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Abrasive machining processes have long been integral to various manufacturing industries, enabling precise material removal and surface finishing. In recent years, the integration of non-Newtonian fluids has emerged as a promising strategy to enhance the performance and efficiency of these processes. This review paper provides a comprehensive overview of the current state of research on abrasive machining processes, including abrasive lapping, abrasive polishing, and chemical mechanical polishing, and then analyzes in detail the abrasive machining processes enhanced with non-Newtonian fluids. It explores the fundamental principles underlying the rheological behavior of non-Newtonian fluids and their application in abrasive machining, with a focus on shear-thickening fluids. The paper will begin by introducing the abrasive machining processes, including abrasive lapping, abrasive polishing, and chemical mechanical polishing. Then, the current research status of non-Newtonian fluids will be comprehensively analyzed, and we will explore the enhancement of abrasive machining processes with non-Newtonian fluids. Finally, the paper will conclude with a discussion of the future directions and challenges in the field of abrasive machining enhanced with non-Newtonian fluids. Overall, this review aims to provide valuable insights into the potential benefits, limitations, and opportunities associated with the use of non-Newtonian fluids in abrasive machining, paving the way for further research and innovation in this promising area of manufacturing technology. [ABSTRACT FROM AUTHOR]

Purpose: Three-dimensional (3D) printed parts usually have poor surface quality due to layer manufacturing's "stair casing/stair-stepping". So post-processing is typically needed to enhance its capabilities to be used in closed tolerance applications. This study aims to examine abrasive flow finishing for 3D printed polylactic acid (PLA) parts. Design/methodology/approach: A new eco-friendly abrasive flow machining media (EFAFM) was developed, using paper pulp as a base material, waste vegetable oil as a liquid synthesizer and natural additives such as glycine to finish 3D printed parts. Characterization of the media was conducted through thermogravimetric analysis and Fourier transform infrared spectroscopy. PLA crescent prism parts were produced via fused deposition modelling (FDM) and finished using AFM, with experiments designed using central composite design (CCD). The impact of process parameters, including media viscosity, extrusion pressure, layer thickness and finishing time, on percentage improvement in surface roughness (%ΔRa) and material removal rate were analysed. Artificial neural network (ANN) and improved grey wolf optimizer (IGWO) were used for data modelling and optimization, respectively. Findings: The abrasive media developed was effective for finishing FDM printed parts using AFM, with SEM images and 3D surface profile showing a significant improvement in surface topography. Optimal solutions were obtained using the ANN-IGWO approach. EFAFM was found to be a promising method for improving finishing quality on FDM 3D printed parts. Research limitations/implications: The present study is focused on finishing FDM printed crescent prism parts using AFM. Future research may be done on more complex shapes and could explore the impact of different materials, such as thermoplastics and composites for different applications. Also, implication of other techniques, such as chemical vapour smoothing, mechanical polishing may be explored. Practical implications: In the biomedical field, the use of 3D printing has revolutionized the way in which medical devices, implants and prosthetics are designed and manufactured. The biodegradable and biocompatible properties of PLA make it an ideal material for use in biomedical applications, such as the fabrication of surgical guides, dental models and tissue engineering scaffolds. The ability to finish PLA 3D printed parts using AFM can improve their biocompatibility, making them more suitable for use in the human body. The improved surface quality of 3D printed parts can also facilitate their sterilization, which is critical in the biomedical field. Social implications: The use of eco-friendly abrasive flow finishing for 3D printed parts can have a positive impact on the environment by reducing waste and promoting sustainable manufacturing practices. Additionally, it can improve the quality and functionality of 3D printed products, leading to better performance and longer lifespans. This can have broader economic and societal benefits. Originality/value: This AFM media constituents are paper pulp, waste vegetable oil, silicon carbide as abrasive and the mixture of "Aloe Barbadensis Mill" – "Cyamopsis Tetragonoloba" powder and glycine. This media was then used to finish 3D printed PLA crescent prism parts. The study also used an IGWO to optimize experimental data that had been modelled using an ANN. [ABSTRACT FROM AUTHOR]

During the curved surface lapping processing by robot, the surface quality of the processed workpieces cannot be fully guaranteed because of the uncontrollability of lapping contact force. Therefore, the accurate control of the contact force between the tool and the workpiece is important to improve the processing quality. This paper proposes an impedance control strategy based on an optimized environmental model to address the serious constraints brought by the uncertainty of the environmental model in impedance control on the compensation accuracy of contact force and constructed a contact environmental model of elastic abrasives based on neural network algorithm, which improved the compensation accuracy of contact force through iterative iteration and prediction between the environmental model and the impedance model. Constant force control is achieved through accuracy compensation, which ultimately leads to an improvement in the surface quality of the workpiece. Through comparison experiments, it is found that compared with the unoptimized method, the force control tracking error is reduced by 60.9%, the contact force variance is reduced by 25.7%, the contact force error during curved surface force control lapping process is reduced by 58.3% and the contact force variance is reduced by 52.5%, and the workpiece roughness Ra value is reduced by 37.2%. Therefore, the robotic constant force control system based on optimized environmental model can achieve a better force control effect, which can realize accurate and stable control of contact force during curved surface lapping process by robot, and has certain potential for engineering application. [ABSTRACT FROM AUTHOR]

As an important indicator of the surface quality of workpieces, surface roughness has a great impact on production costs and the quality performance of the finished components. Effective surface roughness prediction can not only increase productivity but also reduce costs. However, the current methods for surface roughness prediction have some limitations. On the one hand, the prediction accuracy of classical experimental and statistical-based surface roughness prediction methods is low. On the other hand, the results of deep learning-based surface roughness prediction methods are uninterpretable due to their black-box learning mechanism. Therefore, this paper presents an ensemble learning with a differential evolution algorithm, applies it to the prediction of surface roughness of abrasive water jet polishing (AWJP), and conducts an interpretability analysis to identify key factors contributing to the prediction accuracy of surface roughness. First, we proposed automatically constructing features by an Evolution Forest algorithm to train the base regression models. The differential evolution algorithm with a simplified encoding mechanism was then used to search for the best weighted-ensemble to integrate the base regression models for obtaining highly accurate prediction results. Extensive experiments have been conducted on AWJP to validate the effectiveness of our proposed methods. The results show that the prediction accuracy of our proposed method is higher than the existing machine learning algorithms. In addition, this is the first of its time for the contributions of machining parameters (i.e., features) on surface roughness prediction by using interpretable analysis methods. The analysis results can provide a reference basis for subsequent experiments and studies. [ABSTRACT FROM AUTHOR]

