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For the abrasive wear of hard/soft dynamic seals, simplified uniform hardness research have been difficult to support the technology development at this stage. Therefore, the tribological behavior of non-uniform hardness particles was investigated. The results showed that the particles breakage and non-uniform effect combined to influence wear level. This caused the damage to the interfaces by the particles not to be the result of an average of both the hardness. For a clearer explanation, the influence of non-uniform hardness effect was discussed through a combination of the model and the phenomenon. The significance of this work was to enrich the existing understanding of the hardness effect and thus to provide suggestions for improving the wear resistance of hard/soft dynamic seals. [ABSTRACT FROM AUTHOR]

Abrasives play a critical role in the polish process of natural stone. Therefore, they can significantly affect the performance of polishing. In the thematic literature, there is no detailed study investigating the effect of abrasives from two different manufacturers in the same form on the natural stone polishing performance and wear characteristics of abrasive grain. The current study aims to fill this gap. Two abrasives are used on natural stone polishing process. Marble samples are polished in the same abrasive series, at constant belt and head pressure. Polishing performances of the abrasives are investigated based on surface roughness, surface gloss and the wear mechanism of abrasive grain. The study revealed that the Abrasive B present higher polishing performances in terms of the surface roughness and gloss on marble sample. The SEM analysis presented that the wear mechanisms of SiC grain are mainly attributed to abrasive wear, fracture wear and plucked out of abrasive. Additionally, it is concluded that polishing performance of the natural stone is highly affected by abrasive grain shape and grain distribution. [ABSTRACT FROM AUTHOR]

The evolution of transient two-body abrasive wear was investigated using a machine vision system. In the early stages, abrasives with sharp tips produced abrasive wear patterns characterized by isolated elongated grooves. As the abrasive wear progressed, these grooves disintegrated into shorter grooves owing to the overlap of existing and newly formed abrasive wear patterns. This increased the optical image features that correlated with both roughness and mass loss. The relationship between optical image features and mass loss was analyzed from the perspective of abrasive wear theory, and the transition points in the relationship was detected by Kalman filtering. Furthermore, a data-driven framework was developed to predict spatiotemporal variations in surface conditions and the associated optical image features. [ABSTRACT FROM AUTHOR]

(1) In recent years, an increase in the available functionality of non-ferrous alloys has been observed based on the modification and optimization of their chemical composition. This study investigated the effect of Sr addition on the structure and properties of hypereutectic Zn–Al–Cu alloys. The objective was to determine how a modification with Al–Sr master alloy affects the crystallization kinetics, microstructure, hardness, and abrasive wear resistance and whether the modification of the phase composition reduces the corrosion resistance. (2) The total influence of strontium was determined based on the microstructure, phase composition, and derivative curve changes of the tested Zn–Al–Cu alloys with added Sr. Optical microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to analyze the influence of chemical and phase composition, and thermo-derivative analysis (TDA) was used to investigate the crystallization kinetics of zinc alloys with different chemical compositions. (3) Sr modification caused the formation of primary Al2Sr phases in the Zn alloy and also secondary Zn13Sr and Al4Sr phases (depending on the melting temperature of the alloy). (4) The primary and secondary intermetallic phases with strontium increased the hardness by approx. 20% and the abrasion resistance by approx. 7.5%. [ABSTRACT FROM AUTHOR]

The aim of these in vitro studies was to determine and compare the mechanical and tribological performance of two commercially available thermoplastic materials, namely BioHPP and Biocetal, used in dental prosthetics. In order to perform the comparative tests of both materials, the dog-bone shaped samples were formed by an injection molding process as in standard polymer materials research, wherein Biocetal samples constituted the research group, and BioHPP samples served as a control group. In the presented studies, their mechanical parameters were reported and analyzed: namely, Shore's hardness, unnotched impact strength, tensile strength, flexural strength, as well as abrasive wear resistance, obtained within appropriate tribological and mechanical tests. The Shapiro–Wilk test, Q–Q plot analysis, Grubbs test and Student's t-test (p < 0.05) were used to statistically evaluate the results. The experimental results revealed that BioHPP material is characterized by higher hardness, impact strength, bending strength, and also lower "wet" abrasion wear if compared to Biocetal performance. However, it is subject to higher abrasive wear under "dry" conditions and reveals higher stiffness as well as lower ability to deform, which could affect a patient's comfort during application. BioHPP, despite being a high-performance polymer material, also has some drawbacks that may affect the poorer long-term use of dentures in people producing less saliva. [ABSTRACT FROM AUTHOR]

