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The need for eco‐friendly cooling materials and material recycling are two urgent challenges to address. In this paper, the role of the ground tyre rubber treatment (cryo‐grinding and devulcanization) is investigated on the tensile and elastocaloric properties of Natural rubber (NR)/ ground tyre rubber (GTR). The GTR particles that are sieved (<63µm) and devulcanized by microwave irradiation (1 min at 800Watts) exhibit a low network chain density (0.53 × 10−4 mol.cm−3) resulting from crosslinks breakage and rubber chains scission, as supported by FTIR showing a decrease of S─S, C─S, and C─C bonds. The NR/GTR blends show a high elastocaloric effect as compared to the pristine NR, which can be ascribed to the high content of carbon black in the GTR (52 wt.%) and also the high level of devulcanization of the GTR. NR/GTR blends reach a heating of +8 °C and a cooling of >−6 °C, resulting in a material's coefficient of performance COPmat = 2.8–3 compared to 2.6 for the pristine NR. The concomitant effect of cryogrinding and microwave devulcanization is proposed as a way to improve the tensile and elastocaloric properties of natural rubber/waste rubber blends for their possible integration into elastocaloric devices for heating/cooling applications. [ABSTRACT FROM AUTHOR]

The objectives were to determine the interactive effect of particle size of soyabean meal (SBM) and whole wheat, barley and wheat bran (CER) on growth performance of weanling pigs after an enterotoxigenic Escherichia coli F4 challenge (Experiment 1) and on gastrointestinal (GIT) development immediately after weaning (Experiment 2). Experiment 1 consisted of 192 pigs (24 ± 3 days of age; 7.4 ± 1.1 kg weaning bodyweight [BW]) selected for Escherichia coli (E. coli) F4 susceptibility. Pigs were given an oral E. coli inoculum at postweaning day 7, to induce an enteric health challenge. Experiment 2 consisted of 40 pigs (24 ± 3 days of age; 7.2 ± 1.0 kg weaning BW) that were killed on postweaning day 8 or 9, to determine the effects of particle size on GIT development and functionality. Four experimental diets were used in a 2 × 2 factorial design: (1) coarse CER and coarse SBM, (2) coarse CER and fine SBM (CERcSBMf), (3) fine CER and coarse SBM, or (4) fine CER and fine SBM (CERfSBMf). Results showed no interaction between SBM and CER coarseness on growth performance, GIT development and functionality. Diarrhoea incidence was higher (p < 0.05) for CERfSBMf during the 2 weeks following the E. coli challenge compared to the other diets. Daily gain and feed intake during this period were higher (p < 0.05) for pigs fed CERc compared to CERf. Empty stomach weight tended to be greater by 8% (p = 0.09) for CERc compared to CERf. Gastric protein (p = 0.05) and starch (p = 0.04) disappearances were greater for SBMf compared to SBMc. Thus, CERcSBMf resulted in the best growth performance and lowest diarrhoea incidence during the 2 weeks following the E. coli challenge, which may be explained by changes in stomach functionality but not by changes in other parts of the GIT. [ABSTRACT FROM AUTHOR]

The purpose of the work is to present issues related to the influence of surface treatment on the strength of adhesive joints of C45 steel sheets by grinding based on experimental research. These issues were related to determining the impact of the gradation and type of abrasive material on the strength of adhesive joints of the steel sheets. The grinding was carried out manually using an angle grinder with a disc diameter of 125 mm and a rotational speed of 11.060 min-1, using abrasive materials with grains made of: ceramics, zirconium and electro-corundum with a gradation of P40, and sandpaper with grains made of electro-corundum with various grain sizes with three gradations P40, P220, P400 (according to European FEPA standards). To make the adhesive joints of steel sheets, the epoxy adhesive was used, which contains an epoxy resin based on bisphenol A and a triethyleneteramine curing agent. A profilographometer from Hommel - Etamic was used to determine selected 2D and 3D surface roughness parameters, and the strength tests of the steel sheets adhesive joints were performed on a ZWICK/ROELL Z150 testing machine. The analysis of the tests showed a significant impact of the surface treatment method on the attained shear strength of the steel sheets adhesive joints. Comparing the samples prepared with electrocorundum of the variable gradation, the tests exhibited that the samples prepared with P40 paper had the highest roughness, while samples prepared with P400 paper had the highest shear strength. Roughness analysis indicated that in the comparison group of samples prepared with abrasives of the various abrasive materials, ceramics showed the highest roughness parameters and the shear strength of the adhesive joints after this treatment. [ABSTRACT FROM AUTHOR]

