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This study explores the effects of atomic-level factors on the performance of CeO 2 when interacting with SiO 2 films. It specifically examines how different precursors, the ratio of Ce to OH, and reaction temperatures influence outcomes. Our findings reveal that smaller particles, around 5 nm in size, created using a Ce4+ precursor, are more effective at removing SiO 2 films compared to larger, more crystalline particles from a Ce3+ precursor. This is due to their increased interaction with the SiO 2 film during the polishing process, challenging the conventional emphasis on mechanical abrasion in chemical mechanical planarization (CMP) and highlighting the crucial role of chemical interactions. Further analysis through FT-IR and TGA-FTIR techniques showed distinct functional group profiles on the ceria surfaces. Ceria derived from Ce4+ exhibited a higher presence of OH and NO 3 groups, enhancing adsorption capabilities, as verified by CHN analysis. Importantly, first-principles calculations identified these surface groups as key to improving adhesion to SiO 2 films. Surfaces of amorphous CeO 2 , rich in -OH and -NO 3 groups, showed significantly higher adhesion levels than their crystalline counterparts, connecting crystallinity to chemical functionality. This new insight leads to the possibility of designing next-generation CeO 2 abrasives with increased chemical activity. [ABSTRACT FROM AUTHOR]

Surface integrity—comprising abrasive embedding, work hardening, and residual stress—is crucial for the performance of nickel-based superalloy components milled by abrasive waterjet (AWJ). Effective evaluation of this integrity is therefore essential. First, the effects of pure waterjet and small-size AWJ on the milled surface were analyzed, with abrasive embedding as a key indicator. It was found that small-size AWJ significantly reduced both the number and depth of abrasive particles embedded. Next, single-factor experiments determined the influence of AWJ process parameters on abrasive embedding, leading to the identification of optimal modification schemes (modification scheme 1 and modification scheme 2) for minimizing the number and depth of abrasives. Recommended processing parameters are waterjet pressure = 100 MPa, and step-over distance = 0.38 mm. Finally, it was observed that both modification schemes decreased surface hardness while significantly increasing residual compressive stress compared to the unmodified surface. These findings offer a theoretical and practical foundation for achieving high surface integrity in the milling of nickel-based superalloys using AWJ. [ABSTRACT FROM AUTHOR]

The surface temperature of a workpiece during abrasive belt grinding directly affects its surface quality and determines whether the workpiece surface burns. However, the surface temperature of the workpiece during the grinding process is determined by the total heat and the heat carried away by the chips. Under certain grinding parameters, accurately obtaining the heat removed by the chips is one of the key factors to accurately obtain the workpiece surface quality. Therefore, a new method for chip heat monitoring based on audio-visual information decision fusion is proposed in this study. By obtaining visual sparks and sound signals directly related to the chip, a real-time chip quality (i.e., material removal rate, MRR) monitoring model based on convolutional neural network (CNN) and multilayer perceptron (MLP) was established. The heat taken away by the chips in real time was calculated through theoretical formula. The results show that the RMSE of the proposed method for the material removal rate does not exceed 0.006, and the coefficient of determination R2 is not less than 99.4%. The maximum error between the predicted maximum temperature of the grinding surface and the experimental measurement value is 10 °C. The proposed method provides the theoretical basis for the prediction and control of workpiece grinding temperature. [ABSTRACT FROM AUTHOR]

The solid particle erosive wear performance of basalt fiber‐reinforced epoxy composites with the incorporation of different percentages of milled carbon fiber fillers (0–10 wt%) is evaluated under various abrasive materials (garnet and ceramic beads) and impingement angles (30° and 90°). Erosion tests have been carried out following ASTM G76 standards using a factorial design method. The data indicate that the erosion rates, crater depths, and areas of craters are all strongly dependent on erodent material type and milled carbon fiber filler ratio. Compared to ceramic beads, garnet abrasives caused severe erosion, with erosion rates reaching approximately 500 mg/g at a 90° impingement angle without milled carbon fiber fillers. Erosion by both abrasives was significantly reduced by the introduction of milled carbon fiber fillers into the basalt fiber composites, with the erosion rate decreasing to around 100 mg/g with 3 wt% milled carbon fiber fillers. The maximum crater depth was also influenced; garnet abrasives produced craters as deep as 1000 μm without fillers at 90°, which was reduced to 451 μm with 3 wt% milled carbon fiber fillers when ceramic beads were used. Of the three factors for the erosion rate and crater depth, inorganic erodent material and ratio of carbon fiber filler were prominent, but the impingement angle effect was much smaller. Among the three factors for the erosion rate and crater depth, erodent material and carbon fiber filler ratio were prominent, while the impingement angle effect was significantly less. Highlights: The garnet abrasives cause more severe erosion than ceramic beads at 90°.Composites exhibit optimal erosion resistance with 3–5 wt% milled carbon fiber fillers.Filler ratio and erodent material type significantly impact erosion rates and depths.Factors affecting wear performance identified using factorial design and ANOVA. [ABSTRACT FROM AUTHOR]

Introduction: Non Carious Cervical Lesions (NCCLs) represent a prevalent dental condition characterised by the erosion of tooth structure at the cementoenamel junction without the involvement of dental caries. These lesions pose significant challenges due to their aesthetic impact, potential for dentinal hypersensitivity, plaque accumulation, pulpal complications and compromised structural integrity of the teeth. Tooth preparation traditionally uses diamond abrasive points and tungsten carbide burs for micromechanical adhesion. Newer methods, like ultrasonic tips, offer a more conservative approach, but limited research has compared their effects on bond strength, particularly in cervical cavity restorations with nanohybrid composites. Aim: To compare the surface roughness of cervical cavity preparations utilising diamond abrasive points and ultrasonic tips, and to evaluate the shear bond strength of restorations with composite resin. Materials and Methods: The present in-vitro comparative study was conducted in the Department of Conservative Dentistry and Endodontics, Guru Nanak Institute of Dental Sciences and Research, Panihati, Kolkata, West Bengal, India, from October 2023 to December 2023. The study included 52 freshly extracted maxillary 1st premolar teeth extracted for orthodontic reasons. These teeth were divided into two groups: Group-I (n=26) underwent surface preparation using a diamond abrasive point (No. 835-012, Piranha, SS White, USA), while Group-II (n=26) was prepared using an ultrasonic tip (Woodpecker G 20, Guilin Woodpecker, China). Teeth were cleaned, disinfected and stored in 0.1% thymol solution before being prepared with diamond abrasive points or ultrasonic tips, following which the specimens were restored using nanohybrid composite material (Solare X, GC Corporation, Japan). Surface roughness was assessed using a digital profilometer before the restoration, and the shear bond strength of repaired specimens was measured with a Universal Testing Machine. Statistical analysis was performed using GraphPad Prism, with independent samples t-tests applied to compare results between groups, and a significance level set at 5%. Results: Group-I exhibited greater surface roughness (6.33±2.18 μm) compared to Group-II (4.91±1.57 μm). Group-I also showed higher shear bond strength (62±13 MPa) than Group-II (59.3±19.9 MPa), though this variation was not statistically significant (p-value=0.56). Conclusion: Within the present study's limitations, diamond abrasive points created significantly greater surface roughness compared to ultrasonic tips. However, no statistically significant variations have been observed in shear bond strength among the two methods, suggesting that ultrasonic tips may be considered as an alternative to diamond abrasive points in clinical settings, avoiding their drawbacks while achieving adequate restoration retention. [ABSTRACT FROM AUTHOR]