Steel and aluminum alloys are used to manufacture the bodies of bulk material handling machines. The aluminum body enables a higher load mass and thus reduces transport costs. However, the greater abrasion of aluminum alloys leads to more frequent repairs to the underside of the body, as the abrasion parameters of aluminum are lower. This study, which used three different methods to evaluate abrasive wear (erosive/impact wear, abrasive wear in the mass of the free abrasive and abrasion test according to ASTM G65), showed that the most significant influence on the wear of 3004 series aluminum is the grain size of the abrasive. Only under erosive/impact wear conditions with abrasive particles of 2.0–5.0 and 5.0–8.0 mm is aluminum competitive with Hardox 450 in terms of volumetric wear, with aluminum exhibiting 1.3–1.4 times the wear rate of steel. Tests on the abrasive mass of the grinding fraction in question have shown that the volumetric wear of aluminum is 0.2–2.3 times higher at very low contact loads. In contrast, aluminum wears 7.5 and 4 times more than steel in the ASTM G65 test (0.1–0.4 mm fraction) at low and medium contact loads. Only in exceptional cases is the aluminum floor of bulk material handling equipment competitive with hardened steel in terms of wear intensity. [ABSTRACT FROM AUTHOR]

The processes of rock excavation and processing involve intense mechanical stresses on cutting, displacing, and transporting tools, inevitably leading to the phenomenon of dry friction wear. The factors influencing the intensity and mechanisms of wear are complex and interdependent, being conditioned by the physical–mechanical properties of the rocks, the geometric characteristics and materials of the tools, as well as the cutting process parameters (cutting force, feed rate). Previous studies have mainly addressed the global aspect of wear without delving into the microstructural evolution of the contact surfaces during the friction process. In this paper, through controlled tribometric tests, we have investigated in detail the abrasive wear mechanisms of metallic materials in contact with different types of rocks, with an emphasis on the role played by surface roughness and the mineralogical properties of the rocks. Experimentally, we varied the applied forces and the number of friction cycles to simulate different working conditions and evaluate how these parameters influence wear intensity and surface morphology evolution. Microstructural analysis of the samples, combined with roughness measurements, allowed the identification of the predominant degradation mechanisms (abrasion, adhesion, fatigue) and their correlation with the material properties and the friction process parameters. The results have shown a strong correlation between the wear capacity of rocks and their petrographic properties, such as hardness, porosity, and hard mineral content. It was also found that the roughness of the contact surfaces plays an essential role in wear mechanisms, influencing both the initiation and propagation of its effects. Depending on the experimental data, we have developed a classification of rocks based on their abrasive potential and proposed criteria for the optimal adoption of materials and working parameters for the tools of technological equipment depending on the type of rock encountered. The results of this study can contribute to improving the durability of tools, as well as mining equipment, and reducing operating costs. [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]

The aim of this paper is to investigate the effect of TiC addition on the microstructure, microhardness, and wear resistance of the medium-entropy alloy Co37Cr28Ni31Al2Ti2, which is suitable for applications in aerospace, automotive, and energy industries due to its high strength and wear resistance. The samples containing 0, 10, 20, and 40 wt.% of TiC were synthesized. The alloy's microstructure changes significantly with the addition of TiC particles: they are uniformly dispersed in the FCC matrix, effectively increasing the Vickers hardness from 439 HV for the base alloy to 615 HV for the 40% TiC alloy. The four alloys were subjected to reciprocating dry sliding friction tests at loads of 2 N, 5 N, and 10 N. The wear volumes of the base alloy at these loads were 2.7 × 107, 4.6 × 107, and 1.1 × 108 μm3, respectively. The experimental results indicate that adding TiC greatly improves the wear resistance of the alloy by increasing the hardness and forming an oxide protective film. This study highlights the potential for developing alloys with excellent tribological properties for demanding application scenarios. [ABSTRACT FROM AUTHOR]

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]

