Conventional Grinding Wheels Research Articles

Analysis and optimization of abrasive waterjet dressing parameters for surface texturing of diamond grinding wheels

With the development of ultra-precision machining technology, the grinding performance of diamond grinding wheels has put forward higher requirements. In this study, a new method of dressing diamond grinding wheels using abrasive waterjet (AWJ) technology is proposed to address the issues of workpiece damage and wheel clogging that occur when grinding difficult-to-machine materials with conventional diamond grinding wheels. The main process parameters were determined based on the theoretical model for dressing diamond grinding wheels using AWJ. The response surface methodology (RSM) and the backpropagation artificial neural network (BP-ANN) were employed to establish regression models between process parameters and microgroove characteristics. A comparison was performed to evaluate the prediction performance of both RSM and BP-ANN. The results indicated that both approaches BP-ANN and RSM are powerful tools for predicting microgroove characteristics. This work provides theoretical guidance for texturing diamond wheels surface.

Investigating a novel and highly efficient approach for the fabrication of diamond profile rollers using Wire Electrical Discharge Conditioning (WEDC)

The fabrication of high-precision and high-performance profile rollers represents the main challenge of utilizing profile rollers as dressers to condition conventional grinding wheels. This results in high demands for an efficient process to manufacture profile rollers (form dressing wheels). Conventionally, diamond profile rollers have been produced through infiltration or negative electroplating methods. Nevertheless, these manufacturing methods suffer significant drawbacks, including extended production times and substantial costs. This study presents an innovative approach to fabricating diamond profile rollers using Wire Electrical Discharge Conditioning (WEDC). The WED-Conditioning emerges as an effective alternative to profile metal-bonded rotary diamond dressing tools. This innovative method leads to the production of diamond profile rollers in significantly shorter timeframes and at a more economical cost compared to the conventional manufacturing method with comparable quality. The research delves into the influence of profile roller specifications and conditioning strategies on the achievable profile accuracy and topography of the profile rollers. Also, the wear behavior of the WEDC-conditioned profile roller over long-term conditioning of conventional grinding wheels was studied. The findings highlight the significant contribution of the appropriate selection of WEDC strategies to the profile accuracy, with the potential to achieve profile accuracies comparable with conventional profile rollers. As well, grain size emerges as the primary determinant of achievable profile accuracy for profile rollers. The findings of this study could provide insights into optimizing the manufacturing process for super abrasive diamond profile rollers, thereby enabling their widespread use in the grinding industry.

Optimal design and performance evaluation of grinding wheels with triply periodic minimal surface lattice structure

High-performance grinding wheels are critical tools for precision surface generation. In precision grinding processes, the coolant supply at the wheel-workpiece interface is critical for reducing grinding temperature and detrimental friction. For better lubrication and chip removal performance, the cavities or pores need to be generated throughout the grinding wheel. The ideal morphology of pores in grinding wheels should be inter-connected and capable of providing sufficient coolant. Conventional grinding wheel design and fabrication methods can only passively generate closed circular pores by using pore-forming agents. Increasing the percentage of pores in this way generally leads to an uncontrollable reduction in mechanical strength, while the closed pores are insufficient in cooling performance. In this paper, the grinding wheels with triply periodic minimal surface lattice structure are designed and fabricated, which achieves the regulable and inter-connected internal structure of grinding wheels. Meanwhile, to balance the relationship between the structural properties and performance indicators of porous grinding wheels, an optimal design method for the porous structure of grinding wheels is proposed. Finally, the grinding performance of the novel grinding wheels in comparison to electroplated diamond grinding wheels is investigated in terms of grinding force, specific grinding energy and ground surface roughness.