Nickel-based single-crystal superalloys are widely used in aerospace and industrial gas turbine blades due to their excellent material properties. However, these alloys are also known for their difficulty in machining due to their superior physical properties. To improve the surface quality of machined parts, this study investigates the effects of different grinding conditions (dry grinding, flood, minimum quantity lubrication (MQL)) on the surface morphology, grinding-induced damage layer, and subsurface microstructure of nickel-based single-crystal superalloys. The experiments show that under MQL conditions, as the wheel speed increases, the grinding marks become more uniform, surface micro-defects decrease, and surface quality improves. A comparison of the thickness of the grinding-induced damage layer (D) obtained from dry grinding, flood, and MQL reveals that MQL cooling is more effective in reducing the damage layer thickness of nickel-based single-crystal superalloys compared to flood cooling. With an increase in wheel speed from 15 to 35 m/s, the thickness of the subsurface damage layer reduced from 14.2 to 11.4 µm using emulsion cooling and from 12.8 to 9.1 µm using MQL cooling. Unlike dry grinding, the use of grinding fluid significantly impacts the subsurface microstructure of the alloy, effectively suppressing work hardening and reducing the thickness of the grinding-induced damage layer, thereby improving the surface quality. It has important theoretical and practical significance to improve the quality of grinding surface. [ABSTRACT FROM AUTHOR]

Riblet surface is a biomimetic surface that not only has the ability to reduce surface drag resistance of mechanical products in fluids, but also improves surface hydrophobicity. Therefore, studying its manufacturing technology has practical significance for solving its engineering applications. In order to grind the riblet surface on the cylindrical workpiece, an innovative hob-grinding strategy for reducing drag on cylindrical riblet surfaces using superhard grinding wheels with spiral abrasive pattern has been developed. To achieve this strategy, firstly, based on the analysis of the geometric topology features of the riblet surface, an engineered CBN grinding wheel with spiral arrangement of abrasive particles was designed based on the principle of gear hobbing machining. Then, the relationship between hob-grinding parameters and abrasive particle arrangement parameters on the parameters of the ground riblets was analyzed, and the process measures to increase the number of riblets on the cylindrical surface, the ratio of the height to spacing of riblets, and the impact on the surface geometry of the riblets were explored. Finally, the surface of the cylindrical riblet surface was ground through experiments, and under the conditions of this experiment, a riblet surface was obtained that its spacing, height, and ratio of the height-spacing were 93.85 µm, 14.65 µm, and 0.156, respectively. The research results indicate that using this strategy can grind the cylindrical riblet surface, and the proposed process strategy of increasing the number of riblets and the ratio of the height to spacing is feasible. [ABSTRACT FROM AUTHOR]