Aluminum alloys are widely used in industry due to their light weight. These alloys are generally exposed to abrasive wear, which diminishes their effective lifespan. The wear resistance of these alloys is enhanced by adding various reinforcements, however, this enhancement comes at the cost of reduced fracture toughness. This paradox of increased wear resistance versus decreased fracture toughness in aluminum alloys can be resolved by using functionally graded materials (FGMs). This study focuses on the abrasive wear behavior of functional graded aluminum matrix composites reinforced with Al3Ti particles. The wear properties of the composites were investigated by considering the characteristics of the composite such as matrix type and various composite zones, as well as the wear parameters such as abrasive particle diameter, load, sliding speed and distance. Taguchi method was used in the abrasive wear tests in order to get more reliable results in a timeefficient manner. Experiment recipes were created based on the L27(36) orthogonal series. As a result of the study, it is observed that the wear resistance of the composites increases with an increase in Al3Ti reinforcement content and hardness of the matrix. In addition, the size of abrasive particles and the applied load are significant factors affecting abrasive wear. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic 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.)

Ultrahigh-molecular-weight-polyethylene (UHMWPE) is extensively applied to make bone and cartilage implants in the field of biomaterial application. UHMWPE matched with a metal or ceramic component withstands the long-term effect of cyclic stress, which induces UHMWPE serious wear, and affects the service life of the artificial joint. This investigation focuses on the influence of pores on the mechanical and tribological property of UHMWPE. The porosity, crystallinity, yield strength, tensile strength, hardness, compression yield strength, creep resistance, wettability, friction performance, and wear mechanism of solid and porous UHMWPE were evaluated and compared. The research results indicated that the pore had a remarkable influence on the mechanical, friction, and wear property of UHMWPE. The porosity of porous UHMWPE was 29.7% when 50 wt. % sodium chloride (NaCl) was added and the pore size was about 200 μm. The crystallinity, hardness, creep resistance, strength, and elongation decreased after NaCl was added and dissolved. However, the yield strength in the tensile and compression test was closer to that of the natural cartilage. The friction coefficient and wear loss of porous UHMWPE were higher than that of solid UHMWPE in dry conditions, but these values of porous UHMWPE were lower than that of solid UHMWPE in the calf serum lubrication condition. The main wear mechanism of porous and solid UHMWPE was abrasive. The lubricity of calf serum reduced wear surface scratches and furrows, especially for porous UHMWPE. [ABSTRACT FROM AUTHOR]

This study investigates the optimization of boron coating parameters for medium-carbon steels, specifically AISI 1137, and their subsequent effects on mechanical properties, which are crucial for industrial applications. Despite extensive research on boronizing processes, an understanding of the optimal conditions that enhance wear resistance and hardness while maintaining structural integrity is still lacking. To address this gap, we systematically examined the impact of boronizing temperatures (850 °C and 950 °C) and durations (2, 4, and 8 h) on the structural and mechanical properties of AISI 1137 steel. Our findings indicate the need for improved surface properties in medium-carbon steels used in demanding environments, such as automotive and machinery components. The boronizing process was carried out using Ekabor 1 powder, with characterization performed through optical microscopy, pin-on-disk wear tests, and Vickers hardness analysis. Results showed that the thickness of the boronized layer ranged from 50.6 μm to 64.8 μm, with wear resistance increasing by 1.8 to 3.9 times at 950 °C compared to at 850 °C. The measured hardness of the boronized surface layers varied between 1963.7 HV and 219.3 HV, decreasing from the boronized layer toward the base material. The optimal parameters for wear resistance and hardness were found to be a temperature of 950 °C and a duration of 8 h, facilitating the formation of FeB and Fe2B phases, which significantly enhanced the steel's mechanical properties. This research provides valuable insights into the boronizing process and establishes a foundation for the optimizing of surface treatments to extend the lifespan and performance of medium-carbon steels in industrial use. [ABSTRACT FROM AUTHOR]

Copyright of Dokuz Eylul University Muhendislik Faculty of Engineering Journal of Science & Engineering / Dokuz Eylül Üniversitesi Mühendislik Fakültesi Fen ve Mühendislik Dergisi is the property of Dokuz Eylul Universitesi Muhendislik Fakultesi Fen ve Muhendislik Dergisi 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.)

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]