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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 work discusses challenges in conventional grinding wheels: heat-induced tool wear and workpiece thermal damage. While textured abrasive wheels improve heat dissipation, the current surface-only methods, such as those based on laser and machining, have high renewal costs. The proposed manufacturing technology introduces an innovative 3D cooling channel structure throughout the wheel, enabling various channel geometries for specific abrasive wheel applications. The production steps were designed to accommodate the conventional pressing and sintering phases. During pressing, a 3D organic structure was included in the green body. A drying cycle eliminated all present fluids, and a sintering one burnt away the structure, revealing channels in the final product. Key parameters, such as binder type/content and heating rate, were optimized for reproducibility and scalability. Wear tests showed a huge efficiency increase (>100%) in performance and durability compared of this system to conventional wheels. Hexagonal channel structures decreased the wear rates by 64%, displaying superior wear resistance. Comprehensive CFD simulations evaluated the coolant flow through the cooling channels. This new design methodology for three-dimensionally structured grinding wheels innovates the operation configuration by delivering the coolant directly where it is needed. It allows for increasing the overall efficiency by optimizing cooling, reducing tool wear, and enhancing manufacturing precision. This 3D channel structure eliminates the need for reconditioning, thus lowering the operation costs. [ABSTRACT FROM AUTHOR]

Polymeric resins are becoming increasingly popular in medical and engineering applications due to their properties, such as their low weight, high strength, corrosion resistance, non-allergenicity, and extended service life. The grinding process is used to convert these materials into desired products, offering high accuracy and surface quality. However, grinding generates significant heat, which can potentially degrade the material. This study investigates the grinding of acrylic-based resins, specifically focusing on the interplay between the grind zone temperature and surface finish. The low glass transition temperature (57 °C) of the acrylic necessitates the precise control of the grinding parameters (spindle speed, feed rate, depth of cut, and grinding wheel grain size), to maintain a low temperature and achieve high-quality machining. Thermal imaging and thermocouples were employed to measure the grind zone temperature under various grinding conditions. This study investigates the influence of four parameters: spindle speed, feed rate, depth of cut, and grinding wheel grain size. The best surface finish (Ra: 2.5 µm) was obtained by using a finer-grained (80/Ø 0.18 mm) grinding wheel, combined with slightly adjusted parameters (spindle speed: 11.57 m/s, feed rate: 0.406 mm/rev, depth of cut: 1.00 mm), albeit with a slightly higher grind zone temperature (~54 °C). This study highlighted the importance of balancing the grind zone temperature and surface finish for the optimal grinding of acrylic-based resins. Further, this research finds that by carefully controlling the grinding parameters, it is possible to achieve both a high surface quality and prevent material degradation. The research findings could be highly valuable for optimizing the grinding process for various medical and engineering applications. [ABSTRACT FROM AUTHOR]

Ductile iron is a heterogeneous material. The presence of spherical graphite and a hard and brittle structure makes the surface of the workpiece easily form pits and crack defects under harsh grinding conditions, which seriously affects the service life and service performance of the workpiece. The new assisted grinding process based on the electroplastic effect is expected to avoid the surface defects of ductile iron. By comparing the surface roughness and microstructure of conventional grinding and electroplastic-assisted grinding, the superiority of electroplastic-assisted grinding surface quality is confirmed. Further discussion is presented on the impact of grinding parameters on the workpiece's surface quality under the same electrical parameters. The results show that the sensitivity of surface roughness to grinding parameters from strong to weak is grinding wheel speed, feed speed and grinding depth. The optimal combination of grinding parameters is determined as a grinding wheel speed of 30 m/s, a feed speed of 0.5 m/min and a grinding depth of 10 μm. [ABSTRACT FROM AUTHOR]

In the field of precision machining, there are two widely used grinding methods for the same type of abrasive, namely, fixed abrasive grinding, and free abrasive grinding. In this paper, we utilized a self-developed rolling-sliding ratio controllable friction and wear testing machine to investigate the friction and wear properties of GCr15 bearing steel ground by fixed/free abrasive grinding under rolling and sliding motion, with varying abrasive particle sizes. The surface morphology and roughness of the ground bearing steel were observed and measured using a laser confocal microscope and white light interferometer. Results showed that under rolling and sliding conditions, the coefficient of friction for fixed abrasive grinding was higher than for free abrasive grinding. Under sliding conditions, the grinding efficiency of the fixed abrasive wheel is higher. However, in the case of wheel blockage, the grinding efficiency would significantly decrease. Conversely, the grinding efficiency of free abrasive grinding was observed to be stable throughout the grinding process. Under the same conditions of abrasive particle size in the sliding state, free abrasive grinding showed better surface integrity of bearing steel compared to fixed abrasive grinding. [ABSTRACT FROM AUTHOR]

Zirconia ceramic (ZrO2) has been widely utilized in industrial areas for its excellent physical and mechanical properties. It is essential to study the grinding effect and the parameters optimization, to achieve high efficiency and precision grinding. The response surface experiments of ZrO2 grinding are designed, where the grinding wheel speed, workpiece speed, and grinding depth are selected as the three grinding parameters. The experiment is carried out on a surface grinding machine with a diamond grinding wheel. The four response surface quadratic regression models are built for the grinding force, the surface roughness, the surface breakage rate, and the subsurface damage depth. Combined with the four regression models and the maximum undeformed chip thickness model, the effect of grinding parameters on the grinding results is comprehensively assessed. For the integrated minimum of the machining time and the four grinding results, the multi-objective optimization is carried out on the grinding parameters. The correctness of the optimization model is verified by experiment. [ABSTRACT FROM AUTHOR]

To distinguish the grinding performance of the multidirectional (MD) and unidirectional (UD) carbon fiber‐reinforced thermoplastic (CFRTP) composites, MD and UD carbon fiber‐reinforced poly‐etherether‐ketone (CF/PEEK) composites were employed in this study. Different ply stacking sequences and process parameters were set for grinding experiments. Subsequently, the surface morphologies and roughness were observed and measured. Experimental results indicated that the variations of grinding forces with grinding parameters of MD‐CF/PEEK and UD‐CF/PEEK were consistent. However, the heat transfer mechanism and the effects of grinding parameters on the maximum grinding temperatures were different between the two composites. The grinding forces and temperatures of MD‐CF/PEEK were slightly lower than UD‐CF/PEEK, and MD‐CF/PEEK reached better surface quality under the same parameters, indicating that the grinding performance of MD‐CF/PEEK was not the simple superposition of UD‐CF/PEEK. In addition, the chip formation and material removal mechanism of CF/PEEK were investigated. The grinding performance of MD‐CF/PEEK was primarily dependent on the θ elements of laminate while the grinding performance of UD‐CF/PEEK was closely related to the fiber orientation angles during grinding. This study established a more in‐depth understanding into the grinding performance of MD‐CF/PEEK and provided technical guidance for high‐quality grinding of CFRTP. Highlights: The grinding performance of the multidirectional (MD) and unidirectional (UD) carbon fiber‐reinforced poly‐etherether‐ketone (CF/PEEK) is compared.The grinding forces and temperatures of MD‐CF/PEEK are slightly lower than that of UD‐CF/PEEK, and the MD‐CF/PEEK reach a better surface quality under the same grinding parameters.The grinding performance of MD‐CF/PEEK is primarily dependent on the θ elements of laminate, and the change of layering order is not a critical factor.The grinding performance of UD‐CF/PEEK is closely related to the fiber orientation angles during the grinding process.The surface quality of MD‐CFRTP can be effectively improved by reducing the grinding depth and feed speed, and increasing the grinding wheel speed. [ABSTRACT FROM AUTHOR]