Carbon fiber reinforced thermoplastic (CFRTP) composites, known for their excellent mechanical properties and environmental sustainability, are highly sought‐after in aerospace, energy, and many other fields. Grinding could be used to realize the high‐accuracy and low‐damage machining of CFRTP components. However, due to the temperature sensitivity and water absorption of CFRTP, dry and flood lubrication grinding could cause thermal damage and hygrothermal aging, respectively. In addition, these methods could lead to dust and excessive cutting fluids harmful to the environment. Addressing these bottlenecks, this study is the first to propose using oil‐on‐water minimum quantity lubrication (OoW‐MQL) to grind CFRTP. Experiments including various lubricating conditions and grinding parameters were performed to investigate the grinding performance. Experimental results showed that OoW‐MQL with the oil–water proportion of 1:1 outperformed the other lubricating conditions, achieving the best surface quality with the lowest grinding forces and temperatures. The optimal oil–water proportion remained almost unchanged under different grinding parameters. Furthermore, importance analysis using the extreme gradient boosting (XGBoost) algorithm demonstrated that oil–water proportion was the most critical factor affecting surface roughness. This study proves the feasibility of OoW‐MQL and provides technical guidance for high‐quality grinding of CFRTP. Highlights: Oil‐on‐water minimum quantity lubrication (OoW‐MQL) was proposed to grind carbon fiber reinforced thermoplastic (CFRTP) composites.The experimental results of grinding forces, grinding temperatures, surface roughness and surface morphologies were analyzed, which proved that OoW‐MQL with oil–water proportion (1,1) had outstanding lubricating and cooling capability.The effect of grinding parameters on the optimal oil–water proportion was proved to be negligible through comparative tests under grinding parameters of high force and high temperature.Quantitative analysis using the extreme gradient boosting (XGBoost) algorithm identified the oil–water proportion as the most critical factor influencing surface roughness. [ABSTRACT FROM AUTHOR]

Introducing supplementary cementitious materials (SCM), e.g. fly ash, into cement composite results in ecological benefits. However, in the case of high amount of SCM used as a replacement of a part of cement, there are problems related to the development of the desired properties of the final composite. Such mixtures often require activation. In the first part of this series of publications, the results of chemical activation (using Na2SO4 and Ca(OH)2) of a mixture with a very high content of fly ash were discussed. The aim of this work was to investigate the influence of mechanical activation on hydration and microstructure of the binder composed of 80% of fly ash and 20% of cement. Mechanical activation was performed using a planetary ball mill. The following instrumental methods were used to investigate the activated fly ash-cement pastes: calorimetry, TG/DTG, FTIR spectroscopy, X-ray diffraction and scanning electron microscopy (SEM) coupled with EDS. It was shown that concomitant grinding of cement and fly ash is more effective compared to separate grinding. Mechanism of hydration/activation of such mixtures was discussed in detail. [ABSTRACT FROM AUTHOR]

This work uses an alumina wheel to investigate the eco-benign grinding for better surface integrity of Inconel 625 (IN 625). To achieve this, applying nanofluids (NFs) with the minimum quantity lubrication (MQL) principle has been adopted, aiming at eco-benign grinding practices. In this work, MoS 2 NFs, MWCNTs NFs and hybrid NFs (prepared by mixing MoS 2 and MWCNTs in a 1:1 ratio) prepared using deionized water as the base fluid have been used. An in-house developed MQL setup is used to aim the NFs inside the grinding zone. The first attempt has been made to grind IN 625 in these environments. The characterisation of NFs in terms of nanofluid stability, dynamic viscosity, thermal conductivity and surface wettability have been performed before their utilization in grinding operations. A comparison has been made between the results obtained from NFs grinding and those from dry and soluble oil-based MQL grinding. It has been found that hybrid NFs provide excellent lubrication and cooling effects, reducing grinding forces and improving surface quality. Moreover, scanning electron microscopy, energy-dispersive spectroscopy and X-ray photon spectroscopy are applied to investigate the ground surfaces under different grinding conditions. Also, residual stress (with the help of X-ray diffraction and electron backscattered diffraction) and microhardness have been determined to gain further insights into the grinding behaviour. The wheel and chip morphology analyses have been performed to support the findings. The findings from this investigation lead to the conclusion that applying nano-MQL improves grinding effectiveness and promotes cleaner grinding outcomes. Hybrid NFs prove especially effective, as the physical synergistic effect enhances and safeguards the surface integrity of the produced ground components. [Display omitted] • This work endorses the grindability improvement of Inconel 625 using nano-MQL. • Thermos-physical and tribological characteristics of developed nanofluids have been investigated. • Ground surfaces have been investigated using SEM, EDS, EBSD, XRD and microhardness techniques. • Findings have been corroborated with the wheel and chip morphology investigations. • Nano-MQL has shown promising results in grindability improvement of Inconel 625. [ABSTRACT FROM AUTHOR]

Copyright of Bearing is the property of Bearing Editorial Office 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.)