Electrochemical Weakening Material Strength for Accelerated Thinning of Silicon Carbide Substrates

This paper presents a novel approach to expedite the thinning of silicon carbide (SiC) substrates, a crucial step in enhancing material performance and extending chip longevity by reducing volume resistivity. The traditional methods of SiC substrate thinning, such as diamond wheel grinding and plasma etching, have inherent limitations, including the risk of wafer breakage and high processing costs. In response to these challenges, we propose an innovative technique involving the electrochemical etching attenuation of SiC strength, offering a cost-effective and efficient solution.In this study, we employed an electrochemical method to initially weaken the SiC substrate from the surface to a defined depth, followed by fine-tuning its thickness using a conventional diamond grinding wheel. Remarkably, our results demonstrate that SiC substrates subjected to electrochemical treatment exhibit well-structured lattices free from residual stresses. This novel approach not only reduces the risk of wafer breakage but also enhances the material's integrity (Figure 1).To gain deeper insights into the effects of electrochemistry on SiC material strength, advanced characterization techniques, including scanning electron microscopy, were employed. Our findings reveal that the electrochemically treated SiC surface exhibits a sponge-like morphology, with a cross-sectional profile showcasing prominent columnar structures (Figure 2). This sponge-like structure is attributed to the removal of silicon atoms during anodization, affirming the effectiveness of electrochemical methods in rapidly attenuating the material strength of SiC substrates, thereby facilitating their efficient thinning through grinding without compromising substrate integrity.In summary, this research highlights the potential of electrochemical methodologies for the initial weakening of SiC substrates, leading to accelerated and cost-effective thinning processes. This breakthrough not only expedites SiC substrate thinning but also contributes significantly to the advancement of SiC substrate thinning and grinding techniques, promising substantial benefits for future semiconductor device fabrication. Figure 1

Parametric design and performance evaluation of TPMS porous vitrified bond diamond grinding wheel using digital light processing

Porous vitrified bond diamond grinding wheels are commonly used for grinding hard and brittle materials. However, uneven pore distribution and low porosity affect the grinding performance of the wheel significantly. In this study, three types of triply periodic minimal surface porous vitrified bond diamond grinding wheels—Gyroid, Diamond, and Lidinoid–were prepared through parametric designing and digital light processing 3D printing. The grinding wheel achieved a uniform distribution and an interconnected pore structure. The key to high-performance grinding wheel via stereolithography 3D printing lies in the preparation of the slurry with high solid loading, low viscosity and uniform stability. Hence, the effect of surface modifiers on the slurry, along with the effect of sintering temperature and the microscopic and mechanical properties, was investigated. By grinding the SiC ceramics, the material removal rate, grinding temperature, and surface roughness were compared to those achieved using a conventional solid-structure grinding wheel. The results show that the slurry with the highest solid content of 80 wt% (58 vol%) and viscosity of 4.21 Pa s (30 s−1) can be prepared using surface-modified particles. The diamond grinding wheel sintered at 680 °C exhibits the best comprehensive performance. A grinding wheel prepared using stereolithography 3D printing can achieve better surface roughness and lower the grinding temperature.

Grinding performance of MgF2 ceramics using biomimetic shark fin grinding wheels with different structure parameters

In the field of precision machining, with the popularity of brittle and hard materials such as infrared windows, it has become difficult for conventional diamond grinding wheels to effectively perform high-quality machining. The structuring of traditional diamond grinding wheels using a pulsed laser is a key technology to effectively improve the grinding quality of grinding wheels. In this paper, three new shark fin diamond grinding wheels (SFSGW) with different slot widths are designed based on the excellent drag-reducing and channelizing properties of shark dorsal fins. The grinding performance of traditional grinding wheels (USGW) and SFSGW on magnesium fluoride ceramics was compared. The effects of SFSGW on the surface quality, surface roughness and wheel damage of the workpiece were investigated. The results showed that the surface roughness of ceramics after grinding by SFSGW was reduced by 22.15 % compared with USGW, and the surface quality was better. Proper construction increases the material removal rate of the wheel and improves the wear resistance and service life of the wheel.