Double-sided planetary grinding (DSPG) with a fixed abrasive is widely used in sapphire substrate processing. Compared with conventional free abrasive grinding, it has the advantages of high precision, high efficiency, and environmental protection. In this study, we propose a material removal rate (MRR) model specific to the fixed-abrasive DSPG process for sapphire substrates, grounded in the trajectory length of abrasive particles. In this paper, the material removal rate model is obtained after focusing on the theoretical analysis of the effective number of abrasive grains, the indentation depth of a single abrasive grain, the length of the abrasive grain trajectory, and the groove repetition rate. To validate this model, experiments were conducted on sapphire substrates using a DSPG machine. Theoretical predictions of the material removal rate were then juxtaposed with experimental outcomes across varying grinding pressures and rotational speeds. The trends between theoretical and experimental values showed remarkable consistency, with deviations ranging between 0.2% and 39.2%, thereby substantiating the model's validity. Moreover, leveraging the insights from this model, we optimized the disparity in the material removal rate between two surfaces of the substrate, thereby enhancing the uniformity of the machining process across both surfaces. [ABSTRACT FROM AUTHOR]

Super-reduced phases (SRPs), such as silicon carbide (SiC) and metal silicides, have increasingly been reported in various geological environments. However, their origin remains controversial. SRP inclusions (e.g., metal silicides and metallic silicon (Si0)) within SiC are commonly believed to indicate a natural origin. Here, we identified an unusual SRP assemblage (SiC, (Fe,Ni)Si2, and Si0) in situ in an H5-type Jingshan ordinary chondrite. Simultaneously, our analysis showed that the SiC abrasives contain (Fe,Ni)Si2 and Si0 inclusions. Other inclusions in the artificial SiC were similar to those in natural SiC (moissanite) reported in reference data, including diverse metal silicides (e.g., FeSi, FeSi2, Fe3Si7, and Fe5Si3), as well as a light rare earth element-enriched SiO phase and Fe-Mn-Cr alloys. These inclusions were produced by the in situ reduction of silica and the interaction between Si-containing coke and hot metals during the synthesis of the SiC abrasives. The results demonstrate that the SRP assemblage in the Jingshan chondrite originates from abrasive contamination and that the SRP inclusions (with a low content of Ca, Al, Ti, and Zr) cannot be used as a conclusive indicator for natural SiC. Additionally, the morphologies, biaxiality, and polytypes (determined by Raman spectroscopy) of SiC abrasives bear resemblance to those reported for natural SiC, and caution must be exercised when identifying the origin of SRP in samples processed by conventional methods using SiC abrasives. At the end of this paper, we propose more direct and reliable methods for distinguishing between natural and synthetic SiC. [ABSTRACT FROM AUTHOR]

In order to evaluate the abrasive belt grinding performance, this paper proposes to conduct nickel-based superalloy robot abrasive belt grinding experiment based on different types of abrasive belts with multiple grit sizes. First, the single grinding performance evaluation is performed through five performance parameters: material removal rate, surface roughness, tangential force, specific grinding energy, and specific wear height. Then, based on the evaluation results of single grinding performance, a weighted evaluation function is established to comprehensively evaluate the grinding performance. It is found that the structured abrasive belt has relatively better grinding performance. The main factors affecting the abrasive belt grinding performance are identified through the evaluation results, with the effect of grit size being more significant. In addition, this paper analyzes the characteristics of material deformation based on the grinding subsurface microstructure, and discusses the effects of abrasive belts on material deformation. [ABSTRACT FROM AUTHOR]

Abrasive water jet polishing has significant advantages in the manufacturing of complex optical components (such as high-slope optical component cavities) that require high-precision manufacturing. This is due to its processing process, in which the polishing tool does not make direct contact with the surface of the workpiece, and instead maintains a considerable distance. However, the removal functions of most existing abrasive water-jet polishing technologies do not possess strict symmetry, which significantly impacts the ability to correct surface figure errors. Therefore, this study implements rotating abrasive water-jet polishing based on traditional abrasive water jet processing to optimize the removal function, which turns it into a Gaussian form; thus, obtaining a type of removal function more suitable for CCOS polishing. This paper derives an empirical formula between the distance s' from the peak removal point of the removal function to the stagnation point and the nozzle tilt angle α, based on geometric relationships and experimental results, analyzes the relationship between material removal efficiency, nozzle tilt angle, and standoff distance. Finally, this paper verifies through experiments the validity of this empirical formula under different process parameters. Therefore, this study obtains the process conditions that allow rotating abrasive water-jet polishing technology to achieve a stable Gaussian form removal function, and the appropriate process parameters to be selected in conjunction with polishing efficiency; thereby, effectively improving the removal function's corrective ability and manufacturing efficiency. It provides theoretical support for the processing capability and process parameter selection of abrasive water-jet polishing technology, solves the problem of limited shaping capability of existing abrasive water jet tools, and significantly improves the manufacturing capability of high-end optical components. [ABSTRACT FROM AUTHOR]

A novel collision detection algorithm of abrasive belt grinding blade integrated disk (blisk) based on improved octree segmentation is proposed, to improve the accuracy and efficiency of collision detection while ensuring dimensional accuracy and surface quality. The traditional collision detection algorithm model is described in detail, among them, the collision detection model of the abrasive belt is obtained by establishing its Oriented Bounding Box (OBB), and the collision detection model of the blisk is established by the octree segmentation. Then, an improved octree segmentation based on k-means clustering method can be presented by analyzing the important factors that affect the collision detection; on this basis, an algorithm of collision detection for abrasive belt grinding blisk is given. Finally, algorithm verification and experimental verification are carried out based on a blisk with certain type, respectively. Compared with the traditional collision detection algorithm, the results with algorithm verification illustrate that the accuracy and efficiency of algorithm in this paper have promoted by 45% and 18.60%, respectively; and the results with experimental verification demonstrate that the accuracy and efficiency of algorithm in this paper have improved by 45% and 18.44%, respectively. [ABSTRACT FROM AUTHOR]