As an important component of mechanical transmission systems, internal splines are widely used in aerospace, industrial equipment, and other fields. However, internal splines are prone to deformation and shrinkage after heat treatment. At present, most internal splines with a pitch circle diameter greater than φ60 mm can be processed and shaped by ordinary corundum grinding wheels, but there is no effective processing method for the shaping of small- and medium-sized internal splines. This paper establishes a single abrasive material removal model; uses Abaqus to simulate three-body free grinding; and analyzes the effects of abrasive rotation angle, rotation speed, and grinding depth on material removal under different conditions. By comparing the tooth lead deviation and tooth direction deviation before and after internal spline grinding, the experimental results show that after ultrasonic vibration grinding, the internal spline tooth profile deviation is reduced by 41.9%, and the tooth direction deviation is reduced by 44.1%, which provides a new processing method for the deformation recovery of internal splines after heat treatment. [ABSTRACT FROM AUTHOR]

This paper investigates the potential of utilizing lubricated liquid carbon dioxide (LCO2 + MQL) as an alternative to conventional flood cooling in grinding operations. This approach could facilitate a transition towards fossil-free production, which is a significant challenge in industry. The alternative cooling–lubrication method relies on pre-mixed LCO2 and oil and a single-channel minimum quantity lubrication (MQL) delivery method, which has already demonstrated potential in machining with geometrically defined cutting edges. However, this method has been less explored in grinding. This study primarily evaluates the grindability of AISI 4140 steel, examining surface roughness, residual stresses, microhardness, grinding forces, and specific energy for different cooling–lubrication methods. The results indicate that LCO2 + MQL is capable of attaining surface roughness and microhardness that is comparable to that of conventional flood cooling, especially in the case of less aggressive, finish grinding. Nevertheless, the presence of higher tensile residual stresses in rough grinding suggests that the cooling capability may be insufficient. While the primary objective was to evaluate the technological viability of LCO2 + MQL in terms of grindability, a supplementary cost-effectiveness analysis (CEA) was also conducted to assess the economic feasibility of LCO2 + MQL in comparison to conventional flood cooling. The CEA showed that the costs of both the cooling–lubrication methods are very similar. In conclusion, this study offers insights into the technological and economic viability of LCO2 + MQL as a sustainable cooling–lubrication method for industrial grinding processes. [ABSTRACT FROM AUTHOR]

Polycrystalline diamond (PCD) is widely used for micro tools due to its high hardness and wear resistance. However, micro PCD tools face challenges in machining with high accuracy and efficiency. Therefore, electrical discharge machining grinding (EDM-grinding) composite machining was proposed. The effects of pulse discharge parameters on surface quality and microhole drilling performance of PCD tool were investigated. The results show that the surface roughness of helix flute and flank face of the fabricated PCD tool were 0.125 µm and 0.158 µm, respectively, as well as the inner wall roughness achieved 0.331 µm after drilling of microhole. The average current displayed a greater effect on the machining quality of PCD tools, with tool breakage in excessive average current. The preferred pulse discharge parameters were determined as an open-circuit voltage of 95 V, an average current of 1400 mA, a pulse width of 400 ns, and a pulse interval of 2000 ns. [ABSTRACT FROM AUTHOR]