Ultra-low damage processing of silicon wafer with an innovative and optimized nonwoven grind-polishing wheel

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 Sa 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.

Residual Stress Evaluation on Surface Grinding of Maraging 350 Steel with Conventional Sol-Gel Grinding Wheel

Residual Stress Evaluation on Surface Grinding of Maraging 350 Steel with Conventional Sol-Gel Grinding Wheel

Monitoring the dressing operation of conventional aluminum oxide grinding wheels through damage index, power spectral density, and piezoelectric sensors

Monitoring the dressing operation of conventional aluminum oxide grinding wheels through damage index, power spectral density, and piezoelectric sensors

Grain wear properties and grinding performance of porous diamond grinding wheels

Conventional diamond grinding wheels present challenges such as poor self-sharpening and difficulties in achieving ductile domain machining when processing hard and brittle materials, reducing machining quality and efficiency. This paper introduces a novel grinding wheel composed of porous diamond abrasive grains for better ultra-precision machining. Thermochemical etching is used to produce porous diamond grains of varying corrosion levels, and the cutting and wear mechanisms of these grains are investigated through molecular dynamics simulations and single-grain scratch tests. Compared to conventional diamond grains, the increased "micro-edge" and "multi-edge" features of porous diamond grains effectively reduce cutting force and heat. Notably, corrosion pore sizes ranging from 2 μm to 5 μm reduce cutting damage. Conventional diamond abrasive grains primarily incur damage through crystal surface dissociation and block crushing, whereas porous diamond abrasive grains experience damage mainly due to micro-crushing and micro-fracture. Ultra-precision grinding tests on 4H–SiC revealed that conventional abrasives produced cracks and pits on the grinding surface. In contrast, abrasives with a 2 μm eroded aperture exhibited predominantly ductile removal with minimal cracks and pits present. Abrasives with a 5 μm eroded aperture displayed desirable characteristics. This research offers valuable technical insights for enhancing the grinding performance of diamond wheels.

A comprehensive investigation of surface morphology during grinding of Inconel 625 using conventional grinding wheels

Grinding difficult-to-grind (DTG) materials such as superalloys have shown an upward trend for manufacturing high-precision and durable components. Superalloys, such as Inconel, have superior thermo-mechanical properties that allow them to withstand caustic working conditions and simultaneously make their grindability difficult. In this context, the present work investigates the grinding performance of Inconel 625 (IN 625) using conventional grinding wheels in dry condition. The current investigation uses the alumina wheel and the silicon carbide wheel to keep the cost factor minimum. The outcome of the experiments has been evaluated in terms of grinding forces and surface roughness. Advanced surface characterization techniques such as Scanning electron microscopy, X-ray diffraction, Raman spectroscopy and X-ray photoelectron spectroscopy have been employed to analyze the surface morphology of the ground surfaces produced by both wheels. It has been observed that the alumina wheel has performed much better than the silicon carbide wheel for a higher depth of cut. These observations have also been supported by wheel loading, in which loading for the silicon carbide wheel was approximately four times that of the alumina wheel. Moreover, long and flow types of chips produced by the alumina wheel indicate the better suitability of the alumina wheel while grinding IN 625. The findings of the present work are expected to provide an economical way of grinding IN 625, preferably using an alumina grinding wheel.

Finding optimum cutting conditions for augmented grindability of Ti-6Al-4V

ABSTRACT This study is dedicated toward subtractive manufacturing of difficult to process material, Ti-6Al-4 V through an extensively employed precision abrasive machining operation, grinding. Ti-6Al-4 V is the most extensively used material, which needs grinding during its finishing in many cases. However, grinding of the material is challenging due to the characteristics like high chemical reactivity at higher temperature, high hot-hardness, low elastic modulus, and low thermal conductivity. Due to elevated reactivity at raised up temperature, titanium tends to adhere to the abrasive wheel during grinding thus leading to ineffective cutting performance. Its low thermal conductivity intensifies thermal damage to the bonded abrasives forming glazed grits. The present experimental study deals with finding optimum cutting conditions for enhancing grindability of the alloy that involves optimizing the grinding infeed values for different conventional wheels. The optimized dressing infeed is used in the subsequent grinding operation where enhancement of grinding condition is investigated under the application of cutting fluids. The major considerations of the study are identifying coolants and delivery techniques, which follow sustainable developments, and suitable conventional abrasive grinding wheels.

