hardness, which protects BK7 undamaged and super-smooth. The values of selected surface roughness profile parameters—average roughness (Ra) and maximum height of PV (maximum depth of peak and valleys)—reveal a comparatively smooth BK7 surface in composites reinforced with 2% titanium alloy in the nozzle weight at a traverse speed of 7.8 mm/min. Moreover, abrasive water jet machining at high water pressure (3 MPa) produced better surface quality due to material removal and effective cleaning of lens fragmentation and abrasive particles from the polishing zone compared to a lower water pressure (2 MPa), low traverse speed (5 mm/min), and low abrasive mass flow rate (200 g/min). [ABSTRACT FROM AUTHOR]

Developing a technology that increases the service life of valve seats in CNG/LNG-powered vehicles requires the appropriate selection of material and its application technology. Commercially used valve seat materials show accelerated wear under operating conditions, especially in natural gas vehicle engines. The authors developed a new material and technological concept to protect the valve seat in CNG/LNG-powered vehicles. Two materials were used in the research: Stellite 6 alloy and Fe 3 Al intermetal. A commonly used material for valve seats of combustion engines is Stellite 6. The Fe 3 Al is the new proposed material coating for the protection of the valve seats of internal combustion engines. The article compares the abrasive wear resistance of these materials. The abrasion tests were performed on a T-11 pin-on-disc tester, and the counter-sample was steel S235JR. The test conditions were similar to those prevailing during the operation of the valves in the head of the internal combustion engine, without the influence of temperature. The results indicate that the Fe3Al intermetallic compound is characterised by a lower coefficient of friction and wear intensity than Stellite 6. The results of exploitation tests confirm that the Fe 3 Al phase is a prospective material to be used as a protective material on the valve seat of vehicles. The authors made a mathematical model for the wear of the newly created surface layers and proposed hypotheses regarding the wear mechanisms of these layers. [ABSTRACT FROM AUTHOR]

Polymeric materials are widely used in aerospace, biomedical, marine, and agricultural applications due to their viscoelasticity and corrosion resistance. Polymeric materials fail due to wear during their service life, so studying their wear behavior is essential to control and predict their service life. This paper summarizes the progress of water lubrication research as well as experimental studies on the wear of polymeric materials under aqueous conditions. The effects of lubrication conditions, material formulation ratios, load, sliding speed, impact angle, abrasive particles, and temperature factors on the wear behavior of commonly used polymeric materials ideal for water lubrication (NBR, SBR, NR, EP, polyethylene, and their composites, etc.) are summarized in terms of the three most frequently occurring forms of wear, namely, two-body wet sliding wear, two-body erosive wear, and three-body wet abrasive particle wear. The results show that the mechanical properties, such as hardness, can be effectively changed by altering the formulation ratios of the materials, and the hardness and hydrophilicity of the formulations can further affect the wear and lubrication. In general, the coefficient of friction and the wear rate decrease with the increase in hardness, and the increase in temperature leads to the localized lubrication failure and the aging of the materials, which in turn leads to the intensification of wear. Among the working condition factors, load and sliding speeds are the most important factors affecting the wear, and the wear rate increases with the increase in the load and sliding speed; in contrast, the three-body wet abrasive wear is more obviously affected by the load. In the study of the impact angle effect, the overall trend of the erosion wear rate with the increase in the angle shows the first rise and then fall, the maximum value is mostly concentrated in the 45–60° between. Usually, the increase in the abrasive particle size can make the wear rate increase. Overall, the three-body wet abrasive wear of the rubber material wear rate shows first an increase and then a decrease. The research in this paper provides theoretical support and reference ideas for the tribological study of polymer materials in the water environment and puts forward the outlook for future water lubrication and material improvement of the research directions and applications. [ABSTRACT FROM AUTHOR]