V-active VCI® is a new class of corrosion inhibitors that utilize water as a propagation medium, enabling the development of cutting fluids with the addition of such inhibitor. Consequently, in addition to the necessary characteristics of a cutting fluid, they are capable of providing corrosion protection for both the metal workpiece and the machine, thereby avoiding the use of intermediate protective oils and subsequent degreasing, reducing the number of process steps, and lowering environmental impact. Additionally, the fluids in question pose no risks to humans and are biodegradable. Furthermore, the minimum quantity lubrication technique combined with wheel cleaning has been yielding excellent results for the grinding process. These results stem from various factors: quality of the produced workpiece, reduced environmental impact, preservation of operator health, and reduction of production costs. Therefore, in the present study, it was found that incorporating the benefits of V-active VCI® into the minimum quantity lubrication technique with cleaning brings excellent results for the grinding process. The performance of a base fluid and two fluids with corrosion inhibitor was compared in the grinding process of AISI 4340 steel with aluminum oxide wheel using the MQL technique (with and without wheel cleaning), comparing with the results obtained by the same fluids in conventional lubri-cooling. The tests evaluated: surface roughness, roundness errors, wheel diametral wear, power consumption, acoustic emission, cost analysis, and pollution. The results show that grinding using cutting fluids with volatile corrosion inhibitors was beneficial to the process for all three lubri-cooling conditions. [ABSTRACT FROM AUTHOR]

Surface finishing applications are still cumbersome manual tasks, therefore, robotization of the process is of great interest as it allows for automation and increased versatility. However, finishing processes are difficult to automate, mainly because of the variation in material removal. In particular, the variables involved undergo changes that modify the material removal rate. This paper proposes a methodology for modeling material removal automatically based on experimental data. The procedure consists of monitoring the material removed from the parts under study that are in an automated precision measuring system during the finishing process. Based on the experimental models, a control algorithm for continuous material removal is presented. It guarantees a homogeneous surface finish by varying the robot feed rate. Finally, the results of several experimental material removal models under different process conditions and the validation of the proposed control algorithm are presented. The results show that the proposed method achieves a substantial improvement in the homogeneity of the finish. [ABSTRACT FROM AUTHOR]

Copyright of Bearing is the property of Bearing Editorial Office 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.)

Grinding is one of the most complex techniques of removing material from parts by the countless number of hard and sharp abrasive grains. Grinding creates a substantial amount of heat, which causes surface or subsurface damage, thermal damage, change in the metallographic structure of the material surface. In order to lesson these phenomena, cutting fluids are frequently used in the grinding zone. Minimum Quantity Lubrication (MQL) was suggested as a cost-effective and environmentally friendly lubrication for reducing heat and the expenses of grinding fluid. Despite the fact that MQL plays a crucial role in increasing machining performance, reviews on its use in high-speed machining are conflicted. This review article examines some of the most frequent nanofluids used in MQL systems during grinding processes. Nanofluids in MQL technique are a cutting-edge and eco-friendly approach that substitutes both traditional MQL and flood coolant in the grinding process. The effects of nanofluids on workpiece surface roughness, tangential force, coefficient of friction, G-ratio, grinding specific energy, wheel wear, grinding temperature, workpiece hardness and residual stress are thoroughly discussed and the findings were compared. After reading this review article, one may quickly gain an overview of existing research in the fields of nanofluids. Finally, this study looks at the thermo-physical characteristics of different nanofluids such as contact angle, thermal conductivity, and viscosity. [ABSTRACT FROM AUTHOR]

Nickel-based superalloy grinding, as well as selecting the appropriate operational parameters, is one of the major challenges in machining engineering. The conducted research consists of two sections. The first section presents a systematic experimentation, which has been carried out to qualitatively and quantitatively investigate nickel-based superalloy grinding. Vitrified CBN grinding wheels, along with a rotary diamond cup dresser, were utilised to conduct the experiments with the workpiece of Inconel 738. Specific grinding energy, G-ratio and surface roughness were indicated as three major machining outputs, while the inputs were the dressing conditioning and grinding parameters. In the following, the effects of different operational parameters were relatively ranked according to their weighted impact on the grinding performance using hybrid multi-attribute decision-making (MADM) methods. For this purpose, a combination of three techniques: Analytic Hierarchy Process (AHP), Entropy and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was utilised to select the most appropriate grinding conditions, while considering the conflicting effect of the different dressing and grinding parameters. The results indicate that specific energy can be an important criterion for evaluating the process efficiency. The changes in G-ratio and surface roughness have the same trends, as opposed to specific grinding energy mutation. The grinding parameters are summarised in equivalent chip thickness. Our findings show that dresser cross feed rate, along with equivalent chip thickness, has the greatest impact on the grinding process efficiency. [ABSTRACT FROM AUTHOR]