Silicon carbide (SiC) is ideal for making powerful, high-frequency chips for 5 G and electric vehicles due to its wide band gap and resistance to high voltage. However, its powerful chemical bond strength and extreme hardness make it difficult for die separation in the post-wafer process. A hybrid process technology is proposed, where die scribing is performed on SiC wafer using a femtosecond pulsed laser-assisted ablation. The extremely short energy pulses forced the ablation of traces of SiC at extreme speed, breaking chemical bonds and thereby reducing strength and hardness for easy high-speed cutting along the scribed lanes with a polycrystalline diamond wheel. The experiment showed that the average stage current dropped from 0.90 A to 0.45 A and kerf chipping ratio from 11.7 to 4.1 during die separation, proving that the process removed materials along the separation lanes using a wheel tool at low grinding force, creating separation lanes of outstanding straightness and minimal kerf chippings and SiC dies of high integrity. Furthermore, thanks to the on-line rotational machining and dressing of the wheel tool, the blunt diamond abrasive cutting edge could be redressed to expose chip pockets of appropriate depth and protruding grinding edges with a favorable negative rake angle. The established grinding regime utilizing a pressure-grinding force in cutting and material removal reduced cracking at the SiC surface. In this paper, the laser energy density, scanning speed, number of ablations, focus position, as well as the speed, feed-rate and grinding depth of the wheel tool are also discussed in detail. [ABSTRACT FROM AUTHOR]

While single-crystal diamond is a promising wide-bandgap semiconductor material, it is also the hardest material in nature and exhibits remarkable anisotropy, presenting a challenge for high-quality and efficient processing. To address this issue, this article introduces a method that utilises aluminium-coated nickel and diamond mixed abrasive vitrified bond grinding wheels for a mechanicochemical grinding process to reduce the anisotropic removal of diamond. Different cutting depths, abrasive ratios, grinding directions, and linear velocities were employed in the processing, with the material-removal mechanism studied through morphological characterisation, elemental content, and other detection methods. The experiment revealed that the catalytic effect of nickel metal occurred along the (111) crystal plane of the diamond. This catalytic process involves a transition from sp3 diamond to amorphous carbon, followed by graphitisation. The spin-rotating mechanicochemical grinding process mainly involves plastic removal in the soft direction and coupled chemical and mechanical removal in the hard direction. Employing this method reduced the surface roughness of the 7 × 7 mm as-grown crystal to Ra 0.467 nm, with a material removal rate of 4.73 μm/h, achieving a nearly damage-free machining surface. [ABSTRACT FROM AUTHOR]

Surface grinding is a widely employed finishing process in industrial sectors dedicated to achieve desired Surface characteristics of components. This study experimentally investigates the impact of the grinding parameters pertaining to the surface characteristics of Inconel 800, which is a nickel-iron-chromium alloy extensively used in high-temperature applications. Various commercially available grinding wheels were employed to grind Inconel800 under different grinding conditions. The ground surfaces were comprehensively analyzed using surface roughness measurements, Three-dimensional profilometry, optical microscopy, findings from XRD and SEM reveal that grinding parameters and wheel characteristics significantly impact the surface texture, topographical features, residual stress, and surface morphology of the machined nickel alloy.. The insights from this investigation contribute to the understanding of the grinding behavior of nickel-based superalloys and provide a basis for optimizing the grinding process for enhanced surface integrity. The findings are valuable for industries dealing with the machining of high-performance nickel alloy components. [ABSTRACT FROM AUTHOR]

The complexity of composite grinding movement, the variety of machining features and available grinding wheels, and the changing working conditions pose a challenge to the rapid programming of safe and efficient composite grinding procedure. The procedure optimisation plays an important role in solving this difficult problem. Therefore, a procedure optimisation method is proposed for composite grinding based on a Digital Twin (DT) system, which takes procedure time as optimisation objective to achieve high efficiency and ensures process rationality and safety by constructing corresponding constraint conditions. Moreover, the actual working conditions mapped into the DT system, such as workpiece parameters, machining requirements, grinding wheel parameters and status, machine tool motion position, and so on, are obtained to update the parameters involved in the optimisation model. And thus, the proposed method has the ability to timely find the optimal procedure under changing working conditions. In addition, a combination algorithm based on genetic algorithm (GA) and dynamic programming is proposed, which greatly reduces the search space of GA and realises the two-class co-optimisation of grinding wheel selection and procedure. Finally, the case study verifies the effectiveness of the proposed method to reduce procedure time and the dynamic response ability to changing working conditions. [ABSTRACT FROM AUTHOR]

Highlights Grinding could be used to enhance accuracy and quality of carbon fiber‐reinforced poly‐ether‐ether‐ketone (CF/PEEK) composites. However, the grinding mode, namely up‐grinding (UG) or down‐grinding (DG), is usually neglected while unbefitting grinding mode choice may cause inferior surface quality. To investigate effects of grinding modes on grinding performance of anisotropic CF/PEEK, grinding experiments in UG and DG were carried out under different fiber orientation angles θ. Experimental results indicated that maximum grinding temperatures and normal grinding forces in UG were lower than DG regardless of the abrasive grit sizes. Material removal mechanisms of CF/PEEK affected by grinding mode were revealed by analyzing morphologies of surface, chip and grinding wheel. When θ = 0°, the dominant mechanisms in DG were extrusion fracture and fiber deformation, while they were interface shear debonding and bending fracture in UG. When θ = 90°, the dominant mechanisms in DG included interface layer separation and bending fracture, while they were shear and extrusion fracture of well‐supported fibers in UG. Thus, UG was more favorable for material removal, obtaining lower surface roughness values, fewer machining defects and less wheel wear than DG. This study will provide technical guidance for high‐quality grinding of carbon fiber‐reinforced thermoplastic composites. The effects of grinding modes (DG and UG) on the grinding performance of anisotropic CF/PEEK composites were investigated. Material removal mechanisms of CF/PEEK affected by grinding mode were revealed under different fiber orientation angles. The maximum grinding temperatures and normal grinding forces in UG were lower than DG. UG was more favorable for material removal in grinding, and could produce better ground surface quality than DG. [ABSTRACT FROM AUTHOR]