This paper introduces an Acoustic Emission (AE)-based monitoring method designed for supervising the Abrasive Waterjet Cutting (AWJC) process, with a specific focus on the precision cutting of Carbon Fiber-Reinforced Polymer (CFRP). In industries dealing with complex CFRP components, like the aerospace, automotive, or medical sectors, preventing cutting system malfunctions is very important. This proposed monitoring method addresses issues such as reductions or interruptions in the abrasive flow rate, the clogging of the cutting head with abrasive particles, the wear of cutting system components, and drops in the water pressure. Mathematical regression models were developed to predict the root mean square of the AE signal. The signal characteristics are determined, considering key cutting parameters like the water pressure, abrasive mass flow rate, feed rate, and material thickness. Monitoring is conducted at both the cutting head and on the CFRP workpiece. The efficacy of the proposed monitoring method was validated through experimental tests, confirming its utility in maintaining precision and operational integrity in AWJC processes applied to CFRP materials. Integrating the proposed monitoring technique within the framework of digitalization and Industry 4.0/5.0 establishes the basis for advanced technologies such as Sensor Integration, Data Analytics and AI, Digital Twin Technology, Cloud and Edge Computing, MES and ERP Integration, and Human-Machine Interface. This integration enhances operational efficiency, quality control, and predictive maintenance in the AWJC process. [ABSTRACT FROM AUTHOR]

The generation of abrasive particles is an unavoidable consequence of sliding electrical contact wear in conductive slip rings (SRs). The adhesion of abrasive particles to the insulators may lead to a decrease in flashover voltage, posing a risk to satellite power transmission. In this paper, the effect of abrasive particles on flashover is first studied. Surface abrasive particles can distort the surface electric field of the dielectric, absorb scattered electrons, and then re-emit them, thereby accelerating the development and formation of secondary electron avalanches. Flashover test results indicate that surface abrasive particles lead to a significant reduction in flashover voltage. To mitigate the impact of particle adhesion on flashover, a method of constructing particle traps on the surface of insulators is proposed. The location and structural parameters of the particle trap are further optimized and determined. The flashover test results using planar dielectric samples and SR insulator samples both demonstrate that the optimized particle trap can significantly improve the flashover voltage. The dielectric maintains high electrical strength even when particles are trapped in particle traps. The physical details of the impact of particles on flashover and the effect of particle traps are analyzed utilizing an electron movement simulation, corroborating the experiment from a microscopic aspect. [ABSTRACT FROM AUTHOR]

A supercritical suspended abrasive water jet with dual inputs of pressure and heat is proposed to improve the cutting performance of the conventional suspended abrasive water jet in deep-sea environments. The paper studies the flow and kinetic characteristics of the supercritical suspended abrasive water jet. The CFD simulation method is proposed to investigate these characteristics by integrating a programmed database of supercritical water material properties with Ansys Fluent. The simulation and comparison show that abrasive particle density, abrasive particle size, inlet pressure, and water temperature affect the acceleration process of the abrasive particles. At the nozzle outlet, the velocity of the abrasive particles reaches over 95% of the supercritical water velocity. With the proposed supercritical abrasive water jet, the jet velocity is increased by 192.2% to 402.40 m/s compared to the conventional suspended abrasive water jet, reducing the amount of water used by 67.7% at a specified temperature of 773.15 K. Correspondingly, the medium kinetic energy is increased by 177.7% and the medium kinetic energy ratio is 2.78. The particle kinetic energy is increased by 723.2% and the particle kinetic energy ratio is 8.23. [ABSTRACT FROM AUTHOR]

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Rail grinding with abrasive belt is increasingly applied in daily rail maintenance due to its high efficiency and high quality. The contact between rail and abrasive belt largely determines grinding efficiency and grinding quality, but the influences of grinding process and contact wheel’s parameters on the contact behaviour are obscure. To explore the influences, a finite element model of the wheelrail contact was established. The simulation results showed that the grinding angle significantly affected the shape of contact spot. The contact spot gradually became narrower as the grinding angle increased. Similarly, the reduction of the contact wheel radius significantly increased the contact stress. But when the ratio of the thickness of rubber layer to wheel radius increased above 60 %, it had little effect on the size of contact spot and maximum contact stress. This study provides the basis for the selection of grinding process and contact wheel’s parameters. In the actual grinding process, grinding process and contact wheel should be selected according to grinding requirements. (Received in April 2022, accepted in June 2022. This paper was with the authors 2 weeks for 1 revision.) [ABSTRACT FROM AUTHOR]

This paper presents an experimental study of abrasive waterjet turning of an extrusion aluminum alloy (AlMg0,7Si). The aim of the paper is to determine differences of two methods from the point of view of machined surface quality and the depth of penetration, i.e., the diameter of the parts after the turning process. During the experiments, the traverse speed of the cutting head and the rotation of the turned parts were changed, other parameters, like pressure of the water, abrasive mass flow rate were kept constant. Diameter and some surface roughness parameters of the test parts were measured after the machining. On the base of experimental results, advantages, and disadvantages of two methods are explained in the paper. [ABSTRACT FROM AUTHOR]

The abrasive wear response of Al-7.5Si–SiC composite produced by stir casting technique was examined and compared to Al-7.5Si alloy (matrix alloy) and Al-17.5Si (low-cost hypereutectic) alloy in as-cast and after heat treatment. The microstructure of the hypereutectic alloy shows the α-Al, α-Si, and Al-Si eutectic phases, and the microstructure of the composite shows the homogeneous dispersion of SiCp in the matrix and excellent bonding of the Al-SiC interface. The wear examinations were performed on pin-on-disc apparatus at 38–80 µm abrasive (grit) sizes, 5–20 N applied loads, 100–400 m sliding (abrading) distances, and 1 m/s constant sliding speed. At 80 µm size of abrasive and 20 N of the applied load, the decrement in wear rate of LM30 alloy and LM25-SiCp composite was 31.82% and 95.37%, respectively, in case of the as-cast condition. However, for heat-treated conditions, the decrement in wear rate of hypereutectic alloy and composite was 32.63% and 96.61%, respectively. The wear rate of specimens was increased with abrasive size and applied load. The wear resistance of the hypereutectic alloy was superior to the matrix alloy but inferior to the composite irrespective of the abrasive size and applied load. The wear surface of the specimens, abrasive papers, and wear debris were analysed by the field-emission scanning electron microscope (FESEM) for the wear mechanism. [ABSTRACT FROM AUTHOR]