The current trend is the ecological consciousness of replacing synthetic fibers with natural fiber. However, several restrictions exist on using natural fibers/fillers, including compatibility, hydrophobicity, and locality. The natural material chosen for the present investigation, Acacia nilotica, is short and cylindrical; the same has been used as reinforcement after being chemically treated with silane and grinded into fillers in the present study. Grinded silane-treated A. nilotica fillers were added in a range of 0, 2, 4, and 6 weight percent to the epoxy matrix. Conventional hand layup was used to manufacture composite materials using epoxy resin and hardener. The manufactured composite's tribological properties were evaluated according to ASTM G99-17 using the pin-on-disk machine under two-body abrasive wear conditions. L-16 orthogonal arrays were used to conduct the research. Load, sliding distance, and material were the process input parameters, and the results were evaluated using the Specific Wear Rate (SWR) and Coefficient of Friction (COF). Analysis of variance (ANOVA) was used to analyze the significant variables. EDAS was used to optimize the output. The abraded surfaces were finally studied using worn surface morphology. According to the findings, silane-treated A. nilotica filler is a new and promising resource as a sustainable raw material for reinforcement in polymer composites manufacturing lightweight materials. Results revealed that the optimized values were 6 wt%, load at 20 N, and sliding distance of 225 m. SWR values decreased by 61.2%, and COF values decreased by 34.3% in the case of 6 wt% composites compared to the unreinforced fiber composites. The rank of the sample was assigned according to performance by the EDAS process. [ABSTRACT FROM AUTHOR]

Agglomerated Diamond (AD) abrasives were prepared using a ceramic bond and microfine single-crystal diamond (SCD). Lapping experiments were conducted to investigate the lapping performance and wear mechanisms of AD abrasives. The processing mechanisms of AD abrasives on sapphire wafers were revealed through friction and wear experiments and Power Spectral Density (PSD) methods. The results show that compared to W3 SCD, the material removal rate (MRR) of AD abrasives increased by 89.1 %, while the surface quality of the processed sapphire wafers was similar. Under the polyurethane lapping discs, AD abrasives achieved an MRR of 3.62 μm/min and a surface roughness (Ra) of 15.3 nm. The sapphire surface lapped with AD abrasives was the smoothest, with the PSD curve of the surface profile showing less noticeable layering, and the PSD values of the surface profile in the same frequency domain space were relatively the lowest. During the lapping process, the wear mechanisms of AD abrasives were identified as abrasive wear and micro-fracture. Under the impact and compression between the workpiece and the lapping discs, the fine SCD particles on the surface of the abrasives would wear and detach, and the network structure of the ceramic bond would fracture, exposing the fine SCD particles embedded in the bond to the surface, thus renewing and self-sharpening the cutting edges. • Agglomerated Diamond (AD) abrasives with multi-edge cutting and micro-fracture characteristics were prepared and used for loose-abrasive lapping of sapphire wafers. • The lapping properties and wear mode of AD abrasives were investigated. • The processing mechanism of AD abrasive is revealed through friction wear test and Power Spectral Density (PSD) analysis method. [ABSTRACT FROM AUTHOR]

Chemical strengthening of glass represents a standard technology for fabricating damage‐resistant protective covers. Still, little attention has been paid to modifications in the tribological properties of ion‐exchanged glass surfaces. This work reports on scratch testing of a chemically strengthened alkali‐borosilicate thin glass. Diffusive Na+/K+‐ion exchange produces a residual surface compressive layer with compressive stress of 200–340 MPa and layers depths between 16 and 50 µm, depending on exchange temperature and treatment time. This leads to notable changes in the surface mechanical properties, such as an increase in surface Young's modulus, indentation, and scratch hardness. Surprisingly, the Na+/K+‐ion exchange is shifting the onsets of scratch‐induced microcracking and microcracking to lower normal loads. The accelerated buildup of lateral indentation stress in glasses with high scratch hardness was found to be responsible for the lower threshold loads of microcracking and abrasive wear in chemically strengthened alkali‐borosilicate thin glass. [ABSTRACT FROM AUTHOR]