ОСОБЕННОСТИ ПРОЦЕССА ОБРАБОТКИ СТАТИЧЕСКИ УПЛОТНЕННЫМИ АБРАЗИВНЫМИ СРЕДАМИ ДЕТАЛЕЙ ТИПА ТЕЛ ВРАЩЕНИЯ

The study objective is to find out an analytical dependence that correlates the operating parameters and the conditions of the finishing abrasive treatment with the roughness of the working surfaces of the parts, taking into account the shape factor of the manufactured parts.
 The tasks to which the paper is devoted include theoretical and experimental studies of the effect of the treated surface roughness on the technological modes and conditions of surface treatment of complex-profile parts in the medium of statically compacted loose abrasive, as well as in the development of a methodology for determining rational modes and conditions taking into account the shape factor of the machined parts and determining the achievable range of surface roughness.
 Research methods: theoretical studies are conducted on the basis of the main provisions of mechanical engineering technology, grinding theory, theoretical mechanics, theory of elasticity and plasticity. Experimental studies are carried out according to standard methods in production and laboratory conditions using certified instrumentation. The data obtained are processed using computer technology and presented in the form of empirical dependencies, convenient for practical use.
 The novelty of the work is in finding mathematical dependencies for calculating the pressure of a statically compacted abrasive layer on the surface of the parts being machined, taking into account the shape factor.
 Conclusions: Based on the calculated theoretical dependencies and experimental studies, it is shown that the work of micro-cutting with the microrelief of abrasive grains is approximately 1.5...2 times higher than the work of micro-cutting with the tops of abrasive grains of the grinding wheel. This allows to conclude that the machining of parts with a statically compacted loose abrasive, compared with grinding with a conventional grinding wheel, is a less energy-consuming process of removing material from the surfaces of the machined parts.
 The paper presents peculiarities of finishing parts with statically compacted abrasive media. The ratio of friction work and micro-cutting of the machining is shown. The nature of the contact interaction of abrasive grains with the treated surface is considered for the first time, taking into account the shape factor, and the rational range of final roughness is defined.
 The role of cutting elements of particles affecting the quality and productivity of machining is determined.

Investigation of the effects of speed ratio and transversal overlapping ratio on CVD form roller dressing of corundum wheels and subsequent grinding performance

Grinding operation performance is strongly affected by grinding wheel surface condition. Two of the main indicators of grinding behaviour are the ground part surface roughness and the consumed amount of energy, which are both affected by grinding wheel dressing operation. Researchers have deeply studied and modelled effects of dressing parameters for stationary and rotary dressers for vitreous-bonded corundum wheels, but there is still a lack of scientific knowledge on the effects of disc dressing parameters on grinding performance and on the ground part surface condition due the grater kinematical and dynamical complexity of the rotary dressing process related to the fact that both bodies are rotating. In this paper, a deep analysis of infiltrated CVD disc dressing efficiency for conventional grinding wheels will be presented, considering the influence of the combination of dressing parameters altogether. Specifically, the effects of a wide range of speed ratios (qd) and transversal overlapping ratios (Ud) will be tested, monitoring dressing and grinding indicators such as dressing forces and grinding power, as well as surface finish of the ground part. This work covers the whole range of speed ratios used in the industry, including those below −1.0 and above 1.0, an area that few researchers have dug into before. Furthermore, the impact of integer qnd ratios is explored, which is yet to be studied in the literature. Results show a high dependency of all analysed indicators on both analysed parameters (qd and Ud) and uncover the significance of taking into consideration the rotational speed ratio (qnd). Hence, findings can result in a useful tool for the selection of most suitable dressing parameters when specific surface qualities need to be achieved.