Subsurface damage (SSD) structures induced by mechanical polishing of gallium nitride (GaN) substrates are comprehensively investigated using atomic force microscopy, cathodoluminescence (CL) imaging, and cross‐sectional transmittance electron microscopy. The low removal rate of the CMP process is a barrier to high productivity of a GaN wafering process; therefore, reducing the chemical mechanical polishing (CMP) process time by reducing the depth of SSD induced by mechanical processing is an active research area. To better understand the SSD structures, the surface roughness, SSD depth, and SSD distributions induced by mechanical polishing are quantitatively evaluated in this study. The SSD structures induced by mechanical polishing can be quantitatively exhibited as the SSD distribution with the damage strength at the outermost surface and the damage propagation, which are obtained by CMP process time‐resolved CL imaging method. On the basis of the analysis results, a schematic model of the SSD structures for mechanically polished GaN substrates is proposed. [ABSTRACT FROM AUTHOR]

The fabrication of micro-holes in hard-to-machine materials presents considerable challenges in precision machining. This study proposes a novel approach that employs high-strength micro-grinding tools with a central abrasive grain absence to create micro-holes through helical grinding. Due to the random distribution of abrasive grains, the absence of grains at the tool's center becomes an inevitable technical challenge. This research examines the correlation between the diameter of the absence zone and the bottom morphology of the machined hole, highlighting the potential formation of disc-shaped or cylindrical residues. A model for predicting the height of the disc-shaped residues is developed, and the mechanisms governing their removal during grinding are further explored. The findings indicate that when a central grain absence exists, the first abrasive grain surrounding the absence zone, referred to as the inner-edge grain, is responsible for removing the disc-shaped residues. Based on these results, a novel 0.8 mm diameter micro-PCD milling–grinding tool with a central edge absence is designed, and experimental validation is performed using 65% SiCp/Al composite materials. The experimental results confirm that the central grain absence leads to the formation of disc-shaped residues at the bottom of the machined hole during helical grinding, and the morphology of the experimentally obtained residues aligns with the theoretical predictions and simulations. This study significantly advances micro-grinding wheel technology and provides a solid foundation for the precision machining of micro-holes in hard-to-machine materials. [ABSTRACT FROM AUTHOR]

The machining accuracy and cutting ability of abrasive suspension jet (ASJ) are affected by the spatial volume distribution and velocity changes of jet flow and abrasives in the free jet area outside the nozzle. In this paper, large eddy simulation (LES) flow model, volume of fluid (VOF) multiphase flow model and discrete element model (DEM) were used to simulate the flow field characteristics of ASJ. The spatial volume distribution and velocity changes of jet flow and abrasives under 10 MPa jet pressure were studied and the model validation experiments were carried out. In the comparison between the numerical simulation results and the experimental results, it was found that the average error of the percentage of central jet flow is 3.4%, the percentage of central abrasive particles is 3.0% and the velocity of abrasive particles is 4.2%. The physical structure of the numerical model is fixed (so it does not support abrasive injection jet (AIJ)), and the material physical parameters, initial conditions and boundary conditions are editable. Therefore, it can be used to predict the degree of water divergence, abrasives divergence and abrasives velocity attenuation of ASJ with different jet pressure and abrasive types. This numerical model can provide guidance for the parameter setting of ASJ machining process in order to obtain better machining accuracy and cutting ability. [ABSTRACT FROM AUTHOR]

In aerospace, optical instrumentation, new energy, life science, and other fields, a large number of core components need ultra-precision polishing to obtain a high-quality inner surface, but polishing quality and efficiency are difficult due to mutual constraints. In order to polish the inner surface under both high quality and efficiency, a new soft abrasive rotary jet polishing (SARJP) method and system are proposed. Based on the polishing method and system proposed in this paper, an integrated multi-objective optimization algorithm model based on CatBoost and AGE-MOEA is proposed to realize the multi-objective prediction and process optimization of the roughness and material removal rate of the inner surface of a circular tube by SARJP. The lowest average absolute percentage error of surface roughness is 3.73%, and the largest average absolute percentage error is 6.49%, according to a comparison of the multi-objective optimization forecast findings with the experimental results. The minimum average absolute percentage error in the material removal rate is 3.72%, and the maximum average absolute percentage error is 8.28%. The initial surface Ra value of the inner surface of the circular tube is reduced by 94.99% from 211.16 to 10.57 nm, and the maximum material removal rate is increased by 15.83% from 5.234 to 6.218 mg/min, showing the effectiveness of the algorithm for prediction and optimization. [ABSTRACT FROM AUTHOR]

Non-conventional machining processes are capable of achieving higher performance compared to conventional ones due to their inherent characteristics and higher amount of parameters which can be favorably regulated. Although the correlation between the most important process parameters and process outcome has been already established for a wide range of conditions and workpiece materials, the introduction of new considerations related to the three pillars of sustainability require further investigation on new means for the enhancement of AWJ milling process. As one of the most important parameters in AWJ milling is the abrasive material, the introduction of new materials may offer considerable advantages from different perspectives. Thus, in the present work, a comprehensive investigation on the efficiency of using eco-friendly, mixed abrasives is carried out under various conditions such as different traverse feed rate, abrasive mass flow rate, water jet pressure, jet impingement angle, and mixing ratio. The feasibility of using mixed abrasives is evaluated in terms of achievable depth of penetration, kerf width, kerf taper angle as well as material removal rate (MRR), and cutting efficiency. The findings indicate that among other factors, the mixing ratio plays a noticeable role especially regarding MRR and cutting efficiency and can offer an additional effective means to achieve the desired kerf characteristics in conjunction with other significant parameters such as water jet pressure. [ABSTRACT FROM AUTHOR]