Abrasive belt condition (BC) monitoring is significant for achieving profile finishing precision and quality in grinding of difficult-to-machine materials like Inconel 718. While indirect signal-based BC monitoring methods are ineffective when varying grinding parameters, existing image-based direct monitoring methods currently suffer from a lack of: (i) a unified and quantitative definition of the belt condition; (ii) in situ tool-surface image capture and relevant feature extraction; and (iii) continuous monitoring of the entire belt conditions. This paper proposes a partitioned BC monitoring method that is adaptable to ever-changing grinding conditions. Based on the belt surface analysis, a unified BC coefficient is quantitatively defined by using two critical BC-dependent features, the average area and number of worn flats of abrasive grains per unit area. The belt surface image is in-situ captured from moving belts and is preprocessed to eliminate image defects in a unified form, then the entire belt is partitioned, and finally the image features are extracted by Gabor filter and K-means clustering. The proposed robust method which has a maximum relative repeatability error of 9.33%, and less computation was validated by the experimental results. This study provides an adaptable and efficient way for continuously monitoring the conditions of the entire belt and the grinding area. [ABSTRACT FROM AUTHOR]

The demand for high-precision and high-efficient machining of high-performance materials and components has increased in various industries such as optical, automotive, communication, life sciences, and medical sciences. Certain difficult-to-machine materials can be reliably machined using deterministic precision cutting processes. However, hard and brittle materials such as ceramics, carbides, hardened steel molds, glassy materials, or semiconductor materials, require precision abrasive technologies with super abrasives like diamond, cBN, or new tool materials for machining. However, machining high-precision components and their molds/dies using abrasive processes is considerably more difficult due to their complex and non-deterministic nature and textured surfaces. Furthermore, high-energy processes such as laser technology can assist abrasive technologies in ensuring higher precision and efficiency. Precision grinding and polishing processes are primarily used to generate high-quality and functional components, typically made of difficult-to-machine materials. Thus, the surface quality achievable by precision grinding and polishing processes becomes more important for reducing machining time and costs. This special issue features 10 papers on the most recent advances in precision abrasive technologies. These papers cover the following topics: - Ultrasonic grinding of micro holes using cemented WC tools - Drilling holes in CFRP aircraft using cBN electroplated ball end mill - In situ evaluation of drill wear using tool images - Grinding belt based on modified information entropy - Radial directional vibration-assisted grinding of Al2O3 ceramics - Chatter vibration suppression using fixed superabrasive polishing stone - Free abrasive finishing of internal channels with different cross-sectional geometries - High-quality machining of cemented carbide using PCD ball end mills - Fixed-abrasive machining with magnetic brush for Ti-6Al-4V ELI alloy - High-efficient polishing of polymer surfaces using catalyst-referred etching This issue will provide an understanding of the recent developments in abrasive technologies, leading to further research. We deeply appreciate the careful work of all the authors, and we thank the reviewers for their incisive efforts. [ABSTRACT FROM AUTHOR]

Abrasive water jet peening, which integrates the characteristics of water jet peening and shot peening, is a potential process for surface strengthening of metal materials. In this paper, the peening process of 316L stainless steel by abrasive water jet was studied in this paper. The effects of standoff distance and traverse speed on peening quality and efficiency were analyzed. On this basis, the selection strategy of these two parameters was clarified. The results show that the core zone, transition zone, and minute effect zone were formed at the impact part due to the change of the energy of abrasive water jet. Among them, the peening quality of the core zone is the best. With the increase of standoff distance and traverse speed, the peening quality of the core zone decreased, but the efficiency was greatly improved. In practical application, the standoff distance and traverse speed can be set according to the actual needs. From the perspective of efficiency, on the basis of meeting the needs of peening quality, the standoff distance and traverse speed should be set to a high level. [ABSTRACT FROM AUTHOR]

Polishing force is a critical process parameter in the polishing process, and its magnitude has a great impact on surface integrity, polishing temperature, and polishing efficiency. At present, there is a lack of research on the polishing force of the abrasive cloth flap wheel (ACFW). In order to more accurately predict the value of polishing force for the ACFW, this paper proposes a modeling method of polishing force for the ACFW based on elastic–plastic contact theory. Firstly, this paper makes the statistical analysis of the protrusion height of abrasive grains (PHAGS) and proposes a calculation method of the contact number of active abrasive grains (CNABGS) for the ACFW based on the probability distribution theory and the flexible polishing principle of the ACFW. Secondly, according to the elastic–plastic contact theory, the interaction process between single abrasive grains and the workpiece is analyzed, and the mean polishing force model of single abrasive grains is developed. Finally, the polishing force model of the ACFW was obtained by combining the calculation method of the CNABGS and the mean polishing force model of the single abrasive grain, and the model was verified by polishing experiments. The experimental results showed that the relative mean percentage error between the measured and predicted values of polishing force was 13.31%, and the maximum value of the absolute error was 0.59, which proved that the polishing force model of the ACFW is reliable and accurate. [ABSTRACT FROM AUTHOR]

Abrasive water jet machining (AWJM) is an unconventional cutting method used in different industrial applications. The motive of this paper is to investigate the effect of traverse speed on surface roughness for a particular workpiece thickness. Three different plates of AISI 1030 steel as work-piece with thicknesses 4 mm, 6 mm and 8 mm are used to evaluate surface quality of cutting. Three response models for respective thicknesses are generated and checked on the basis of their prediction ability. It showed 8.71%, 8.11% and 7.83% error for surface roughness for three different thicknesses, respectively. Post validation, desired surface roughness values are placed in the response models for prediction of respective traverse speeds for three different thicknesses and represented in a graphical manner. This paper will help the AWJ machining operator to find out the precise cutting speed for achieving desired surface roughness. [ABSTRACT FROM AUTHOR]