Silicon is essential to the production of integrated circuits and optical components. Grinding is a commonly used method of silicon surface machining, but it often leads to surface and subsurface damage. These damages need to be removed by subsequent processes, typically through polishing. The surface quality generated by grinding directly impacts the cost of polishing. To enhance the quality of the grinding surface and reduce the time and cost of polishing, a grind-polishing wheel with a different structure from the conventional diamond wheel was developed. This wheel utilized ultrafine zirconia with grit size of 200 nm as abrasives and nonwoven as substrate to support the abrasives. Furthermore, to optimize the wheel and achieve better grinding performance, various wheels with different abrasive mass fractions and elastic moduli were fabricated and grinding experiments were conducted. The surface integrity of processed silicon and the material removal rate (MRR) were used to compare the grinding performance of the various wheels. After optimization, the MRR of the grind-polishing wheel reaches its peak at 0.81 μm/min. The silicon wafer ground with the grind-polishing wheel exhibited a surface roughness S a of 0.51 nm and a subsurface damage depth of 74 nm, which is close to the effect of chemical mechanical polishing processing. Compared to conventional diamond grinding wheel (mesh size of #5000), the optimized grind-polishing wheel is better suited for semi-fine finishing and can significantly reduce the cost and time of polishing. [Display omitted] • Grind-polishing wheel with ultrafine abrasives and nonwoven structure is developed. • The newly developed wheel produces silicon wafer with high surface integrity. • Relationship between wheel characteristics and grinding performance is revealed. • High MRR is obtained by optimizing the characteristics of grind-polishing wheel. [ABSTRACT FROM AUTHOR]

Tungsten heavy alloys (WHAs) have superior usage performance in various applications and are expected to be used as key components in nuclear energy, aerospace and precision instruments. As a strain-rate sensitive material, the material properties of WHA will change greatly with different grinding parameters during processing. However, most of the existing material removal models are established based on the static properties of the material. The precision grinding of WHA still lacks theoretical guidance. In this research, the effects of strain, strain rate, and temperature on the dynamic properties of WHA under high temperature and high pressure during face grinding are considered. The maximum undeformed chip thickness model for vertical-spindle face grinding with cup wheels is established. The relationship between the undeformed chip thickness, grinding quality, and grinding parameters was investigated. Experimental results show that the maximum undeformed chip thickness under the same conditions is 3.16 times smaller than conventional grinding, and the critical strain rate for ductile-brittle transformation is about 1.46 × 107 s−1. The grinding specific energy of WHA decreases with the increase of the maximum undeformed chip thickness and decreases with the increase of the material removal rate, reaching a minimum of 121.6 J/mm3. This study not only provides a new method for predicting the grinding condition of WHAs but also enhances the understanding of the cup wheel face grinding process and provides theoretical guidance for reducing the machining damage of WHA. [Display omitted] • The maximum undeformed chip thickness model (UCT) for the vertical-spindle face grinding (VSFG) is established. • The critical UCT model for VSFG considering the effects of strain, strain rate, and temperature is established. • The criterion for determining the ductile-brittle transition in tungsten heavy alloy grinding under VSFG is obtained. • The critical strain rate for ductile-brittle transformation is given. [ABSTRACT FROM AUTHOR]

The mechanical contact properties of M50 aviation bearing steel surfaces by using ultrasonic-assisted electrolytic in-process dressing (UA-ELID) grinding greatly influence the machined surface's quality. However, in wet grinding conditions, there are three contact forms on the grinding surface: the micro-cutting contact between the diamond abrasive particles of the grinding wheel and the workpiece surface, the sliding contact between the oxide film asperities on the grinding wheel surface and the asperities on the workpiece surface, and the hydrodynamic liquid film contact of the electrolytic grinding solution. The existing research on the mechanical behaviour of the grinding contact surfaces mainly focuses on the influence of one of the contact forms on the normal force. Therefore, calculation models of the dynamic solid-liquid mixing normal force of the UA-ELID grinding contact surfaces that with three contact forms are constructed in this paper to accurately understand the mechanical contact properties of the grinding surface. The relationship between the three contact forms under different process conditions, such as wheel speed, feed depth, and feed speed, and their influence on the normal force of the grinding contact surfaces are revealed. Finally, the accuracy and versatility of the calculation models in this paper are verified through comparative analysis with other normal force calculation model and experimental measurement. [Display omitted] • The contact mechanical models of grinding surfaces under the action of three contact forms were constructed. • The normal force generated by abrasive micro cutting is about 60% of the sliding contact of the asperities. • It reveals the shortcomings of the grinding specific energy normal force calculation model in the application process. [ABSTRACT FROM AUTHOR]

Given the low thermal expansion coefficient and excellent optical properties of fused silica in UV regions, it is widely used in lenses and other optical components. A precision grinding machine equipped with a cup grinding wheel has been employed for the aspheric grinding of spherical fused silica elements. This study aims to achieve two main objectives: firstly, to identify the contributions of feed speed and rotational speed ratio (RSR) on the profile and waviness errors of the workpieces and, secondly, to improve the prediction of profile errors by developing a high-fidelity data-driven machine learning framework. Accurate prediction of profile errors of the workpieces can be used to correct manufacturing errors. Furthermore, assessing the impact of input parameters on surface waviness errors is a viable approach to optimize the manufacturing process. Full-factorial experiments were designed for three levels of feed speed and RSR to find the sensitivity of modeling and predictions to these pertinent design variables. The trigonometric Fourier series model was used to fit form errors onto profile errors. The form errors evaluation revealed that RSR and the interaction between feed speed and RSR significantly affected the workpiece's form error. Reducing the feed speed led to a decrease in profile and waviness errors. The minimum waviness and profile errors were attained at an RSR of 50.25, regardless of the feed speed. The ensemble learning regression framework was subsequently trained using three sets of experimental datasets encompassing diverse combinations of RSR and feed speed values to model profile errors. While the profile model underwent validation on previously unseen segments of the datasets the network had been exposed to during training, the final tests were carried out using six datasets featuring entirely different profile errors that the networks had not seen before. The ensemble learning regression framework's performance tests were assessed using mean absolute error (MAE), mean squared error (MSE), root mean squared error (RMSE), and R-squared metrics. The framework demonstrated considerable predictive efficacy for the six left profile errors (unseen data), as evidenced by the calculated R-squared values from 0.767 to 0.965, signifying the lower and upper bounds of precision, respectively. • Study on profile and waviness errors induced by cup wheels in simultaneous 3-axis parallel grinding. • The rotational speed ratio and feed speed affect the workpiece form error. • The workpiece diameter significantly affects the workpiece profile error. • The trained, validated, and tested ML framework exhibited high fidelity and performance for predicting profile errors. • All six permutations without repetition were used to evaluate the ML framework. [ABSTRACT FROM AUTHOR]