With the escalating industry-wide requirement and based on the inherent properties, recently the polymeric composite is in more demand for tribo-application. Again, the development of eco-friendly material by inclusion of materials derived from natural resources is also becoming one of the promising areas of the interest. In this current study, an agricultural residue like pistachio shell particulates (PSP) is used as bio-filler to develop polymer matrix composites for tribo-application. The polyester matrix test specimens are fabricated with variation of PSP filler concentration ranging from 0 to 7 wt% by the hand lay-up method. The influence of filler content on both mechanical and sliding wear performances of the composites is studied. As per ASTM standard, several tests like tensile, flexural, impact and micro-hardness test have been carried out. To observe abrasive wear response of the developed composite, the dry sliding wear test has been conducted on a pin-on-disc wear tester in accordance with ASTM standard under five different normal loads, sliding distances and three distinct sliding velocities. The findings revealed that the mechanical performances of the composites are enhanced with the increase in the PSP filler concentration. Optimum properties such as hardness of 13 HV, tensile strength of 36.55 MPa, flexural strength of 43.66 MPa and impact strength of 16.36 kJ/m2 are obtained at 5 wt% reinforcement of PSP filler. Again, an improvement in sliding wear resistance by 39.57% is also noticed. During the examination of worn surface by scanning electron microscope (SEM), the appearance of cracks and the creation of grooves at the lower filler loading and formation of wear debris are noticed at the higher filler loading. [ABSTRACT FROM AUTHOR]

The service life of mining equipment is determined by the durability of only a few, the most responsible parts. Ladles, which are operated in severe conditions of hydroabrasive wear combined with shock loads, are the most fast-wearing element of ball grinding mills. Interrepair cycles of this equipment are determined by the durability of the ladles. It is shown that heat treatment is the most important factor affecting the size and distribution of structural components of steel, which largely depend on its mechanical and operational properties.On the basis of the constructed diagram of the isothermal decomposition of supercooled austenite for modified 40Cr(casting) (Standard of Ukraine) steel, the possibility of obtaining, during continuous cooling in various sections, castings of ''ladles'' of bainitic structure, in which, after high tempering, a ferrite-cementite mixture with a spherical shape of cementite is formed, providing a high complex of physical and mechanical properties and wear resistance. The developed resource-saving technology of thermal treatment of ladles, which consists in intermittent quenching followed by tempering, made it possible to increase their operational durability by approximately 2 times compared to ordinary 40Cr(casting) steel and increase the maintenance intervals of ball grinding mills.

The primary objective of the current study is to enhance the damping capability of polylactide (PLA)/jute fiber composites without sacrificing their strength and stiffness. With this objective, multiphase composites were fabricated with silane-treated jute fiber and nitrile butadiene nano rubber modified polylactide. The mechanical and damping behaviors of the developed multiphase composites were evaluated. The modulus and strength of the composite were effectively increased by the silane-treated jute fiber. However, the impact strength and damping capability also decreased with chemical treatment of the jute fiber. Conversely, PLA was successfully toughened by the addition of rubber nanopowders, leading to significant improvements in the impact strength and damping ability of the composites. This improvement was achieved with minimal compromise in terms of stiffness, strength, and environmental appeal. In addition, modification of the PLA matrix with rubber nanopowders also resulted in the enhancement of abrasive wear resistance.

The article presents the test results on the technology of surface hardening of castings from unalloyed and low-alloy nodular cast iron using the method of surface heat treatment, i.e., induction surface hardening and methods of thermochemical treatment, i.e. gas nitriding, nitrocarburizing, and nitrocarburizing with oxidation. The scope of research included macro- and microhardness measurements using Rockwell and Vickers methods, respectively, as well as metallographic microscopic examinations using a light microscope. Furthermore, abrasive wear resistance tests were performed using the pin-on-disk method in the friction pair of nodular cast iron – SiC abrasive paper and the reciprocating method in the friction pair of nodular cast iron – unalloyed steel. Analysis of the test results shows that the size and depth of surface layer hardening strongly depend on the chemical composition of the nodular cast iron, determining its hardenability and its ability to create diffusion layers. Medium induction surface hardening made it possible to strengthen the surface layer of the tested nodular cast irons to the level of 700 HV0.5 with a hardening depth of up to approximately 4000μm, while various variants of thermochemical treatment provided surface hardness of up to 750 HV0.5 with a hardening depth of up to approximately 200μm. Furthermore, induction surface hardening increased the resistance to abrasive wear of nodular cast iron castings, depending on the test method, by an average of 70 and 45%, while thermochemical treatment on average by 15 and 60%.