To solve the problem of severe rock pressure near coal mining face tunnels, a high‐pressure abrasive water jet slotting and roof breaking pressure relief technology is proposed. First, the laneway deformation mechanism and the process of hard rock slotting using high‐pressure abrasive water jets under long‐distance cantilever conditions are analyzed, and the crack initiation conditions of roof strata are obtained. Second, slotting tests under different slotting pressures, nozzle diameters, abrasive particle sizes and slotting times were carried out, and the slotting parameters of a high‐pressure abrasive water jet on a typical roof rock were obtained. Finally, industrial application was carried out in the 81,403 working face of Huayang No.1 Mine. After the hydraulic roof slotting measures were implemented in the test area, the maximum axial force of the anchor cable was reduced to 67 kN, which was 35.5% lower than that of the comparison. The average stress of the coal seam was 15 MPa, which was approximately 25% lower than that of the comparison. The deformation of the tunnel in the experimental area was significantly controlled, with an average movement of 30.0% toward the roof and floor of the tunnel and an average movement of 23.2% toward the two sides of the tunnel. Compared with the movement in the comparison section, the movement toward the roof and floor of the laneway was 42.3% lower, and the movement toward the two sides was 38.2% lower. The industrial application results show that high‐pressure abrasive water jet roof slotting and pressure relief technology can cut off the stress transmission path between the roof rock on both sides, effectively improve the stress state of the surrounding rock of the laneway, reduce the deformation of the roof, floor and two sides of the working face in the later stage of the mining laneway. [ABSTRACT FROM AUTHOR]

Silicon carbide (SiC) is a niche nonmetallic material that is essential in many industrial processes. Here, we integrate material flow analysis and supply chain resilience analysis to understand global SiC stocks and flows and to assess its supply chain. We use industry interviews to fill data gaps and collect information on the SiC system to overcome data scarcity. We find that globally around 1000 kt of SiC is produced each year. The biggest use of SiC is the abrasives industry (40%), followed by metallurgy (28%), refractories (20%), technical ceramics (0.7%), other uses (0.7%), and semiconductors (0.01%). As an energy‐intensive material, the SiC supply chain is under pressure, increasing the relevance of resilience considerations. Besides typical supply chain risks such as low diversity of supply and geopolitical trade restrictions, SiC particularly faces risks due to its energy‐intensive production process and associated emissions. In the SiC semiconductor supply chain, losses of nearly 75% are a particular issue. Due to high demand in the SiC market, stockpiles are negligible, and substitution is difficult in most sectors. We find that in the case of SiC, sustainability measures such as use reduction, recycling, or decreasing energy use or emissions would also positively contribute to supply chain resilience. This article met the requirements for a gold‐gold JIE data openness badge described at http://jie.click/badges. [ABSTRACT FROM AUTHOR]

Milling shallow-to-deep features in titanium alloy presents machinability challenges when a conventional process is employed. In this context, maskless milling by abrasive waterjet (AWJ) can be a better alternative due to its unique capabilities. Unlike conventional milling, assuming a linear summation of kerf cross-section profiles (CPs) while following the raster jet path, in AWJ milling will not yield an accurate prediction of surface geometry CP due to the nonlinearities involved in material erosion by multiple phenomena (e.g., reflected jets). The unavailability of measurement techniques for gaining insights into this complex AWJ interaction with the target at the milling zone for studying the flow behavior and the associated erosion hindered the development of accurate models for AWJ milling. This necessitates the need for the AWJ milling models that incorporate the abovementioned nonlinearities to yield reliable predictions. Towards this, the present work proposes a novel modelling framework to predict the geometrical characteristics (CP, maximum erosion depth (hmax), top width (WP), and CP area (AP)) of AWJ milled feature in Ti-6Al-4V alloy, considering pocket as a case study under varying jet's overlap percentage (JO%) and jet traverse rate (Vf). To get insights into the changes in the AWJ flow behavior and its interactions upon impinging the nonplanar target (NPT) post-first jet sweep and subsequent jet sweeps, computational fluid dynamics (CFD) simulations are performed. Results show an increasing asymmetric stagnation zone at the NPT relative to the planar target (PT), with the increased JO% and Vf leading to strong tangential flow, causing intense jet reflection and unwanted erosion. These understandings are utilized to mathematically model the unexplained erosion caused by the reflected jets, enabling accurate prediction of CP, hmax, WP, and AP. The proposed model accurately captured the nonlinearities that arose in hmax, WP, and AP with a maximum error of 10%, 11.8%, and 14.8%, respectively. In addition, the validated shapes of the pocket CPs result in an average mean absolute error of 42 µm, which agrees well with experimentally obtained ones. The validation results corroborate the hypothesis that the reflected jets caused upon impinging on the NPT compared to PT significantly contribute to unexplained erosion during milling other than the erosion due to the primary jets. [ABSTRACT FROM AUTHOR]

This essay primarily consists of an interpretation of The Anti-Christ, arguably Nietzsche's most abrasive and overall least appreciated book. By treating this late work as what it in fact is, on the other hand, namely, the culmination of Nietzsche's lifelong polemic against Christianity and the source of many of his most explicit and revealing pronouncements on what a "revaluation of all values" ultimately means, this essay argues that this work presents us not only with the philosopher's definitive position on Christianity, but with the real meaning of his thought as such. [ABSTRACT FROM AUTHOR]

Helical grinding is crucial for manufacturing small holes in hard-to-machine composite ceramics. This study introduces a geometric model of undeformed chips to analyze the cutting characteristics of abrasive grains on both the bottom and side edges of the tool. It reveals for the first time that the distribution of cutting grains—pure bottom-edge, pure side-edge, and mixed-edge—is influenced by the tool diameter and eccentricity. A novel calculation method for the distribution range (Dp) of pure bottom-edge grains is proposed, demonstrating that using a tool diameter at or below two-thirds of the target hole diameter effectively eliminates pure bottom-edge grains, improving chip evacuation, reducing chip adhesion, and optimizing cutting performance. Experimental validation on small holes in SiCp/Al composites (65% volume fraction) confirmed these findings and provides practical guidance for optimizing cutting parameters and tool design. [ABSTRACT FROM AUTHOR]