In this paper, AlSi10Mg alloy powder is selected as the forming powder of Selective laser melting technology, and the AlSi10Mg alloy SLM curved surface sample is constructed by setting the internal and external layering parameters. In view of the relatively rough surface roughness of SLM technology molded parts, this paper selects the magnetic finishing technology with higher flexibility characteristics to perform surface finishing and finishing on the formed curved surface samples. Explore the feasibility of magnetic finishing technology on the finishing of SLM shaped curved parts, and test and analyze the surface roughness, surface hardness and hydrophobicity of the finishing permanent magnet tools and the curved surface samples before and after finishing. Finally, it was found that the use of a 75° trapezoidal slotted permanent magnet finishing tool to absorb spherical Al2O3 magnetic abrasives for flexible finishing of AlSi10Mg alloy SLM shaped curved surface samples can achieve better finishing results. In this paper, the orthogonal experiment method is used to optimize the finishing experiment. It is found that the finishing parameters of the spindle speed is 1800 r/min, the feed rate is 5 mm/min, the gap is 2 mm, and the abrasive consumption is 7 g to form the AlSi10Mg alloy SLM. The surface roughness Ra = 0.279 μm can be obtained by magnetic finishing of the curved sample, and the surface morphology of the sample has been greatly improved. At the same time, it is found that the magnetic finishing technology improves the surface roughness of the AlSi10Mg alloy SLM forming surface sample, while it does not change the surface hardness of the sample, but it can significantly improve the hydrophobicity of the sample surface. [ABSTRACT FROM AUTHOR]

This paper discusses the impact of coal abrasive materials of varied petrographic composition and claystones containing admixtures of coal matter on the surface wear of wear-resistant martensitic steels. Wear tests were conducted at a test stand for three petrographic varieties of hard coal: vitrinite, clarinite, and durinite, and five samples of claystone. These tests revealed no significant effect of the type of coal abrasive used on the value of mass loss from the surface of the wear-resistant steel samples. The reason behind the foregoing is the observed tendency of coal abrasives, irrespective of their petrographic variety, to penetrate surface irregularities, especially those attributable to previous surface treatment of the samples and the impact of wear products. The dominant forms of surface damage were surface fatigue chipping and scratches caused by the particles which detached themselves from the surface of the steel samples, as observed for all the analysed coal variants. On the surfaces of the samples seasoned in the presence of claystones, highly varied forms of damage were observed: microcutting, scaly surface cracks, delamination, and deep cracks. In these cases, it was possible that the abrasive grains had been pressed into the steel surface irregularities, but no layered forms of the pressed-in abrasive material were observed to have developed. The paper also presents a model for the formation of coal films and discusses their possible effect on wear minimisation. [ABSTRACT FROM AUTHOR]

Sanding is the most important way of reducing unevenness and preparing the surface for the final treatment. To optimize sanding, it is necessary to quantify the effect of abrasive grit size on surface roughness. The paper deals with the methodology of measuring the surface roughness parameter Ra of beech wood (Fagus sylvatica L.) using a Keyence VHX-7000 digital microscope. After milling, the samples were sanded with abrasives with grit size from P40 to P150, using an eccentric sander. Roughness was evaluated in two directions according to ISO 21920 (2022) standards. Using a two-factor analysis of variance the positive effect of grit size on roughness was proven. It improved on average by 38% in the direction perpendicular to the grain and by 20% parallel to the grain. The theoretical knowledge about equalizing the unevenness of the surface by sanding and reducing the difference between the roughness in two directions is proven in the paper. [ABSTRACT FROM AUTHOR]

Automatic polishing of complex parts with flexible abrasive tools has received extensive attention due to its good compliance. Many parameters control the polishing process, but critical process parameters can significantly affect the polishing effect. As a specific case, the relative feed direction of abrasive cloth flap wheel (ACFW) polishing has not been studied enough. In this paper, two targeted experiments were carried out to reveal the removal characteristics of abrasive grains during polishing with the ACFW and the influence of relative feed direction on surface texture. The surface texture parameters are tested and analyzed, including roughness, waviness, and texture direction. Then the influence mechanism of relative feed direction is analyzed, and how to reasonably select the relative feed direction angle is discussed. The research results show that the polishing area is asymmetric relative to the project axis, and there are craters impacted by abrasive grains at the ACFW contact-in side, while the scratch on the contact-out side gradually becomes shallow to disappear. In single-line polishing, the roughness of longitudinal polishing is the best, and the waviness of oblique polishing is the best. The polished mark is along the feed direction by direct observation, but the texture direction observed by magnification is the cutting direction of abrasive grains. The characteristics of abrasive grain trajectory and contact force distribution can well explain the resulting surface texture difference. [ABSTRACT FROM AUTHOR]

The presented paper is focused on the evaluation of material removal during machining via an abrasive water jet with a controlled depth of cut. In the introductory parts of the work, a theoretical analysis of water jet technology and an analysis of the current state of the problem are presented. The experimental part of the work is devoted to testing the effects of technological parameters on material removal from the point of view of the maximum erosion depth and volume loss of material during machining with a low water pressure of 50 MPa. The tested material was a Ti 6Al 4V titanium alloy. The experiments were carried out by changing the traverse speed of the cutting head, the mass flow of the abrasive and the angle of inclination of the cutting head, according to the DoE 33 experiment plan. The obtained values were evaluated using the method of variance (ANOVA) and regression analysis. Furthermore, the values of the width of the erosion track and the maximum and minimum erosion effects for both tested materials were evaluated. [ABSTRACT FROM AUTHOR]

This paper presents the research results on the influence of vibration abrasive machining parameters on the surface layer integrity of elements made by LPBF technology from Inconel 939. The research was carried out on samples of various sizes on vibrating smoothing machines. The influence of the size of the processed elements, the type of abrasive shapes, the processing time, and the supporting fluid on the surface roughness and microstructure of the processed elements was analyzed. Tests have shown that as a result of using vibration processing, it is possible to reduce the surface roughness five times to the value of Ra = 1.1 µm. A significant influence of the type of abrasive shapes was found. There was no significant effect of the machining fluid on the process. [ABSTRACT FROM AUTHOR]