To improve the roughness prediction accuracy of Al2O3-based ceramic insulation coating on bearing surfaces, a method based on the spectral confocal principle was proposed for measuring the surface of grinding wheels and quantifying the characteristic parameters of abrasive particles. The abrasive characteristic parameter K of the grinding wheel surface, the grinding wheel line speed vs, the workpiece feed speed f, the cutting depth ap, and the normal grinding force F were taken as input parameters. A BP neural network prediction model of workpiece surface roughness, which directly reflects the time-varying state of the grinding wheel surface, was established. The prediction performance of the network model was verified using known grinding samples and four groups of unknown samples after grinding wheel wear. The results show that the predicted roughness results of the BP network model with known samples are consistent with the actual roughness results in terms of regularity and numerical values, with network output errors are all less than ± 0.04 μm. The network prediction accuracy for the four unknown samples decreases, but the absolute value of the maximum relative error does not exceed 20.00%. The neural network prediction model, which includes the characteristic parameters of abrasive particles on the grinding wheel surface , can be used to predict the roughness of Al2O3-based ceramic insulation coating on the bearing surface under the time-varying state of abrasive wear on the grinding wheel. It also demonstrates a certain generalization ability for unknown samples.

This article presents the results of abrasion wear resistance tests of wear-resistant steel and surfacing under laboratory conditions and natural operation. Abrasion wear resistance determined on the basis of the study by determining geometrical characteristics of the alloying additives using computer image analysis methods, as well as examining the changes occurring on the surface of the workpieces and their wear intensity. Based on the results obtained from laboratory tests, it was noted that AR steel exhibited 14 times greater wear than the padding weld. This wear is affected by alloy additives, which, for the padding weld, are chromium additives. The microstructure image shows that soil mass had a destructive effect mainly on the matrix of the material, whereas in the areas with high concentrations of chromium precipitates, this effect was significantly weaker. The operational test results showed that within the area of the tine subjected to hardfacing, the material loss was lower than that for the same area of the tine in the as-delivered state. For the hardfaced tine, a 7% loss of volume was noted in relation to the operating part before testing and following the friction process. However, for the operating part in the as-delivered state, this difference amounted to 12%. [ABSTRACT FROM AUTHOR]

The wheel set of a rail vehicle with a disc brake is the basic assembly of a rail vehicle exposed to abrasive wear. From the operational point of view, the wear process of the wheels and brake discs is uneven, which for the carrier involves switching off the vehicle, once when the maximum wear of the discs is reached and again when the wheels wear out. The process of both untying the wheel set from the bogie, dismantling the wheels and discs from the axle is a time-consuming and expensive process, which consequently affects the exclusion of the vehicle from planned traffic. In the article on the basis of brake disc wear results, 3 concepts of bogie management were proposed. The first concerns the bogie rotation, the second and third concepts concern the exchange of bogies with and without rotation. Using the MUZ multi-criteria programming method, the concepts were evaluated and the best one was selected taking into account the evaluation criteria. The aim of the article is to present concepts that reduce the wear of discs brake systems in a multi-unit traction unit using bogie migration under the vehicle. [ABSTRACT FROM AUTHOR]