To improve the surface roughness (Ra) of the connecting rod journals of crankshafts and reduce polishing time for abrasive belt polishing machines, a method for optimizing the polishing process parameters for connecting rod journals is proposed, combining BP neural network and NSGA-II algorithm. Initially, factors affecting the surface roughness are screened, and in consideration of practical production requirements, a five-factor four-level orthogonal experiment is designed. A BP neural network is then used to establish a nonlinear mapping relationship between the polishing process parameters and the surface roughness of the connecting rod journals. The predicted results from the BP neural network are used as fitness values, and the NSGA-II algorithm is employed to obtain the Pareto frontier optimal solution set and the corresponding combination of polishing process parameters.According to the optimization results, the process parameters of the abrasive belt polishing machine model are modified as follows: polishing arm cylinder pressure of 0.8 MPa, rotational axis output speed of 140 rpm, abrasive belt model B with grit size 800#, Coolant type concentration of 9%, and polishing time of 20 s. In comparison to the initial scheme parameters of the abrasive belt polishing machine, this combination of parameters resulted in a 25.2% increase in surface roughness at the connecting rod journal and saved 20% of the polishing time. Through the process parameter optimization method in this paper, it will contribute to improving the production performance of the crankshaft abrasive belt polishing machine, effectively enhancing the surface roughness at the processed connecting rod journal and saving polishing time. [ABSTRACT FROM AUTHOR]

Surface roughness is a critical factor in restorative dentistry, as it influences both the esthetic and functional outcomes of dental materials. The choice of abrasive powders used during the air polishing of dental restorations can significantly impact the surface roughness, potentially affecting the longevity and performance of the restoration. This study aimed to compare the effects of three different air-polishing powders—sodium bicarbonate, erythritol, and glycine—on the surface roughness of a 3M Filtek™ Supreme XTE (3M St. Paul, Minnesota 55144-1000) United States composite resin and a Fuji™ IX glass ionomer cement. This study also examined how different application times (5 and 10 s) influenced these outcomes. Materials and Methods: An in vitro study was conducted using standardized blocks of 3M Filtek™ Supreme XTE composite resin and Fuji™ IX glass ionomer cement. Each material was treated with sodium bicarbonate, erythritol, and glycine at two different exposure times (5 s and 10 s) using a professional air-polishing device. Surface roughness (Ra) was measured before and after the treatments using a contact profilometer. The data were statistically analyzed using ANOVA and Tukey's post hoc test to compare the mean roughness values among the different groups, with a significance level set at p < 0.05. Results: The results showed significant differences in surface roughness between the materials, powders, and application times. The composite resin exhibited lower roughness and variability compared with the Fuji™ IX, indicating a more uniform and predictable surface. Sodium bicarbonate produced the highest roughness values, particularly after 10 s of application, while glycine resulted in the lowest roughness with greater variability. Erythritol produced intermediate roughness with moderate variability. For the Fuji™ IX, sodium bicarbonate caused the greatest variability in roughness, while glycine produced the smoothest surfaces. The ANOVA results confirmed significant differences in mean roughness among the abrasive groups, with Tukey's post hoc test showing that glycine had significantly lower roughness than sodium bicarbonate, and erythritol had higher roughness than glycine but was lower than sodium bicarbonate. Conclusions: This study demonstrated that the choice of air-polishing powder and application time significantly affected the surface roughness of both 3M Filtek™ Supreme XTE composite resin and Fuji™ IX glass ionomer cement. Glycine consistently produced the smoothest surfaces, making it a preferable option for clinical scenarios where minimal surface roughness is desired. Sodium bicarbonate, while effective in cleaning, resulted in rougher surfaces, particularly after longer exposure times. These findings suggest that careful selection of polishing powders can enhance the esthetic and functional outcomes of dental restorations, contributing to their longevity. [ABSTRACT FROM AUTHOR]

Gyrofinishing is a mass-finishing process used for large and/or complex workpieces. In this process, abrasive media filled in a container are accelerated by rotating the container, impacting the workpiece fixed in it and smoothing the workpiece surface. In this study, the effects of the materials and sizes of the abrasive media on the surface roughness, microstructure, and residual stress on the specimen surface developed by gyrofinishing were revealed. The surface of the gyrofinished specimen was smooth. However, the specimen surface when using the HS medium, consisting of a mixture of ceramic and small abrasive grains, was slightly rougher compared to that finished using the PS medium, consisting of ceramic. An ultra-fine grained structure was formed at the surface after gyrofinishing, regardless of medium. A flow of the microstructure was observed in the specimens gyrofinished with the HS media, indicating that shear stress occurred during gyrofinishing. All the gyrofinished specimens exhibited a significant compressive residual stress near the surface. The residual-stress profile along the depth direction differed depending on the material and size of the media. The small media shallowed the depth of the maximum compressive residual stress (dmax), whereas the medium size hardly affected the maximum compressive residual stress (·max). The measured dmax was significantly smaller than the dmax value estimated based on the Hertz contact theory, which is likely due to the shear stress generated by the rotation or sliding of the media on the specimen surface during gyrofinishing. The specimens gyrofinished using the HS series had a higher ·max than those gyrofinised using the PS series. The rough surface of the HS medium is expected to introduce a high compressive residual stress through the burnishing effect. It can be concluded that gyrofinishing provides the specimen surface with a smooth, ultra-fine grained structure and significant compressive residual stress. [ABSTRACT FROM AUTHOR]