Multistage hydraulic fracturing has been proven to be an effective stimulation method to extract more oil from the depleted unconsolidated sandstone reservoirs in Bohai Bay, China. The offshore wellbores in this area were completed with a gravel pack screen that is much too difficult to be mechanically isolated in several stages. Hydra-jet fracturing technology has the advantages of multistage fracturing by one trip, waterjet perforation, and hydraulic isolation. The challenges of hydraulic-jet fracturing in offshore unconsolidated sandstone reservoir can be summarized as follows: the long jet distance, high filtration loss, and large pumping rate. This paper proposes full-scale experiments on the waterjet perforation of unconsolidated sandstone, waterjet penetration of screen liners and casing, and pumping pressure prediction. The results verified that multistage hydra-jet fracturing is a robust technology that can create multiple fractures in offshore unconsolidated sandstone. Lab experiments indicate that the abrasive water jet is capable to perforate the screen-casing in less than one minute with an over 10 mm diameter hole. The water jet perforates a deep and slim hole in unconsolidated sandstone by using less than 20 MPa pumping pressure. Recommended perforating parameters: maintain 7% sand concentration and perforate for 3.0 min. Reduce sand ratio to 5%, maintain 3.0 m3/min flow rate, and continue perforating for 7.0 min. The injection drop of the nozzle accounts for more than 62% of the tubing pump pressure. The recommended nozzle combinations for different fracturing flow rates are 8 × ø6 mm or 6 × ø7 mm for 2.5 m3/min and 3.0 m3/min, and 8 × ø7 mm for 3.5 m3/min and 4.0 m3/min. A one-trip-multistage hydra-jet fracturing process is recommended to be used for horizontal wells in offshore unconsolidated sandstone reservoirs. [ABSTRACT FROM AUTHOR]

Magnetic abrasive finishing is a process that uses loose abrasive particles with ferromagnetic particles in the presence of the magnetic field to perform fine surface finishing in the order of nanometers. The paper brings out a novel magnetic abrasive finishing setup that can, in real-time, vary the number of abrasive particles in the finishing zone. The proposed MAF setup uses a disc-shaped magnet and finishing is performed using a ferromagnetic brush and externally supplied suspension of SiC particles and distilled water through the nozzle. In the proposed process, the quantity of abrasive particles in the suspension and the suspension flow rate can be varied during the finishing. The setup was mounted on a lathe machine and the finishing was performed on plane SS304 material (non-magnetic). The experiments were performed to explore the process capabilities on a plane SS304 workpiece material. The process parameters such as the quantity of abrasive particles in the suspension, suspension flow rate, rotational speed of the magnetic disc and working gap are considered. Their influence on the response change in surface roughness is presented. A significant change in surface roughness of 79.41% was observed in the first 5 min of the finishing. The minimum roughness value of 29 nm was achieved from an initial 408 nm using the selected set of parameters on the developed setup. The SEM micrographs were also observed to analyze the surface texture of the finished surface. They revealed a random scratching pattern ensuring a true random behavior of the finishing process. [Display omitted] • The paper brings out a novel magnetic abrasive finishing setup that can address the replenishment as well as the supply rate of abrasive particles in the finishing zone. • The proposed setup eliminates the limit for the concentration of abrasive particles introduced in the finishing zone. • A true random scratching behavior was achieved during the finishing without any additional mechanism. • The minimum R a of 29 nm was achieved from an initial 408 nm using the selected set of process parameters. [ABSTRACT FROM AUTHOR]

Whitening has been known since Biblical times. Nowadays, in the developed world, patients are placing a stronger interest in the aesthetic appearance of their teeth. As a result, public demand for aesthetic dentistry, including tooth whitening, has recently increased. Aesthetics of the teeth is of great importance to many patients. The aim is to summarise and discuss the teeth whitening procedure, tools, materials, and methods, as well as its efficacy and safety. In addition, the paper aims to provide full and comprehensive information for dentists and their patients about the merits and perils of whitening. Methods. Relevant literature from Scopus published in English was selected using the following search criteria "tooth OR teeth AND whitening OR bleaching" by 2022. In total, there were found 3840 papers. Then, we applied the inclusion and exclusion criteria to the selected scientific papers to choose the relevant ones. Results. A comprehensive study of the available information related to means and products for teeth whitening was carried out. Whitening may be accomplished by the physical removal of the stain or a chemical reaction to lighten the tooth colour. The indications for appropriate use of tooth-whitening methods and products depend on the correct diagnosis of the discolouration. When used appropriately, tooth-whitening methods are safe and effective. Conclusions. Tooth whitening is a form of dental treatment and should be completed as part of a comprehensive treatment plan developed by a dentist after an oral examination. [ABSTRACT FROM AUTHOR]

In this paper, a novel polishing method, submerged air jet polishing (SAJP), is proposed. In this method, the nozzle and workpiece are completely immersed in the abrasive fluid. When the compressed air is sprayed from the nozzle in the abrasive fluid at high velocity onto the workpiece surface, the material removal occurs on the workpiece surface due to abrasive contact and cavitation. The main finding of this paper is to establish the microscopic theoretical model of SAJP on the basis of the micro-cutting model of the single abrasive particle. The erosion removal mechanism of SAJP processing titanium alloy was studied by simulation combined with experiments, and the material removal mechanism under different process parameters was explored from the perspective of microscopic evolution. [ABSTRACT FROM AUTHOR]

Kinematic principle in lapping process is an essential theoretical foundation to achieve high lapping accuracy. The motion path of abrasive grains determines the machined area on workpiece, thereby affecting the surface accuracy. To improve lapping uniformity, this paper established a kinematic model of swing fixed-abrasive lapping (SFAL) and investigated the effect of kinematic parameters (rotational speed ratio, swing ratio, swing angle) on lapping uniformity. Non-uniformity coefficient (NUC) was adopted to evaluate the lapping uniformity, and the impact mechanism of kinematic parameters on the trajectory of abrasive grains were revealed by Taguchi experiments and numerical simulation. Furthermore, response surface experiments were employed to optimize the parameter combination, and a prediction model for NUC was developed. This work provides theoretical guidance for the selection of kinematic parameters in SFAL process, and has reference significance for improving the lapping accuracy. [ABSTRACT FROM AUTHOR]

The preparation of cubic boron nitride (CBN) grinding tools using laser cladding has the advantages of strong bonding, short time consumption and customizable abrasive arrangement. In this paper, a two-step laser cladding method was used to prepare CBN abrasive blocks with the aim of reducing laser damage to CBN grits during the laser cladding process. The cross-sectional morphology of CBN abrasive blocks under different laser power conditions was characterized, and the relationship among laser power, preparation method, and forming quality of Cu–Sn–Ti/CBN cladding layer was investigated. Then, the microstructure at the Cu–Sn–Ti/CBN interface under different laser power conditions was characterized, and the main phase compositions at the Cu–Sn–Ti/CBN interface were analyzed. Finally, the grinding tests were carried out on CBN abrasive blocks. The results show that as the laser power increases from 250 W to 400 W, the fracture ratio of CBN grits increases dramatically from 4.3 % to 17.3 %. TiN, TiB 2 , and TiB compounds are all detected at the Cu–Sn–Ti/CBN interface under different laser power conditions. The mass loss of the TC4 wheel caused by the CBN abrasive block initially increases and then decreases as the laser power increases from 250 W to 400 W. The CBN abrasive block has the optimum material removal performance at the laser power of 300 W using two-step laser cladding. The results provide a theoretical basis for the preparation of high-performance CBN grinding tools using laser cladding. [ABSTRACT FROM AUTHOR]