SiC ceramics are typically hard and brittle materials. Serious surface/subsurface damage occurs during the grinding process due to the poor self-sharpening ability of monocrystalline diamond grits. Nevertheless, recent findings have demonstrated that porous diamond grits can achieve high-efficiency and low-damage machining. However, research on the removal mechanism of porous diamond grit while grinding SiC ceramic materials is still in the bottleneck stage. A discrete element simulation model of the porous diamond grit while grinding SiC ceramics was established to optimize the grinding parameters (e.g., grinding wheel speed, undeformed chip thickness) and pore parameters (e.g., cutting edge density) of the porous diamond grit. The influence of these above parameters on the removal and damage of SiC ceramics was explored from a microscopic perspective, comparing with monocrystalline diamond grit. The results show that porous diamond grits cause less damage to SiC ceramics and have better grinding performance than monocrystalline diamond grits. In addition, the optimal cutting edge density and undeformed chip thickness should be controlled at 1–3 and 1–2 um, respectively, and the grinding wheel speed should be greater than 80 m/s. The research results lay a scientific foundation for the efficient and low-damage grinding of hard and brittle materials represented by SiC ceramics, exhibiting theoretical significance and practical value. [ABSTRACT FROM AUTHOR]

Silicon carbide (SiC)-bonded diamond materials, comprising approximately 50% diamond by volume, represent innovative composites with exceptional mechanical and thermal properties, including high hardness, wear and corrosion resistance, and elevated thermal conductivity. Despite these advantageous properties, the machining of these composites presents formidable challenges due to their extremely high hardness. Grinding with diamond tools is commonly employed among the limited viable machining methods. However, the efficiency of this process is hindered by high grinding forces, elevated temperatures, and significantly high tool wear. Additionally, the surface integrity, form, and dimensional accuracy of the workpiece are compromised by the effects of tool wear and high cutting forces. To address these technological constraints in the grinding of SiC-bonded diamond materials, a laser-assisted grinding process has been developed. Ultra-short pulsed laser radiations were effectively utilized to induce material ablation with controlled structural damages, enhancing the productivity and efficiency of the grinding process through reduced grinding forces, temperatures, and tool wear. Furthermore, this study investigated the influence of grinding tools' specifications, design variations, and parameters on key aspects such as grinding forces, surface quality, and tool wear. Substantial reductions of up to 70% in tangential grinding forces, 83% in normal grinding forces, and a modest improvement in surface roughness achieved. The surface integrity analysis revealed a damage-free ground surface when utilizing laser assistance. Furthermore, there was a substantial enhancement in the grinding ratio (G-ratio), achieving an increase of up to 247%, concurrently with a noteworthy improvement in the actual removal depth, reaching up to 99%, when compared to conventional grinding processes. Compared to the utilized segmented metal bonded diamond grinding wheel, the vitrified bonded diamond grinding wheel induced lower grinding forces and higher actual removal rates. [ABSTRACT FROM AUTHOR]

The grinding process of transmission gear with worm grinding wheel usually relies on the manual parameter setting by experienced engineers, but the reliability and validity are quite hard to control due to many grinding factors that affect the surface quality (e.g. structure, size, and materials of gear, heat treatment process, surface accuracy requirements). Therefore, it is necessary to set up a decision system for assisting engineers with designing the process plan efficiently and reasonably. A modified model of the revision method based on the radial basis function (RBF) neural network and case-based reasoning (CBR) considering evaluation index was proposed in this paper. A similar case retrieval mainly relies on the soft likelihood function considering a compound evaluation index model, where the score value of each new case execution test is converted into the corresponding index to achieve effective case storage. Process solutions for similar cases that perform better will be recommended from the case database by means of CBR. These candidates can be revised systematically based on a self-learning model. A modified RBF neural network trained by the existing cases will apply the learned experience to revise solution in part or in whole, which utilizes a self-filtering attribute method based on the correlation coefficient matrix so as to gain the primary attributes. In the case of the grinding gear with worm grinding wheel, the applicability of this technology was demonstrated. A decision-making system applying this method was developed by using.Net framework4.0 and SQL Server. Consequently, the technique can quickly generate a feasible process plan for specific gear. [ABSTRACT FROM AUTHOR]

Grinding tools can be used for over 90% of their lifetime, but most practical production tools are replaced between 50 and 80%. Accurate tool condition monitoring, which can monitor the quality of grinding tools, can improve product quality and reduce costs. The transfer learning technique can solve the data distribution and data deficiency issues of deep learning methods, enabling precise tool condition prediction in a grinding system. However, selecting the optimal pre-trained model is crucial for enhancing transfer learning performance due to the relationship between the source and target domains and the negative transfer problem. To address this issue, an encoding metric-based model selection technique was developed that accurately reflects the time series similarity between the remaining useful life (RUL) of the grinding tool and the encoding value and features between the pre-trained model and target data. Encoding metrics that reflect the critical characteristics of transfer learning, such as the target label, data, and pre-trained model, were computed to assess the pre-trained models directly. The target RUL and the extracted encoding values from the target input data and pre-trained models were compared using measurements and correlation to evaluate how closely they matched. The encoding selection method demonstrated superiority over the current source selection criteria, with encoding-based root mean square error (RMSE), mean absolute error, and dynamic time warping showing a high association with the approach (over a Pearson correlation coefficient of 0.66). Furthermore, the method was independent of the quantity and quality of the sources, making it robust for various datasets. The experimental dataset was used to validate the pre-trained model's encoding RMSE selection method, and the method was verified with a strong correlation (Pearson correlation coefficient of 0.79). In conclusion, the proposed encoding metric-based model selection technique can improve both the efficiency and intelligence of the machining process in terms of both quantity (exchange periods) and quality of grinding tools. Accurate tool condition monitoring enabled by this technique can lead to enhanced product quality and reduced costs. [ABSTRACT FROM AUTHOR]

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

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

The drive at the center of gravity (DCG) concept-based twin-ball-screw drive mechanism (TBSDM) is vital in automated factories for its robustness and reliability. However, changes in the worktable mass or position result in changes in the center of gravity (CG), significantly affecting the system's dynamic properties. In this regard, this paper introduces a novel analytical model using improved receptance coupling to analyze vibrations in four modes. A mathematical framework for the twin TBSDM is generated, and the effect of changing the worktable position–mass on each mode is examined. The applicability of the proposed method is verified based on dynamic experiments that were carried out on a TBSDM of a CNC grinding wheel machine tool. After thoroughly analyzing the experimental and theoretical results, it is revealed that changing the worktable position primarily influences the rotational and axial vibrations of the twin ball screw (TBS). Furthermore, changes in the worktable mass significantly affect the coupling vibration among the TBSs and rotors or bearings. Moreover, in terms of performance, the variances between the theoretical and experimental natural frequencies are consistently below 5%. Thus, the proposed method is promising for the improvement of the modeling and analysis of the TBSDM. [ABSTRACT FROM AUTHOR]