Development of novel abrasive systems with functional activities and physicochemical properties are of great significance in the reactive oxygen species (ROS)-enhanced chemical mechanical polishing. In this work, Ce single-doped and Ce/Cu co-doped dendritic mesoporous silica nanoparticles (DMSNs), namely Ce−DMSNs and Ce/Cu−DMSNs, were produced via a simple impregnation and thermolysis procedure. The Ce and/or Cu species involved in DMSNs frameworks were characterized through X-ray diffractometry, infrared spectroscopy, scanning electron microscopy, energy dispersive spectrometry, transmission electron microscopy, X-ray photoelectron spectroscopy, and nitrogen adsorption/desorption techniques. We report the evolution of surface morphology and roughness, defects, peak-to-valley data, image surface area difference, and material removal efficiency during ROS-enhanced polishing experiments toward silica materials. All the pure, Ce single-doped, and Ce/Cu co-doped DMSNs abrasive systems offered nearly defect-free surfaces with close-to-atom scale roughness. It might be attributed to the "springlike effect" and "soft polishing/abrasion", possibly originating from the low-modulus DMSNs carriers. Among these abrasives, the Ce/Cu co-doped DMSNs systems achieved an evident improvement in removal efficiency, especially under ultraviolet irradiation-assisted polishing conditions. The coexisted Ce(Ⅲ)/Ce(Ⅳ) and Cu(Ⅰ)/Cu(Ⅱ) couples might be responsible for the effective production of ROS in photocatalysis and Fenton-like processes, thereby contributing to the Si–OH and Ce(Ⅲ)−O–Si bonding formations. The role of the developed Ce/Cu co-doped DMSNs abrasive systems in ROS-enhanced polishing processes was discussed. [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]

Management of waste materials is a serious concern to researchers and scientists. Waste materials cause health and environmental hazards. Hence, they should be properly managed. The aim of this study is to develop a grinding disc using agricultural wastes (palm kernel shell and snail shell), granite, aluminium oxide, and polyester resin. The particles of snail shell, palm kernel shell, aluminium oxide (abrasive) and granite (friction modifier) were measured in percentages varying between 8 - 29 wt. % and were mixed with 27 wt. % polyester resin (binder), 3 wt. % methyl ethyl ketone peroxide (hardener) and 3 wt. % cobalt naphthalene (accelerator) to produce a grinding disc. The micrograph, hardness, wear rate, and water absorption tests were carried out on the grinding disc samples. The result showed that the composition with the highest palm kernel shell particle content (29 wt. %) had the best values for hardness and wear resistance, making it the most suitable material for grinding discs. The environmentally-friendly palm kernel shell-based discs could be used for soft metals, wood grinding and finishing processes. [ABSTRACT FROM AUTHOR]

For space missions to either the Moon or Mars, protecting mechanical moving parts from the abrasive effects of prevailing surface dust is crucial. This paper compares the abrasive effects of two lunar and two Martian simulant regoliths using special pin-on-disc tests on a stainless steel/polytetrafluoroethylene (PTFE) sealing material pair. Due to the regolith particles entering the contact zone, a three-body abrasion mechanism took place. We found that friction coefficients stabilised between 0.2 and 0.4 for all simulants. Wear curves, surface roughness measurements, and microscopic images all suggest a significantly lower abrasion effect of the Martian regoliths than that of the lunar ones. It applies not only to steel surfaces but also to the PTFE pins. The dominant abrasive micro-mechanism of the disc surface is micro-ploughing in the case of all tests, while the transformation of the counterface is mixed. The surface of pin material is plastically transformed through micro-ploughing, while the material is removed through micro-cutting due to the slide over hard soil particles. [ABSTRACT FROM AUTHOR]

Rapeseed harvest cutting tools have been confined to large vibrations, entanglement, wear, and low efficiency. In this study, gas jet cutting was proposed for rapeseed stems using abrasive particles. This technique aimed to achieve the noncontact cutting between the machinery and the rapeseed, thereby ensuring efficient and low-consumption harvesting of rapeseed. The dynamic jet cutting of rapeseed stems was simulated using the smooth particle hydrodynamics-finite element method (SPH-FEM). The energy transfer between gas and solid phases was obtained for the dynamic behavior of the jet cutting. A test system was constructed to experimentally verify the jet cutting. The research results indicate that the maximum speeds of the airflow and abrasive particles were 741 and 411 m/s, respectively, when using a high-speed nozzle with a 4 mm diameter at a jet pressure of 20 MPa. Approximately 95% of the acceleration occurred in the throat and expansion sections. The external flow field of the nozzle exhibited a fluctuating pattern with the first decreasing and then increasing. The greater the jet pressure was, the more pronounced the velocity contraction and expansion fluctuations were. The jet beam primarily accelerated during gas expansion-contraction-expansion, thus converting the pressure into the kinetic energy of the jet beam. Once the inlet pressure increased from 3-10 MPa, the acceleration efficiency of the abrasive particles decreased from 31% to 11%. When the pressure exceeded 3 MPa, there was a further increase in the jet pressure, leading to a significant reduction in the efficiency of converting jet beam pressure energy to kinetic energy. At the same time, the maximum speed of abrasive particles with a diameter of 0.1 mm was 19% higher than that with a diameter of 0.3 mm. The larger the diameter of the abrasive particles were, the greater the cutting kinetic energy they obtained. Among them, 0.3 mm diameter abrasive particles exhibited the highest cutting kinetic energy, followed by 0.2 mm, and then 0.1 mm diameter. The minimum jet pressure of 0.4 MPa was required for the cutting rapeseed stems, with a lateral movement speed of 5 mm/s. Therefore, the stem was cut through in a single pass at a target distance of 10 mm. Once the lateral movement speed exceeded 5 mm/s, there was no cutting through in a single pass. When the jet nozzle was positioned 5 mm away from the target and the lateral movement speed was 5 mm/s, the minimum volume of cutting erosion was achieved in the incision widths ranging from 1 to 6 mm. The findings can also be applied to the cutting of similar crop stems. Theoretical and technical support can also be offered for the non-contact high-efficiency cutting equipment in modern agriculture. [ABSTRACT FROM AUTHOR]

To solve the problem that the surface of conventional CeO2 abrasive tools tends to glaze during the grinding process, water-resistant aluminum nitride powder (A/S powder) is added into abrasive tools to improve the self-sharpening ability. The effect of acetic acid content and sintering temperature on the water resistance of A/S powder is studied. The porosity, pre-grinding and mechanical properties of abrasive tools with different A/S powder content are tested. It is found that when the mixed A/S powder content is 9 wt%, there is no obvious glaze layer on the surface of abrasive tools, and the material removal rate is the highest. The result of grinding experiment shows that the glazing phenomenon is ameliorated and the surface roughness Ra and the flatness PV of quartz glass reaches 1.876 nm and 1.651 µm after the chemical mechanical polishing (CMP). [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]