Electroplated diamond wire saw is the main tool for slicing semiconductor materials such as silicon. The quality and efficiency of slicing would be directly affected by the manufacturing quality of the electroplated diamond wire saw. The abrasive protrusion height of the electroplated diamond wire saw is one of the important indexes to evaluate its manufacturing quality. However, only the offline method can be used to detect the protrusion height of the abrasives, which makes it impossible to realize the online control and optimization of the manufacturing process parameters. If the offline detection results are not qualified, the electroplated diamond wire saw with a length of tens of kilometers would be scrapped, which is easy to cause a waste of resources. The above problems could be solved by adding an online detection and feedback adjustment module in the electroplated diamond wire saw manufacturing processes. To this end, the influence of abrasive distribution position on its protrusion height imaging distortion is analyzed. A distortion correction criterion for the abrasive protrusion height is established. Connected domain labeling and Hough transform are used to extract information from electroplated diamond wire saw images. A method based on machine vision is proposed, which can realize the online detection of the protrusion height of abrasives on the surface of the electroplated diamond wire saw. Experiment results show that the detection accuracy of this method is better than that of the offline method. Based on the hardware conditions in this paper, the average sampling interval of this method is 0.15 s, which could meet the online detection requirements for the abrasive protrusion height of the electroplated diamond wire saw. [ABSTRACT FROM AUTHOR]

Ceramic cubic boron nitride (CBN) wheel is widely used in grinding field for its superior grinding performance. The random grain orientation of CBN grinding wheel with ceramic bond affects its grinding performance to a certain extent. In this paper, magnetically controlled ceramic CBN grinding wheel was prepared by magnetic field and sintering process. In order to improve the magnetic conductivity of the abrasive grains, nickel-plated CBN was used to replace the abrasive particles. It was found that the direction of the abrasive particles could be effectively controlled by adjusting the strength and properties of the magnetic field, so that the abrasive particles presented a chain distribution under the magnetic field. The experimental results showed that the nickel-plated CBN abrasive grains have good orientation and chain distribution in the bond power by using alternating magnetic field. Finally, experiments were carried out to study the grinding of GH4169 with magnetically controlled ceramic CBN grinding wheel, and the experimental results were compared with common ceramic CBN grinding wheel. It was confirmed that the grinding temperature and grinding force of GH4169 with magnetically controlled ceramic CBN grinding wheel were slightly lower than that of common grinding wheel, and the grinding surface quality is better than that of ordinary grinding wheel. In this paper, the method of preparing ceramic CBN grinding wheel with controllable grain orientation was established, and the system of evaluating the grinding wheel performance was constructed. It enriched the preparation process of ceramic bond CBN grinding wheel, and would have important significance for further expanding the application of ceramic CBN grinding wheel. [ABSTRACT FROM AUTHOR]

With the advent of the 5G information age, the production and processing of computer chips have attracted people's attention. In order to adapt to the rapid development in the field of chip manufacturing, higher requirements are placed on chemical mechanical planarization (CMP). Due to the porous structure of the polishing pad surface, the polishing pad is prone to clogging and its performance gradually decreases during the polishing process. Therefore, the use of diamond disc conditioner to dress the polishing pad in the CMP process is an indispensable part. In this paper, a new method of measuring the conditioner disc is proposed, the wax is melted and covered on the disc, and after a period of time, it solidifies on the surface of the dressing disc to obtain the protrusion height of the grains; this method has more advantages than measuring with an optical microscope because of the error caused by the diffuse reflection of the microscope. For diamond conditioners used in the experiments, the motion trajectory of abrasive grains is simulated, which is the basis on choosing the experimental method, and the material removal rate model of the polishing pad is established. In addition, after polishing the silicon wafer with a polishing pad for 2 h, the diamond conditioners with orderly distributed abrasive grains are used to dress the pad, the discs can remove the blocking material on the surface of the polishing pad after dressing 30 min, and the dressing effect and efficiency of the diamond disc with grain size of 100 μm are more obvious. The surface roughness and the liquid contact angle of the polishing pad before and after dressing are measured; after a period of conditioning, they can be restored to a state similar to that of the new polishing pad. General scheme of the research [ABSTRACT FROM AUTHOR]

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Chromium and silicon are often introduced to increase the performance of TiAlN hard coatings in dry tribological contacts. The addition of Cr and Si during a high-power impulse magnetron sputtering (HiPIMS) deposition process leads to high-quality TiAlCrSiN films. In this paper, the analysis of friction and wear of these films is conducted by oscillation tribometry under dry conditions with a subsequent mapping of the surface topography. Both abrasion- and adhesion-dominated conditions are realized using different steel counter bodies. Oscillation-frequency-dependent experiments show a significant impact of the compositional variation on friction and wear. It is shown that the TiAlCrSiN coating investigated has a higher coefficient of friction and a lower wear resistance compared to counterparts made of 100Cr6. The friction coefficient could be reduced by using a V2A counterpart. The results can be understood in terms of a reduced adhesion of both oxidic and metallic wear debris at the TiAlCrSiN surface. The study provides valuable progress towards the development of advanced cutting tools, e.g., for stainless steel. [ABSTRACT FROM AUTHOR]