In the study, the authors investigated the effects of picosecond laser ablation on the surface topographies of MONEL® alloy 400, used in the manufacturing of marine equipment components (such as pumps, valves, fixtures and fasteners). The experimental methodology involved preparing the material through grinding, polishing, and cleaning before subjecting it to picosecond laser ablation using specific parameters. The laser processing was carried out to create square ablated cavities on the alloy surface. The impact of the laser treatment on the surface condition of the alloy was assessed through profilometry analysis. The results provide insights into the surface topographies of the laser-treated MONEL® alloy 400 samples, offering valuable information for potential applications in marine industries [ABSTRACT FROM AUTHOR]

The use of CNC equipment that integrates several machining operations eliminates downtime due to changes in setup and clamping of workpieces in more than one machining device. A review of CNC equipment and tools known from the literature and from manufacturers' offerings indicates that new technical solutions are being developed to integrate two or more technological operations. However, these examples have numerous limitations and are mostly not suitable for machining surfaces with complex shapes. An example of such solutions is the use of a dual-tool grinding head, which integrates the process of rough grinding with a ceramic grinding wheel and finish grinding with a flexible grinding wheel. Unfortunately, it has the disadvantage of being limited by the angular shape of the ceramic grinding wheel, making it unable to adapt to the complex geometries of the shaped surfaces being ground. The need to overcome this limitation became the motivation for the research work described in this article. By means of experimental research, it was verified what effect the radial outline on the periphery of a ceramic grinding wheel realized by rough grinding would have on the surface roughness parameters obtained in the process of grinding shaped surfaces. For this purpose, grinding processes using a ceramic wheel with a conical and radial outline were compared. The result of the study was a summary of the surface roughness parameters Sa, St, Sq, Spk, Str, and Sds obtained after two-stage machining (rough and finish grinding). The obtained analysis results showed that changing the axial outline of the ceramic grinding wheel makes it possible to significantly expand the range of applications of the dual-tool head without negatively affecting the quality of the machined surface. Thus, such an improvement will make it possible to increase the applicability of the head by grinding shaped surfaces with a radial profile of curvature. [ABSTRACT FROM AUTHOR]

Due to its high melting point, tungsten carbide is perfect for mold-core usage during glass molding processes (GMP) such as those needed for manufacturing aspheric lenses. However, its extreme hardness makes it exceedingly difficult to machine. To overcome this problem, a BDD (boron-doped diamond) end-grinding-milling tool with dual-negative rake angle is designed and applied in this study to effectively mill a tungsten-carbide substrate. The first negative rake angle, with cutting edge across the tool's centerline, prevents squashing during cutting between tool point and mold-core surface. This suppresses brittle fracturing by cutting material under pressure-cutting force in the machining area. Further, when preparing the cutting tool, micro w-EDM was used to create micro-protrusion abrasives on the plane of the first negative rake angle that feature a different second negative rake angle, providing pressure in all directions during material removal. This feature ensured cutting occurred under a non-tensile-stress regime, which avoided microcracks and subsurface damage. Experiments have shown that the developed end-grinding-milling tool was successful in creating micro-flutes and an aspheric lens mold-core array. Surface roughness was nano-scale and there were no burrs nor chipping along mold edges, indicating the designed BDD end-grinding-milling tool is good for grinding-milling of superhard materials. [ABSTRACT FROM AUTHOR]

In silicon carbide processing, the surface and subsurface damage caused by fixed abrasive grinding significantly affects the allowance of the next polishing process. A novel grinding wheel with a soft and hard composite structure was fabricated for the ultra-precision processing of SiC substrates, and the grinding performance of the grinding wheel was assessed in this study. Different types of gels, heating temperatures, and composition ratios were used to fabricate the grinding wheel. The grinding performance of the grinding wheel was investigated based on the surface integrity and subsurface damage of SiC substrates. The results showed that the grinding wheel with a soft and hard composite structure was successfully fabricated using freeze-dried gel with a heating temperature of 110 °C, and the component ratio of resin to gel was 4:6. A smooth SiC substrate surface with almost no cracks was obtained after processing with the grinding wheel. The abrasive exposure height was controlled by manipulating the type and ratio of the gel. Furthermore, the cutting depth in nanoscale could be achieved by controlling the abrasive exposure height. Therefore, the fabrication and application of the grinding wheels with soft and hard composite structures is important for the ultra-precision processing of large-size SiC substrates. [ABSTRACT FROM AUTHOR]

Modular hobs are tools with very complex geometry. Regardless of the material of the gear wheels, they determine the accuracy of the gears made in the hobbing machining process. Gears are made of various, often innovative materials depending on the requirements. Sometimes, the materials are characterised by very high hardness (over 65 HRC). The mathematical basis for describing the faces of a hob presented in the article allows for modifying the rack profile shaping the gear wheel's teeth. The model's universality makes it possible to perform numerical simulations of the influence of individual parameters of the hob creation process (geometry of the grinding wheels and their setting in the shaping process) on the profile of the rake and flank surfaces. The cutting edge (rack edge) is the locus of points belonging to both of these surfaces and thus directly impacts the accuracy of the gear wheel that is shaped in the hobbing process. The article summarises the authors' long-term cooperation with the industry, resulting in a series of articles devoted to hobs. The issues presented in the article are significant to the machinery industry and hob manufacturers. [ABSTRACT FROM AUTHOR]

To analyze the mechanical performance of the arc end tooth connection structure, the optimization of electronic sensors based on the connection structure of double rotors with circular arc end teeth was studied. By designing and optimizing the structural dimensions of the arc end tooth, the relative position of the grinding wheel and the workpiece was determined, and the optimal electromagnetic actuator size, as well as the number and installation position of the optimized sensors, were obtained. The experimental results showed that the relative error of the rigid vibration mode of the arc end tooth double rotor connection structure was controlled within 10 %. At high speeds, the electromagnetic actuator had a significant control effect on the vibration of the centrifugal machine shaft. It diminished the vibration amplitudes in the X and Y directions by 37.6 % and 30.2 %, respectively. By optimizing the double rotor connection structure with circular end teeth and electronic sensors, effective control of the relative error of rigid vibration modes has been achieved, leading to significant reduction of the centrifugal shaft's vibration at high speeds. In addition, the sensor layout was optimized to enable real-time equipment vibration monitoring, ensuring equipment safety and stability. These achievements not only enhance the mechanical performance of the rotor system, but also provide important guarantees for the stability of the mechanical system. [ABSTRACT FROM AUTHOR]