This study presents a highly efficient chemical and magnetorheological fluid (C-MRF) hybrid polishing process established by using an eco-friendly slurry of malic acid, Fe3O4–SiO2 abrasive particles, and hydrogen peroxide (H2O2) as an oxidant, all mixed with purified water, highlighting its efficacy in a wide range of polishing applications. Herein, the polishing processes of Ti–6Al–4V alloy utilizing C-MRF with on Fe3O4–SiO2 abrasives are detailed, and the polishing performance is assessed by investigating the influence of oxidizing agent H2O2 and acid malic to the surface finish of the Ti–6Al–4V alloy. The linear variable magnetic field by improved Halbach array was proposed to improve the material removal rate and surface quality and create a polishing process with a highly efficient magnetic field source. Single-factor and orthogonal experimental analysis methods are applied to provide the technological parameters factors with varying influences on surface quality and material removal ability. [ABSTRACT FROM AUTHOR]

A novel polishing method is proposed to increase material removal rates through the acceleration of abrasive movements using micro-jets formed by spontaneous collapses of bubbles due to the cavitation in a special-shaped Venturi tube. The Venturi structure is optimized by numerical simulations. Process-related parameters for the optimal cavitation ratio are investigated for achieving maximum adaptation to polishing flat workpieces. Furthermore, this novel approach enhances processing efficiency by approximately 60% compared to traditional abrasive flow polishing. The processing method that employs cavitation bubbles within a special-shaped Venturi tube to augment the flow of abrasive particles holds significant potential for material polishing applications. [ABSTRACT FROM AUTHOR]

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Kodo millet (Paspalum scrobiculatum) is a minor millet with high nutritional properties and exhibits exceptional drought-tolerance and insect-resistance. But, the processing of this millet offers considerable challenges due to the presence of thick layers of hull. Hydrothermal pre-treatment before milling has been reported to reduce grain fragility and nutrient loss. The current study aims to assess the effect of hydrothermal pre-treatments on the dehulling, polishing, and nutritional characteristics of kodo millet. The grains were subjected to soaking (4, 6 & 8 h), steaming (10 min), and drying (till 12% moisture content) before polishing. The hydrothermally treated grain is polished by applying shearing and abrasion forces sequentially. The number of shearing passes (2, 4 & 6), and abrasive polishing time (20, 40 & 60 s) has been varied. Multivariate analysis has also been carried out to understand the correlation between different process variables. Results demonstrated that the treatment conditions significantly affect the dehulling and polishing efficiencies and the nutritional compositions of the grain. The increase in shearing and abrasion action increased the dehulling and polishing efficiencies, respectively. The study's findings could potentially be installed to increase the dehulling and polishing efficiencies while reducing grain losses. [ABSTRACT FROM AUTHOR]

Titanium alloys are employed extensively in some vital areas like aerospace, biomedical, and automotive due to their exceptional properties. Nevertheless, conventional grinding to process high-strength titanium alloys can be problematic and lead to burns and wheel clogging. As a new grinding method, high-shear and low-pressure grinding can effectively avoid these problems. In this study, a body-armor-like abrasive disc based on the principle of liquid body armor was developed to achieve high-shear and low-pressure grinding. The material removal mechanism of high-shear and low-pressure grinding with body-armor-like abrasive disc was revealed. The effect of some grinding parameters, such as spindle rotational speed, rotary table speed, and tool offset, on surface roughness, material removal depth, and material removal rate of Ti-6Al-4V alloy was discussed. The surface roughness (Ra) was reduced by approximately 85.3% from 313.8 to 46 nm under the optimal grinding parameters. A material removal rate of 2.648 µm/min was achieved. The surface morphology of the Ti-6Al-4V alloy before and after grinding indicated that the surface defects were substantially removed, with a concomitant improvement in surface quality. The results showed that the body-armor-like abrasive disc can achieve high-quality and high-efficiency grinding for Ti-6Al-4V alloy. [ABSTRACT FROM AUTHOR]

Silicon carbide particle reinforced aluminum matrix composites (SiCp/Al), combine the properties of aluminum matrix materials and reinforced silicon carbide (SiC) particles, finding widespread application in aerospace, optics, and electronics. The increased hardness and electrochemical inertness of SiC particles present significant challenges in their processing. This research investigates the impact of photocatalytic processes on machining accuracy in electrochemical processing (ECM). The dissolution characteristics of SiCp/Al during ECM and photocatalytic-assisted electrochemical machining (PAECM) were analyzed with varying electrolyte compositions, using polarization curves and oxidation–reduction potential (ORP). Validation of improved machining accuracy and surface quality in PAECM was achieved through no-feeding machining. According to theoretical principles and laboratory analyses of the workpiece surface, it was found that PAECM, through its photocatalytic reaction, generated more oxides, blocked stray currents and stray corrosion effectively, and attained accuracy in profile creation. Through a comparative analysis it revealed that PAECM exhibited smoother profiles and reduced Overcut Ratio (OCR) in hole and groove machining compared to ECM, particularly in groove machining. Adjusting machining gaps as well as reducing abrasive particle size in PAECM influenced groove depth and width, which achieved optimal morphology with a 0.4 mm gap and a 2–3 nm abrasive particle size, resulting in a 370 μm depth. [ABSTRACT FROM AUTHOR]

Being the final procedure in the blade shape processing, the material removal depth of abrasive belt grinding ultimately affects the blades' final shape precision and their servicing performance. The advanced blade material, single crystal superalloy, exhibits anisotropic mechanical characteristics, which adds complexity in blade material removal mechanism. In this work, based on crystallographic elastoplastic theory and abrasive belt's surface geometry, a microscopic penetration depth-contact force function is derived considering the anisotropic nature of the material through the multi-scale analysis of the contact between flexible wheel and the workpiece, Furthermore, combining with the dynamic contact zone profile, a flexible removal depth model of anisotropic materials is established. The proposed model was evaluated by the robotic belt grinding experiments. Experimental results demonstrate the model's excellent predictive capabilities. The results illustrate the significant effect of crystallographic anisotropy on MRD, and verified the tangential force and MRD predicting accuracies of the proposed model. [ABSTRACT FROM AUTHOR]

Si3N4 ceramic has the advantages of high hardness, high strength, corrosion resistance, and high-temperature resistance and is widely used in aerospace and other fields. As a hard and brittle material, it is prone to problems such as difficult control of processing surface quality and low processing efficiency. In order to explore the influence of the interaction between abrasive grains on the surface processing quality and processing efficiency of Si3N4 ceramic in rotary ultrasonic grinding, the multigrain grinding simulation is carried out to explore the removal mechanism of Si3N4 ceramic material under multigrain coupling. The multi-abrasive scratch test was carried out to verify the simulation. The results show that as the number of abrasive particles increases, the machining forces in both simulations and experiments increase. Meanwhile, the average grinding force per individual abrasive particle decreases. The maximum stress generated by grinding increases first and then decreases as the number of abrasive particles increases. As the number of abrasive particles increases, the depth of surface cracks and the average depth of scratches caused by grinding first decrease and then increase. [ABSTRACT FROM AUTHOR]