Wear assessment of microcrystalline and electrofused aluminum oxide grinding wheels by multi-sensor monitoring technique

Combining the manufacturing processes with a sophisticated monitoring system is becoming more frequent in industry, following the trend in ‘smart manufacturing’. Multi-sensor monitoring techniques can enhance the efficiency and precision of the manufacturing process. Although many studies have been focused on the grinding process, we are still a long way from a complete understanding, which represents a challenge to the scientific community. The aim of this research was investigate the wear behavior of microcrystalline aluminum oxide grinding wheels, in comparison with a conventional electrofused aluminum oxide grinding wheel, through acoustic emission (AE) monitoring and the use of force transducers. The difference between the two cases is that in the manufacture of microcrystalline aluminum oxide grinding wheels microcrystalline abrasive grains are added to the composition (representing 45 %). A specific experimental rig was assembled for the measurement of the grinding cutting force and AE during the external cylindrical plunge grinding process. Two specific material removal rates were selected for the grinding of nodular cast iron GGG70 workpieces. The experimental rig allows the radial grinding wheel wear to be determined employing an AE-based contact recognition procedure. The wear behavior of the grinding wheel is evaluated by correlating the ground workpiece surface roughness measurements with the post-process analysis of both the grinding force components and AE signals. The results show that the wear behavior of the grinding wheels was dependent on the specific material removal rate used and was characterized by micro and macro-wear mechanisms. It was found through the surface roughness measurements and process characteristics that the addition of microcrystalline aluminum oxide grains has a significant influence on the wear behavior of the grinding wheel. Specifically, the microcrystalline grinding wheel presented lower magnitudes of radial wear when compared to the electrofused grinding wheel. The proposed monitoring method can be widely used to evaluate the wear of grinding wheels during the grinding process.

A novel continuous indexing method for face-hobbed hypoid gear tooth grinding

Grinding is an important finishing process for gear teeth to eliminate the surface deformation after heat treatment and improve accuracy. Grinding face-hobbed hypoid gears is especially challenging because the extended epicycloid curve of the generating gear does not match with the circular curve of the conventional disc-type bevel grinding wheel. In this paper, we propose a novel tooth grinding method based on continuous indexing, which uses a conical grinding tool to replace the blade on the face-hobbing cutter head. It includes two types of generating motions between the conical grinding tool and the generating gear, and between the generating gear with the workpiece. The mathematical model is developed to determine the geometric parameters of the conical grinding tool and to avoid interference between the conical grinding tool and non-grinding flanks. Finally, a numerical example is presented and a computer numerical control (CNC) virtual experiment is conducted to validate the proposed method. The results show that the tooth surface accuracy can be effectively maintained.

Research on calculation of grinding surface roughness

In machining processes, grinding is often chosen as the final machining method. Grinding is often chosen as the final machining method. This process has many advantages such as high precision and low surface roughness. It depends on many parameters including grinding parameters, dressing parameters and lubrication conditions. In grinding, the surface roughness of a workpiece has a significant influence on quality of the part. This paper presents a study of the grinding surface roughness predictions of workpieces. Based on the previous studies, the study built a relationship between the abrasive grain tip radius and the Standard marking systems of the grinding wheel for conventional and superabrasive grinding wheels (diamond and CBN abrasive). Based on this, the grinding surface roughness was predicted. The proposed model was verified by comparing the predicted and experimental results. Appling the research results, the surface roughness when grinding three types of steel D3, A295M and SAE 420 with Al2O3 and CBN grinding wheels were predicted. The predicted surface roughness values were close to the experimental values, the average deviation between predictive results and experimental results is 15.11 % for the use of Al2O3 grinding wheels and 24.29 % for the case of using CBN grinding wheels. The results of the comparison between the predicted model and the experiment show that the method of surface roughness presented in this study can be used to predict surface roughness in each specific case. The proposed model was verified by comparing the predicted and measured results of surface hardness. This model can be used to predict the surface hardness when surface grinding