Abrasive water jet machining (AWJM) is the modern machining method used in various industrial applications. In this paper, an attempt has been made to determine optimum AWJM parameters using artificial neural network (ANN). Flow rate of abrasive, stand-off distance and traverse speed are used as input parameters for machining of AISI 1018 steel. Experimental data are used for training and testing of ANN. A feed forward ANN is established using the experimental data obtained during the AWJ machining of steel. Surface roughness (Ra) and kerf taper angle (ϴ) are estimated, on the basis of ANN performance and regression analysis. The regression plots of both responses show more than 97% of agreement among the estimated values and experimental data. Later on, novel approach of model optimisation is executed using univariate analysis on inputs to ANN to get the optimal AWJM process parameters. Optimal response solution is obtained as surface roughness (Ra) = 2.46 μm and taper angle (ϴ) = 1.25° at flow rate (Af) = 450 g/min; stand-off distance (Sd) = 3 mm and traverse speed (Tv) = 85 mm/min. The study shows that the ANN is proficient tool for deciding the optimum AWJ machining parameters. [ABSTRACT FROM AUTHOR]

Laser processing has its advantages of high energy density, good controllability, and high flexibility; it has shown its importance in advancing modern manufacturing. Laser processing is used in this paper to fabricate an end grinding wheel with orderly arranged abrasive particles, and the performance of the fabricated grinding wheel is compared with that of a conventional grinding wheel. Our experiment and comparative studies have drawn the conclusions of (1) active laser brazing has been successfully used to arrange diamond particles in Archimedes' spirals; (2) the resulted grinding wheel has shown the enhanced effectiveness in comparison with the conventional grinding wheel in terms of reduced grinding force; when the spiral change rate i is set 0.25, the tangential grinding force has been reduced by up to 60%; (3) for a grinding wheel with specific spiral change rate, ground debris are discharged from the grinding zone in a certain direction, and the grinding temperature can be reduced; (4) in high-speed grinding, the surface quality by the grinding wheel with orderly arranged abrasive particles is better than that of conventional grinding wheel; under the tested grinding conditions, the roughness of the ground surface has been reduced up to 47% of that by conventional grinding wheels; (5) the grinding wheel with orderly arranged abrasive particles has shown the better wear resistance that conventional grinding wheels; abrasive particles of all four conventional grinding wheels are damaged to certain extent but orderly arranged abrasive particles on the fabricated wheel maintain mostly their protruded heights. [ABSTRACT FROM AUTHOR]

This paper presents a solution aimed at enhancing the accuracy of abrasive waterjet cutting (AWJC) for the processing of carbon-fiber-reinforced polymers (CFRP). Processing CFRP with high accuracy and good surface quality in a short processing time is a difficult task. One crucial problem is the occurrence of shape errors, overcuts, at the cut-in and cut-out point during the cutting process. Shape errors have the potential to create mechanical stress concentrators, which can result in structural failures and compromise the integrity and reliability of components. The primary objective of this study was to gain a comprehensive understanding of the formation mechanism underlying the shape error. The observed shape error is closely associated with both the lead-in/lead-out strategies employed and the process parameters selected. The experimental investigation focused on two commonly used strategies for CFRP cutting: lead-in/lead-out in arc and lead-in/lead-out in line. In order to minimize shape errors, this study proposed a correction method that offers a set of recommendations for selecting the appropriate lead-in/out strategy and a suitable combination of process parameters. Additionally, a mathematical model has been developed to determine the depth of the shape error. The conclusions drawn from this study have been successfully validated through industrial applications. [ABSTRACT FROM AUTHOR]

The mechanical, friction and wear properties of different modified polyoxymethylene (POM) are presented in the paper under free abrasive grinding condition. The shore hardness and elastic modulus of the POM matrix increased with carbon fiber (CF) filling, its shore hardness and elastic modulus were 85 HD and 5000 MPa, respectively. The hardness and elastic modulus of the POM matrix decreased with polytetrafluoroethylene (PTFE) and graphite (C) filling. The average coefficient of friction of POM was 0.254. When PTFE, CF, and graphite were added, the coefficient of friction of the POM would be reduced under free abrasive condition. The coefficient of friction of POM filled with PTFE or graphite was about 0.15, the coefficient of friction of POM filled with CF was about 0.18. It could be seen from the orthogonal test analysis that the wear resistance of four types of materials was CF‐POM > POM > PTFE‐POM > C‐POM. When the test duration was 1.5 h, the wear amount of C‐POM was between 3 and 9 mg, the wear amount of CF‐POM was less than 1.23 mg. The speed and load were the main factors affecting the wear amount of these materials, followed by the abrasive particle diameter, and the abrasive mass fraction had the least effect on them. [ABSTRACT FROM AUTHOR]

As a material with both glass and ceramic properties, glass-ceramics have been widely used because of its low expansion coefficient, stable physical and chemical properties, and good mechanical properties. In order to obtain the super-smooth surface of glass-ceramics, the bonnet polishing method was used in this paper. Firstly, the removal mechanism of glass-ceramics was analyzed, and the influence of particle size on the removal mode was obtained by establishing the indentation depth model of free abrasive particles. Secondly, the best polishing slurry formulation was obtained by investigating the dispersion of abrasive particles in polishing slurry with different kinds and contents of dispersants. Then, through the comparative experiment of glass-ceramics polishing, it was proved that the dispersion effect of abrasive particles in polishing slurry has a significant impact on the polishing quality. Finally, through orthogonal experiments, the optimal processing parameters were selected, and only the alumina abrasive particles with an average size of 2.5 μm were used to obtain a super-smooth surface with a surface roughness Ra of 3.16 nm. [ABSTRACT FROM AUTHOR]

Double-sided lapping process with fixed abrasive shows a strong capability of achieving high efficiency and high surface quality due to its controllable movement of the abrasive and determined material removal modes, and it can be as an alternative technology for fabricating ultra-precision optical components. However, the formation and evolution of the surface topography and roughness (Ra) were rarely clarified in the previous research due to the complicity of the double-sided lapping process. This paper established a new mathematical analytical model to provide a better scientific understanding of the formation and evolution of the surface topography and roughness, in which the spatial location and protrusion height of abrasive particles, each abrasive-material interaction, kinematics trajectory of abrasive particles, and force balance on the workpiece were considered. A series of lapping experiments on the Y3Al5O12 (YAG) wafer were conducted to verify the feasibility of the proposed model and analyze the influence of processing parameters on surface topography and roughness evolution. The results indicated that the proposed analytical model can be effectively used to predict surface topography and optimize the process parameters of double-sided planetary lapping for better surface roughness. The variation of processing time and rotational speed of the lapping plate (pad) possesses a significant influence on surface topography and Ra values. Better surface Ra values can be achieved by selecting the proper processing time and rotational speed of the lapping plate. [ABSTRACT FROM AUTHOR]