This work investigates the piercing of microholes in turbine shroud rings (Inconel-625) using the Abrasive Waterjet Cutting process. The concern with the hole piercing is the kerf angle caused by the attenuation of the jet energy and stand-off distance, which seriously impacts the processing precision of abrasive water jet piercing. The effects of piercing parameters like machining time (40, 60 and 80 s), abrasive mesh size (80 mesh and 120 mesh), stand-off distance (1, 2, 3 and 4 mm), abrasive jet pressure (100, 125, 150 and 175 MPa) are studied to reduce the kerf angle. The kerf angle increased linearly with a stand-off distance increase at different machining times. By piercing for 60 s and 80 s, the lowest values of kerf angle are obtained (0.03∘ and 0.02∘). The optimum conditions for making a pierced hole with a minimum kerf angle of 0.02∘ were achieved with a machining time- of 60 s, abrasive mesh size- of 20 mesh, and abrasive jet pressure- of Scanning electron microscope (SEM) images and visual measuring system (VMS) images are used to identify the surface characteristics in kerf zone. The features, including ploughing, particle embedment, lip impression and wear path due to the ductile mode of erosion caused by high energy impact, is also discussed. [ABSTRACT FROM AUTHOR]

This research aims to conduct the multi-response optimization for abrasive water jet machining (AWJM) of Aluminum 7075 metal matrix composites. The experiments were conducted with three levels of AWJM factors such as pressure, standoff distance, and traverse speed. The experiments were designed using Taguchi's L9 orthogonal array. The influence of AWJM parameters was assessed by measuring the outcomes like material removal rate, surface roughness, and taper angle. The single response optimization was obtained through Taguchi's signal-to-noise ratio analysis, and multi-response optimization was achieved with Taguchi–data envelopment analysis-based ranking (DEAR). From DEAR, the optimal AWJM parameter 180 MPa of pressure, 3 mm of standoff distance, and 40 mm/min traverse speed was found. After optimization, the surface roughness and taper angle were reduced by 5.44% and 10.92%, respectively. The influence of cutting parameters on the outcomes was examined through the analysis of variance. It was noted that traverse speed had a significant effect and a contribution of 47.79%. After AWJM, the surface was evaluated using SEM analysis, ploughing marks, ductile rupture, and a small crack were observed. [ABSTRACT FROM AUTHOR]

Organic–inorganic composites have important applications, especially in the area of bonded abrasives. They exhibit mechanical performances that cannot be achieved with organic materials alone and present an extremely stable performance, even at elevated temperatures. In this summary of our studies, we focus on the exceptional mechanical properties achieved by incorporating inorganic particles into a crosslinked matrix consisting of phenolic resin. A crosslinker such as hexamethylenetetramine reacts with the phenolic resins to form a stable 3‐dimensional matrix to "glue" the inorganic particles together. In order to achieve such uniform dispersion of the seemingly incompatible reacting components, a plasticizer, or wetting liquid, is usually employed. We have developed several environmentally appropriate wetting liquids that have proved to be superior to the traditionally used toxic substances. Some of the reactive wetting liquids used even enhanced the mechanical properties of the resulting composites by contributing additional crosslinks to the final reacted systems. A combination of techniques including the use of low‐field nuclear magnetic resonance has been used to characterize the curing process and assess the changes in mechanical properties at the molecular level. Detailed studies characterized the effects of moisture on the curing process and changes in mechanical properties. [ABSTRACT FROM AUTHOR]

Chip formation is considered one important indicator to evaluate machining processes. In particular, geometric features of chips may provide important insights for the assessment of machining stability and productivity. In fixed-abrasive machining processes, such as grinding and honing, chips are simultaneously produced by many of the geometrically undefined cutting edges. Despite being "undefined," geometric features of abrasive grains can still be statistically characterized or described. Accordingly, it can be assumed that, under stable machining conditions, the geometric features of abrasive chips may also conform to certain statistical patterns. However, statistical characterization of abrasive chips can be very challenging due to their large quantity, irregular shapes, minuscule size, and sometimes tangled condition. In this study, an analysis method combining metallographic preparation and micro-computed tomography (micro-CT) has been developed to characterize abrasive chips produced by a honing stone. The results regarding the geometric characteristics of the obtained massive abrasive chips, i.e., their sizes and shapes, were presented and statistically described. It was found most chips had a size around 50 µm and the shape being a slightly elongated and curved cone. Most of the geometric features could meet a positive skewness distribution. [ABSTRACT FROM AUTHOR]

Electrical discharge wire sawing (EDWS) is a hybrid processing method that can effectively remove craters and recast layers generated by discharges through the grinding action of abrasive grains. Under the same processing conditions, the material removal rate (MRR) of EDWS is higher than those of wire electrical discharge machining and fixed abrasive diamond wire sawing. A material removal model for EDWS is established based on the material removal mechanism of hybrid machining revealed in this study. An industrial camera was used to collect the wire saw status during EDWS, and image processing technology was used to obtain the wire saw deflection angle. The MRR for different process parameter settings is predicted using the established model. The effects of pulse width, feed rate, and wire velocity on the wire saw deflection angle and MRR were studied. Finally, the predicted results were verified through experiments. Results show that as the pulse width, feed rate, and wire velocity increases, the MRR increase. The order of impact on the wire saw deflection angle is feed rate > wire velocity > pulse width. In addition, the MRR predicted by the established model agrees with the experimental data, with a maximum error of 9.87%. [ABSTRACT FROM AUTHOR]