As a contribution of recycling of polymers in the automotive industry, recycled polyvinyl butyral (rPVB) from automotive windshields is being explored as a solid lubricant reinforcement for improving lubricity of engineering polymers. This work aims to evaluate the tribological behavior (coefficient of friction [CoF] and wear resistance) of polyamide 6 (PA6) and glass-fiber-reinforced polyamide 6 (PAGF) blended with rPVB as solid lubricant under two-body and three-body abrasive conditions. The different polymer blends were produced by adding recycled polyvinyl butyral (rPVB) into a matrix of either a commercial polyamide 6 (PA6) or a commercial 30% glass-fiber reinforced polyamide 6 (PAGF). The tribological tests were conducted in an instrumented microabrasion tester for generating wear and measuring the coefficient of friction (CoF) in both dry and microabrasion conditions. In the dry condition, rPVB was effective in reducing the CoF for both PA6 and PAGF. Two-body abrasion was found as the predominant wear pattern in the dry condition. On the other hand, in the microabrasion condition, the additions of rPVB were not totally effective since they produced a wear resistance increase for PAGF but a reduction for PA6, which was ascribed to a notable decrease in toughness for PA6 when adding rPVB. Well-defined plowing traces and several SiC particles embedded in the scars were the predominant patterns in all the materials. In both PA6 and PAGF, CoF increased with the rPVB additions. [ABSTRACT FROM AUTHOR]

The results of the study of patterns of destruction and their influence on the wear resistance of low-alloy steel 65G in the unstrengthened state, as well as after strengthening by thermal and electroerosion treatment during movement in soils of different fractional composition, are presented. It has been confirmed that under such conditions the phenomenon of the presence of a critical size of abrasive particles (CPS) is realized on the wear surface. The role of the geometric size of the particles in the formation of the wear resistance of steel consists in the regulation of active deformation and fatigue phenomena on the wear surface by changing the level of force acting on it. The influence of the fractional composition of the soil on wear resistance is carried out through the rheological fatigue parameter in the following dependence: the greater the rheological-fatigue parameter, the higher the wear resistance of steel. Therefore, the mechanical component of the contact interaction is decisive in the strength basis of the wear mechanism. Therefore, when choosing a brand of low-alloy steel for the manufacture of machine parts intended for operation in soils of different fractional composition, it is necessary to be guided by its ranking according to the rheological-fatigue parameter. The role of the fractional composition of the soil in the formation of the rheological- fatigue parameter is carried out mainly through the cyclic viscosity of deformation in the sublayer of nonlinear effects in the vicinity of the crack tips of the surface layer in the following dependence: the higher the cyclic viscosity, the lower the rheological-fatigue parameter of steel. The stress that is cyclically repeated during abrasive wear causes in the sublayer of nonlinear effects in the vicinity of the crack tips of the surface layer two opposite phenomena that occur simultaneously: strengthening and weakening. At the same time, the action of the weakening process in soils of different fractional composition is more effective than strengthening. In the region of the subcritical geometric dimensions of the abrasive particles, the intensity of hardening is significantly reduced due to the increase in the effectiveness of the hardening action due to the additional contribution of dispersion hardening. However, this does not entail qualitative changes in the wear process. [ABSTRACT FROM AUTHOR]

Microstructural heterogeneities of an ASTM A128 grade C steel subjected to heat treatments and their effect on abrasive wear behavior were investigated. The heat-treatment process involved different austenization times at 1050 °C and quenching media. To characterize the effects of heat treatment on the material's microstructure and mechanical behavior, two microscopy techniques were used: optical microscopy (OM), and scanning electron microscopy (SEM). The chemical composition of the material was obtained using X-ray fluorescence (XRF) optical emission spectrometry. The variation in carbide composition was evaluated using X-ray Energy Dispersive Spectroscopy (EDS). To characterize the mechanical behavior of the steel, hardness measurements and abrasive wear tests were performed after homogenization annealing and quenching treatments. The results showed that the heat-treated samples developed a heterogeneous microstructure, with the presence of austenitic grains and Martensite around the surface of the samples induced by decarburization in both the protected and unprotected specimens. The specimens with lower decarburization presented less formation of Martensite and precipitated carbides, resulting in lower hardness values and higher abrasion resistance (solution treatment at 1080 °C for 1 h + sand protection + brine quenching). [ABSTRACT FROM AUTHOR]