Thin-walled bearings are widely used owing to the advantages of their light structure, high hardness, and strong load-carrying capacity. However, thin-walled bearings are often prone to deformation during the machining process, which can seriously affect the performance of the bearings. In addition, the machining deformation and quality of bearings are difficult to balance. To address the above issues, this paper investigates the effects of the machining parameters on the machining deformation, surface quality, and machining efficiency of a thin-walled bearing during the roughing stage. The dynamic balance between deformation inhibition and high quality in rough grinding was studied, and the optimal parameters for thin-walled bearing outer ring grinding were obtained. The deformation mechanism of thin-walled bearings caused by grinding was revealed through simulation and experimental analysis. The results show that the machining deformation and quality reach a balance when the workpiece speed is 55 r/min, the grinding wheel rotational speed is 2000 r/min, and the feed rate is 0.1 mm/min. Deformation increases with the increase in workpiece speed and grinding wheel speed. At the same time, the surface roughness increases with the increase in the workpiece speed, but the increase in the wheel speed will improve the surface roughness. As the workpiece speed increases, the surface topography shows a more pronounced stockpile of material, which is ameliorated by an increase in grinding wheel speed. As the rotational speed of the workpiece increases, the number of abrasive grains involved in the process per unit of time decreases, and the surface removal of the workpiece is less effective, while the increase in the rotational speed of the grinding wheel has the opposite effect. The grinding deformation of thin-walled bearings is mainly induced by machining heat and stress. As the rotational speed increases, the heat flux in the grinding zone increases. More heat flux flows into the surface of the workpiece, causing an increase in thermal stresses on the inner surface of the bearing collar, leading to greater deformation. The temperature in the grinding area can be reduced during machining, realizing a reduction in deformation. The research content contributes to the balance between high quality and low distortion in machining processes. [ABSTRACT FROM AUTHOR]

Monitoring the condition of the grinding wheel in real-time during the grinding process is crucial as it directly impacts the precision and quality of the workpiece. Deep learning technology plays a vital role in analyzing the changes in sensor signals and identifying grinding wheel wear during the grinding process. Therefore, this paper innovatively proposes a grinding wheel wear recognition method based on Variational Mode Decomposition (VMD) denoising and Aquila Optimizer—Convolutional Neural Network—Long Short-Term Memory (AO-CNN-LSTM). The paper utilizes Acoustic Emission (AE) signals generated during grinding to identify the condition of the grinding wheel. To address noise interference, the study introduces the VMD algorithm for denoising the sample dataset, enhancing the effectiveness of neural network training. Subsequently, the dataset is fed into the designed Convolutional Neural Network—Long Short-Term Memory (CNN-LSTM) structure with AO-optimized parameters. Experimental results demonstrate that this method achieves high accuracy and performance. [ABSTRACT FROM AUTHOR]

The influence of damping and friction performance of grinding wheels on precision grinding was explored for the first time. GO hybrid PU-modified PF copolymers were prepared by in situ synthesis and adopted as a matrix for fabricating grinding wheels. FT-IR, DSC, TG, and mechanical property tests showed the optimal modification when PU content was 10 wt% and GO addition was 0.1 wt%. Damping properties were investigated by DMA, and tribological characteristics were measured by sliding friction and wear experiments. The worn surfaces and fracture morphologies of GO hybrid PU–PF copolymers were observed by SEM. Distribution of components on the worn surfaces was explored by Raman mapping and EDS. The research results revealed that the PU component tended to be dispersed around the edges of corundum abrasives acting as a buffer layer of abrasive particles, which could provide micro-damping characteristics for abrasives, making the grinding force more stable during precision machining and facilitating a smoother surface quality of the workpiece. [ABSTRACT FROM AUTHOR]

Creep-feed grinding of high-strength steel is prone to excessive wheel wear and thermal damage defects, which seriously affects the service performance of parts. To solve the above-mentioned issue, a creep-feed grinding test was carried out on high-strength steel using SG and CBN abrasive wheels. The grindability of high-strength steel was scrutinized in terms of grinding force, machining temperature and grinding specific energy. Moreover, the effects of operation parameters and grinder performances on the surface integrity of the workpiece such as surface morphology, roughness, residual stress and hardness were rigorously studied. The results indicate that, when the instantaneous high temperature in the grinding area reaches above the phase transition temperature of the steel, the local organization of the surface layer changes, leading to thermal damage defects in the components. The outstanding hardness and thermal conductivity of CBN abrasives are more productive in suppressing grinding burns than the high self-sharpening properties of SG grits and a more favorable machining response is achieved. The effects of thermal damage on the surface integrity of high-strength steel grinding are mainly in the form of oxidative discoloration, coating texture, hardness reduction and residual tensile stresses. Within the parameter range of this experiment, CBN grinding wheel reduces grinding specific energy by about 33% compared to SG grinding wheel and can control surface roughness below 0.8 µm. The weight of oxygen element in the burn-out workpiece accounts for 21%, and the thickness of the metamorphic layer is about 40 µm. The essential means of achieving burn-free grinding of high-strength steels is to reduce heat generation and enhance heat evacuation. The results obtained can provide technical guidance for high-quality processing of high-strength steel and precision manufacturing of high-end components. [ABSTRACT FROM AUTHOR]

Titanium alloys have many excellent characteristics, and they are widely used in aerospace, biomedicine, and precision engineering. Meanwhile, titanium alloys are difficult to machine and passivate readily. Electrochemical grinding (ECG) is an ideal technology for the efficient–precise machining of titanium alloys. In the ECG process of titanium alloys, the common approach of applying high voltage and active electrolytes to achieve high efficiency of material removal will lead to serious stray corrosion, and the time utilized for the subsequent finishing will be extended greatly. Therefore, the application of ECG in the field of high efficiency and precision machining of titanium alloys is limited. In order to address the aforementioned issues, the present study proposed an efficient–precise continuous ECG (E-P-C-ECG) process for Ti–6Al–4V applying high-pulsed voltage with an optimized duty cycle and low DC voltage in the efficient ECG stage and precise ECG stage, respectively, without changing the grinding wheel. According to the result of the passivation properties tests, the ideal electrolyte was selected. Optimization of the process parameters was implemented experimentally to improve the processing efficiency and precision of ECG of Ti–6Al–4V. Utilizing the process advantages of the proposed process, a thin-walled structure of Ti–6Al–4V was obtained with high efficiency and precision. Compared to the conventional mechanical grinding process, the compressive residual stress of the machined surface and the processing time were reduced by 90.5% and 63.3% respectively, and both the surface roughness and tool wear were obviously improved. [ABSTRACT FROM AUTHOR]