The existence of striations, and scratches in Abrasive waterjet (AWJ) cutting surface necessitates an exploration of these features for enhancing the cutting accuracy of AWJ machining. This article investigates surface roughness and micro-scratch morphology characteristics on brass cutting surfaces. According to the variation law of surface roughness values, the cutting section can be divided into three regions: the initial region, smooth region, and rough region. Numerous micron-scale scratches were observed in the cutting section. The scratch length, width, and depth values all show an increasing trend as the cutting depth increases, with the scratch length experiencing the greatest growth and variability. The influence of position and traverse speed on scratch size was studied using variance analysis. Furthermore, the length and width of the scratches on the cutting surface are significantly influenced by their position, accounting for 89.19% and 81.13%, respectively. Traverse speed had a minor effect on scratch length and width, accounting for 0.01% and 2.64% respectively. The depth of the scratches is influenced by their position on the cutting surface at a rate of 41.12%, while traverse speed had an impact of 38.10%. Finally, a mathematical method based on standard scores was proposed to assess the quality of the cutting section based on micro-scratch dimension. [ABSTRACT FROM AUTHOR]

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

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]

Inconel-625 is a high-performance nickel-based superalloy which offers exceptional properties such as extensive resistance to corrosion, high strength-to-weight ratio, hardness, and impressive heat tolerance. Machining precise holes with required dimensional accuracy is challenging in Inconel-625 using conventional drilling processes. The investigation aims to improve the quality characteristics of hole machined on Inconel-625 by using the abrasive aqua jet drilling (AAJD) process. The influence of jet pressure ( J P ), table feed ( T F ), mass flow rate ( M FR ) and gap distance ( G D ) on the erosion rate ( E R ), surface roughness ( R a ), circularity error (CIerror) and striation zone ( S Z N ) are investigated. The weighted principal component analysis (WPCA)-based response surface methodology (WPC-RSM) is employed to analyze and optimize process parameters. The optimal parameter settings ( J P -300 MPa, G D -1.5 mm, T F -64 mm/min, M FR -0.55 kg/min) are observed to produce substantial improvement in response. Comparing initial and optimal conditions, the surface roughness ( R a ) is decreased by 10.15% from 3.25 μ m to 2.92 μ m. The CIerror and S Z N are also reduced by 38.02% and 12.74%, respectively. The erosion rate ( E R ) is improved by 8.79% with the optimal settings. J P is found to be the most influential parameter, followed by M FR . Scanning electron microscopy (SEM) pictures and 3D roughness plots are used in the surface topography analysis. [ABSTRACT FROM AUTHOR]

Unsubmerged cavitating abrasive waterjet (UCAWJ) has been shown to artificially create a submerged environment that produces shear cavitation, which effectively enhances rock-breaking performance. The shear cavitation generation and collapse intensity depend on the pressure difference between the intermediate high-speed abrasive waterjet and the coaxial low-speed waterjet. However, the effect of the pressure of the coaxial low-speed waterjet is pending. For this purpose, the effect of low-speed waterjet pressure on rock-breaking performance at different standoff distances was experimentally investigated, and the effects of erosion time and ruby nozzle diameter on erosion performance were discussed. Finally, the micromorphology of the sandstone was observed at different locations. The results show that increased erosion time and ruby nozzle diameter can significantly improve the rock-breaking performance. At different standoff distances, the mass loss increases first and then decreases with the increase of low-speed waterjet pressure, the maximum mass loss is 10.4 g at a low-speed waterjet pressure of 0.09 MPa. The surface morphology of cavitation erosion was measured using a 3D profiler, the increase in both erosion depth and surface roughness indicated a significant increase in the intensity of the shear cavitation collapse. At a low-speed waterjet pressure of 0.18 MPa, the cavitation erosion surface depth can reach 600 mm with a roughness of 127 mm. [ABSTRACT FROM AUTHOR]

The structure and particle distribution of the abrasive used in chemical mechanical polishing (CMP) directly affect the performance of polishing and quality of the resulting surface. The ceria (CeO 2) nanomaterial has been extensively employed in polishing abrasives. Increasing the Ce3+ content is known to improve removal efficiency and enable optimal surface quality. In this study, we increased the Ce3+ content on the CeO 2 surface by growing CeO 2 nanoparticles in situ on graphene oxide (GO; CeO 2 @GO) to develop novel composite abrasives for the high-performance CMP of silicon wafers. The designed composite abrasive fully utilized the special structure of GO and the effect on the charge-transfer between CeO 2 and GO, which increase the Ce3+ content and number of chemical reaction sites available during the polishing process. This accelerates the generation rate of the oxide layer on the surface of the silicon wafer and increases the removal rate while improving surface quality. The removal rate of the composite abrasives reached 190.58 ± 13 nm/min, which is 50% higher than that of pure CeO 2 abrasives. Moreover, the average surface roughness (Ra) of 0.278 ± 0.07 nm within the confines of a 5.0 × 5.0 μm2 region was achieved using the novel composite abrasives. This study offers a straightforward method to enhance the content of Ce3+ in materials and provides a novel route for obtaining efficient composite abrasives. [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]

As a machining tool with great potential, abrasive water jet (AWJ) has been used extensively in cutting many types of difficult-to-cut materials. Actually, using AWJ to trim workpieces is another important application. Unlike other traditional machining tools, which do not make much difference in machining surface through cutting or trimming, the AWJ, a soft knife, would lead to a different shape profile on the machining side in the trimming process other than cutting. To explore the trimming process of AWJ, a specific method of modeling the shape profile of the machining side trimmed by AWJ is proposed in this paper. Firstly, a criterion has been built to classify whether it is a cutting task or an edge trimming task. After that, a series of experiments have been carried out to obtain how the AWJ cutting parameters affect the trimming process. Based on the experimental results, the key parameters affecting the trimming process have been found. Further, a mathematical model for trimming process has been built and its effectiveness has been verified through actual trimming. With this model, the shape error of the machining side trimmed by AWJ can be further reduced by adjusting the compensation parameters. [ABSTRACT FROM AUTHOR]

In the process of blisk polishing, path planning is a crucial approach to ensure machining efficiency and enhance polishing accuracy. However, existing path generation software does not take into account the large elastic deformation of the polishing tool and cannot guarantee consistent residual error after the processing path. To address these problems, a special effective methodology is proposed for developing an abrasive belt flap wheel (ABFW) polishing path, enhancing the polishing quality of the blisk. To this end, we first establish a motion envelope surface of the ABFW. Then, based on the radial material removal depth model of the ABFW, the amount of material removal is obtained at each contact point. Additionally, the maximum error minimization method is employed to iteratively optimize the solution, obtaining the polishing path for constant residual error. In the experiments, we find that compared to the polishing path generated by commercial software, the optimized polishing path is capable of achieving lower surface residual error and better surface quality. [ABSTRACT FROM AUTHOR]