Optimizing the Sharpening Process of Hybrid-Bonded Diamond Grinding Wheels by Means of a Process Model

The grinding wheel topography influences the cutting performance and thus the economic efficiency of a grinding process. In contrary to conventional grinding wheels, super abrasive grinding wheels should undergo an additional sharpening process after the initial profiling process to obtain a suitable microstructure of the grinding wheel. Due to the lack of scientific knowledge, the sharpening process is mostly performed manually in industrial practice. A CNC-controlled sharpening process can not only improve the reproducibility of grinding processes but also decrease the secondary processing time and thereby increase the economic efficiency significantly. To optimize the sharpening process, experimental investigations were carried out to identify the significant sharpening parameters influencing the grinding wheel topography. The sharpening block width lSb, the grain size of the sharpening block dkSb and the area-related material removal in sharpening V’’Sb were identified as the most significant parameters. Additional experiments were performed to further quantify the influence of the significant sharpening parameters. Based on that, a process model was developed to predict the required sharpening parameters for certain target topographies. By using the process model, constant work results and improved process reliability can be obtained.

Analysis of the Cutting Abilities of the Multilayer Grinding Wheels-Case of Ti-6Al-4V Alloy Grinding.

This paper presents an effectiveness analysis of the grinding process with the use of a new multi-layer abrasive tool. The designed abrasive tool consists of external layers with a conventional structure, whose task is to decrease the grinding wheel load and ensure high grinding volumetric efficiency. The inner layer of the grinding wheel contains a 30% addition of abrasive aggregates. The task of the inner layer is to provide lower roughness of the machined surface. The aim of the research presented in this paper was to evaluate the topography of the designed abrasive tool and to analyze the middle layer properties influencing the machined surface roughness. The differentiation of the active surface features of the abrasive tool was determined for the conventional layer and the layer with the addition of abrasive aggregates. The machining potential of the layers was also determined using the Shos parameter. The surface topography of Ti-6Al-4V alloys ground with the use of a multi-layer wheel and a conventional grinding wheel was analyzed. With the application of the bootstrap hypothesis, the set of roughness parameters differentiating the topography of ground surfaces was determined.

Novel comparison concept between CBN and Al2O3 grinding process for eco-friendly production

Minimal Quantity of Lubrication was developed to achieve green manufacturing in machining process. In this study, parameters of cutting fluid flow, grinding wheel type and wheel cleaning system were evaluated to achieve the maximum potential of this technique in grinding process. The comparison of super abrasive (CBN) and conventional (Al2O3) grinding wheel, the cutting fluid flow (30 ml/h, 60 ml/h and 120 ml/h), and the wheel cleaning system were analyzed based on: surface roughness, roundness errors, grinding wheel wear, confocal of grounded surface, grinding power, acoustic emission and workpiece microscopy. In a novel way, this study compared the costs per piece and the carbon footprint in terms of CO2 emission for both abrasive tool application. For all the parameters analyzed, the CBN grinding with MQL outperformed the Al2O3 grinding, showing a superior performance not only in terms of surface finishing, on average, 29% lower surface roughness and dimensional deviation 9% lower but also regarding tool efficiencies, such as 127% lower diametrical wear, 42% lower acoustic emission, and 13% lower grinding power. Despite that, the cost per piece was also evaluated for the different lubri-cooling conditions and tools, and the cost per piece recorded for Al2O3 grinding was substantially lower than CBN grinding, irrespective of the lubri-cooling method employed. The cost of grinding for all MQL techniques analyzed with aluminum oxide wheel was, on average, 72% less than grinding with CBN wheel. Besides, the conventional method with the CBN wheel was 7% more expensive than the aluminum oxide wheel.