Maraging steels are a family of Fe-Ni-Co-Mo alloys, and Ti addition to promote precipitation hardening with Ni and Mo. By adjusting the chemical composition and aging parameters maraging steels may be produced in classes of resistance from 200 to 400 ksi of ultimate tensile strength. As a concept, these alloys must present a combination of high strength and fracture toughness and are, for this reason, used in the manufacture of components and parts that must withstand large loads. Although maraging steels have good machinability as solution treated, the literature is scarce in studies on grinding machining processes of this type of steel with conventional grinding wheels. This work aims to analyze the results of residual stresses and surface finishing of maraging 350 steel machined by surface grinding process using a conventional sol-gel grinding wheel. Subsequently, the roughness of the machined surfaces was analyzed and residual stresses were measured by x-ray diffraction, using the sin2ψ method. The feed speeds increase in the range of 11-17 m/min contributed to a decrease in the magnitude of compressive residual stresses in the surfaces. The feed speeds and infeed did not exert a significant influence on the roughness results. [ABSTRACT FROM AUTHOR]

To enhance the surface quality of metal 3D-printed components, magnetic abrasive finishing (MAF) technology was employed for post-processing polishing. Experimental investigation employing response surface methodology was conducted to explore the impact of processing gap, rotational speed of the magnetic field, auxiliary vibration, and magnetic abrasive particle (MAP) size on the quality enhancement of internal surfaces. A regression model correlating roughness with crucial process parameters was established, followed by parameter optimization. Ultimately, the internal surface finishing of waveguides with blind cavities was achieved, and the finishing quality was comprehensively evaluated. Results indicate that under optimal process conditions, the roughness of the specimens decreased from Ra 2.5 μm to Ra 0.65 μm, reflecting a reduction rate of 74%. Following sequential rough and fine processing, the roughnesses of the cavity bottom, side wall, and convex surface inside the waveguide reduced to 0.59 μm, 0.61 μm, and 1.9 μm, respectively, from the original Ra above 12 μm. The findings of this study provide valuable technical insights into the surface finishing of metal 3D-printed components. [ABSTRACT FROM AUTHOR]

Magnetic elastic abrasive particles possess magnetism, low elasticity, and excellent grinding performance. Utilizing a double magnetic disk magnetic force tool for passivation can significantly enhance the efficiency and quality of passivation. Firstly, a mathematical model for the impact depth and volume on the tool is established. Secondly, using the simulation software ABAQUS, a simulation model is constructed to investigate the influence of grit size, quantity of abrasives, impact angle, disk rotation speed, and tool rotation speed on stress, energy, impact depth, and impact volume. Furthermore, the feasibility of the simulation and the reliability of the mathematical model are verified. [ABSTRACT FROM AUTHOR]

The current network for the dual-task grinding wheel defect semantic segmentation lacks high-precision lightweight designs, making it challenging to balance lightweighting and segmentation accuracy, thus severely limiting its practical application in grinding wheel production lines. Additionally, recent approaches for addressing the natural class imbalance in defect segmentation fail to leverage the inexhaustible unannotated raw data on the production line, posing huge data wastage. Targeting these two issues, firstly, by discovering the similarity between Coordinate Attention (CA) and ASPP, this study has introduced a novel lightweight CA-ASP module to the DeeplabV3+, which is 45.3% smaller in parameter size and 53.2% lower in FLOPs compared to the ASPP, while achieving better segmentation precision. Secondly, we have innovatively leveraged the Masked Autoencoder (MAE) to address imbalance. By developing a new Hybrid MAE and applying it to self-supervised pretraining on tremendous unannotated data, we have significantly uplifted the network's semantic understanding on the minority classes, which leads to further rises in both the overall accuracy and accuracy of the minorities without additional computational growth. Lastly, transfer learning has been deployed to fully utilize the highly related dual tasks. Experimental results demonstrate that the proposed methods with a real-time latency of 9.512 ms obtain a superior segmentation accuracy on the mIoU score over the compared real-time state-of-the-art methods, excelling in managing the imbalance and ensuring stability on the complicated scenes across the dual tasks. [ABSTRACT FROM AUTHOR]

Grinding technology exerts an enormous effect on the surface quality of double helical gears, which are subject to stringent requirements in the aviation industry. This study presents a novel gear-gap-space-borrowing grinding method that diverges from existing techniques. Unlike conventional approaches, this method mitigates the design–manufacturing conflict by exploiting the opposing gear gap space. By borrowing space, the grinding wheel's size can be enlarged to enhance machinability, diminish the width of the undercut, and align with the lightweight design imperative of double helical gears. The relationship between the grinding wheel diameter and the design parameters of double helical gears is analytically established, leading to the formulation of design rules. These rules facilitate the rapid selection of appropriate grinding wheel sizes for the space-borrowing method. Additionally, through geometric modeling and experimental validation, the optimal gear undercut width and the maximum wheel diameter are determined. The validity and accuracy of the proposed method are verified by simulations and experimental investigations. The study quantitatively evaluates the benefits of this method, including the expansion of the grinding wheel size, the reduction in double helical gear weight, and enhancements in processing efficiency and quality, providing a comprehensive comparison and discussion of these improvements. [ABSTRACT FROM AUTHOR]

In the article, the authors present the concept of a mathematical model used to study the influence of the properties of the base materials used to produce an innovative abrasive wheel background on the operating characteristics of the final tool. This model will be used to verify various material and construction solutions. The article also covers the outcomes of research that confirm the developed model’s effectiveness in relation to the operation of lamellar grinding discs, as per their intended technological goal. The experiments involved surface grinding with grinding wheels constructed on chosen backgrounds. A dedicated research stand was designed to measure the temperature in the grinding zone without direct contact, using both new and used grinding discs. The tests incorporated various load levels applied by the grinding disc on the workpiece, as well as different working angles of the grinding disc. [ABSTRACT FROM AUTHOR]

Due to the continuously growing demands from high-added-value sectors such as aerospace, e-mobility or biomedical bound-abrasive technologies are the key to achieving extreme requirements. During grinding, energy is rapidly dissipated as heat, generating thermal fields on the ground part which are characterized by high temperatures and very steep gradients. The consequences on the ground part are broadly known as grinding burn. Therefore, the measurement of workpiece temperature during grinding has become a critical issue. Many techniques have been used for temperature measurement in grinding, amongst which, the so-called grindable thermocouples exhibit great potential and have been successfully used in creep-feed grinding operations, in which table speed is low, and therefore, temperature gradients are not very steep. However, in conventional grinding operations with faster table speeds, as most industrial operations are, the delay in the response of the thermocouple results in large errors in the maximum measured value. In this paper, the need for accurate calibration of the response of grindable thermocouples is studied as a prior step for signal integration to correct thermal inertia. The results show that, if the raw signal is directly used from the thermocouples, the deviation in the maximum temperature with respect to the theoretical model is over 200 K. After integration using the calibration constants obtained for the ground junction, the error can be reduced to 93 K even for feed speeds as high as 40 m/min and below 20 K for lower feed speeds. The main conclusion is that, following the proposed procedure, maximum grinding temperatures can be effectively measured using grindable thermocouples even at high values of table speed. [ABSTRACT FROM AUTHOR]

Optical glass BK7 is an amorphous crown glass widely used in the aviation industry and high-power laser equipment due to its mechanical and optical properties. With the hard surface and brittle nature, the grinding process is one of the standard machining methods of BK7. Fracture is a dominant mechanism in removing brittle materials, which causes surface and sub-surface defects in the workpiece. Prediction of the depth of sub-surface damage (SSD) that has occurred allows the optimal reduction or even elimination of sub-surface defects in the finish grinding stage. This research aimed to comprehensively investigate the multifaceted influence of seven pertinent parameters on the depth of sub-surface damage (SSD) and surface roughness (SR) resulting from the grinding process. More specifically, it delved into the effects of the grinding wheel's movement direction under varying contact conditions, including angular grinding, vertical grinding, and face grinding, focusing on three critical aspects: the maximum undeformed chip thickness, depth of sub-surface damage, and resulting surface roughness. The contact conditions between the grinding wheel and the workpiece were systematically classified into four groups based on predetermined input parameters to facilitate in-depth analysis. Subsequently, the resulting outputs were evaluated and compared across these diverse contact conditions. The comparative examination between theoretical equations and experimental findings unveiled a maximum deviation of 10 % in SSD depths and 15.61 % in SR estimations. Furthermore, this study's experimental assessments identified nonlinear and monotonic relationships between the depth of SSD, surface roughness, and the maximum undeformed chip thickness (h m). The experimental relationships and the measured results notably highlighted observed discrepancies of 4.27 %, 10 %, and 10 % for the respective parameters (SSD, surface roughness, and h m). • The effect of the spiral speed on the surface and subsurface defects had not been evaluated with the cup grinding wheel. • Maximum undeformed chip thickness (h m) relations were modified based on the grinding conditions. • The SSD depth and the SR value in four grinding conditions with cup wheels were theoretically and experimentally evaluated. • The SR values and SSD depth can be changed according to the workpiece radius based on the grinding conditions. • Monotonic non-linear relations are obtained based on the experimenral results to calculate SSD depth in terms of SR value. [ABSTRACT FROM AUTHOR]

The efficiency and form accuracy of micro-structured surface preparation can be greatly improved by using structured wheels to grind micro-structured surfaces. In this study, the structural design of the grinding wheel surface was first carried out. Then, the geometric analysis of the designed structured 3D model of the grinding wheel is carried out to establish a numerical model for grinding micro-structured surfaces with structured grinding wheels and to investigate the effects of different velocity ratio, grinding depth and dressing angle on the size and distribution of surface microstructures. Finally, the surface of the grinding wheel is structured using wire electrical discharge machining (WEDM) technology, and the microgroove grinding experiment on the sapphire surface is carried out. The research results show that the established numerical simulation can accurately describe the formation mechanism of micro-structured surfaces ground by structured grinding wheels. At the same time, it is found that the shape of micro-grooves on the sapphire surface ground by the structured grinding wheel is basically complete. This further shows that the technology developed in this research can produce the micro-structured surfaces with good quality. • Numerical modeling of microstructure formation mechanism on grinding surfaces of structural grinding wheels. • Preparation of microgroove arrays on the surface of grinding wheels by WEDM technology. • High-quality sapphire surface microstructures prepared using structured grinding wheels. [ABSTRACT FROM AUTHOR]

Grinding process can achieve minimal material removal quantity and multiple material removal mechanisms simultaneously, which makes it extremely popular in industrial applications to meet the requirements of high dimension precision, excellent surface quality and rigorous tolerance. However, due to the randomly-sized and randomly-distributed abrasive grains, an accurate ground surface prediction model remains a significant challenge by considering the actual microstructure of grinding wheel. This research aims to develop a novel surface prediction model to take into account the random nature of the grain size and its distribution in grinding wheel. The generation of ground surface is modeled by calculating the transient trajectory of grain in the whole contact zone. Micro grain-workpiece contact mechanism is revealed in terms of the typical stages of rubbing, plowing and cutting to determine the ground surface morphology. Grinding experiments were performed to compare with the predicted surface morphologies. The proposed model was further validated in the terms of surface topography, roughness and material removal rate. Additionally, material removal mechanism associated with surface generation has been explored by the predicted ground surface and material removal rate under different grain-workpiece interaction states. The provided model is further employed to examine the impact of the randomness of grain size and distribution and grinding parameters on the surface roughness. Thus, the research provides fresh insights into understanding the underlying mechanism in different grain stages as well as revealing the transient contact mechanisms in generating ground surface integrity. [Display omitted] • Surface prediction model is established based on the micro multi-grain material removal stages. • Surface generation considers the effect of the random nature of grain size and distribution. • Surface generation evaluates the impacts of plastic side flow and elastic recovery in grinding. • The model was validated by experiments in term of ground surface and material removal rate. [ABSTRACT FROM AUTHOR]

The coarse-grained electroplated diamond grinding wheels is increasingly favored in precision grinding of hard and brittle materials owing to its high material removal efficiency, high wear resistance and steady surface contour accuracy. However, how to determine whether the dressed grinding wheel surface topography can achieve the desired precision ground surface quality is still a huge challenge to this day. In this paper, a novel numerical simulation model, which was established basing on the statistical features of actual electroplated coarse-grained diamond grinding wheel and the kinetics of the grinding process, was proposed for theoretically and thoroughly studying the influence of the surface dressing depth of coarse-grained electroplated diamond grinding wheel on ground workpiece surface morphology. At first, the statistical features of actual electroplated coarse-grained diamond grinding wheel was acquired and a novel numerical grinding wheel surface model was established. Subsequently, a numerical ground workpiece surface simulation model was also developed. And then, the evolving mechanism of the grinding wheel surface topography with the dressed wheel surface abrasive grain protrusion height was theoretically studied by numerical simulation. Moreover, the influence of the wheel surface abrasive grain protrusion height on the ground surface roughness was thoroughly researched by means of theoretical model and experiments. The simulation and experiments results in this paper indicated that precision ground workpiece surface with nano-scale surface roughness can be acquired by grinding with a dressed grinding wheel with a certain abrasive grain protrusion height of 25% of the typical abrasive size. Comparing with the undressed grinding wheel (grinding wheel with original surface topography and not be dressed), the surface roughness Sa and Sq of the surface ground with a well-dressed wheel can achieving a significant decrease of 97.75–99.77% and 97.57–99.73%, respectively. Therefore, carefully dressing the electroplated coarse-grained diamond grinding wheel is of great significance for obtaining a precision ground workpiece surface quality. [ABSTRACT FROM AUTHOR]