With the continuous development of machining methods, it is necessary to explore grinding and measuring methods to ensure the fatigue life and improved accuracy of bearings. In this study, a single-sensor three-point (SSTP) on-line outer-diameter measuring instrument was designed to ensure the consistency of the machining accuracy of precision bearing rings. Moreover, the mathematical model of the measuring instrument was established. The roundness and cylindricity error measurements of the ring outer diameter of precision bearings A and B form different manufacturers of countries were compared and analyzed. In addition, the accuracy measurement of the experimental grinder was investigated through multidimensional experiments. The results demonstrated a measuring and repetitive accuracy of ±1.25 and 1 μm, respectively. The measuring results conformed to the 3 б principle. The measured outer diameter was within the actual value of the workpiece outer diameter ±3 б, and the accuracy was over 99.73%. The instrument did only measure the outer diameter, but also measured the waviness error. The outer diameter and rotating speed did not clearly affect the measuring accuracy. The use of a lubricating fluid reduced the contact resistance of the on-line measuring instrument and significantly reduced the absolute error of outer diameter measurement, which is beneficial in improving the outer diameter measurement accuracy of the instrument. [ABSTRACT FROM AUTHOR]

Ceramic matrix composites (CMCs) are highly promising materials for the next generation of aero-engines. However, machining of CMCs suffers from low efficiency and poor surface finish, which presents an obstacle to their wider application. To overcome these problems, this study investigates high-efficiency deep grinding of CMCs, focusing on the effects of grinding depth. The results show that both the surface roughness and the depth of subsurface damage (SSD) are insensitive to grinding depth. The material removal rate can be increased sixfold by increasing the grinding depth, while the surface roughness and SSD depth increase by only about 10%. Moreover, it is found that the behavior of material removal is strongly dependent on grinding depth. As the grinding depth is increased, fibers are removed in smaller sizes, with the fiber length in chips being reduced by about 34%. However, too large a grinding depth will result in blockage by chip powder, which leads to a dramatic increase in the ratio of tangential to normal grinding forces. This study demonstrates that increasing the depth of cut is an effective approach to improve the machining efficiency of CMCs, while maintaining a good surface finish. It provides the basis for the further development of high-performance grinding methods for CMCs, which should facilitate their wider application. HIGHLIGHTS: • Both surface roughness and subsurface damage depth are found to be insensitive to the depth of cut. • The dependence of material removal behavior on grinding depth is revealed. • A technique for high-performance grinding of ceramic matrix composites is demonstrated. [ABSTRACT FROM AUTHOR]

This study aims to optimize the process of minimum quantity lubrication (MQL) grinding for Inconel 625 (IN 625) while enhancing its comprehensibility. The research employed experimental methods based on the Box-Behnken design to investigate critical parameters, including tangential force, surface roughness, specific energy, and apparent coefficient of friction. Further, machine learning techniques, specifically Random forest regression and Gaussian process regression (GPR), have been employed to build predictive models. These models have been assessed using metrics like R2, mean absolute error, and root mean square error. The results demonstrate that GPR outperforms other techniques in predicting the data accurately. Additionally, this study utilized multi-criteria decision-making techniques, namely TOPSIS and VIKOR, in conjunction with the entropy method to determine the optimal conditions for MQL grinding of IN 625. The optimized parameters for achieving low tangential force, high surface roughness, low specific energy, and low apparent coefficient of friction have been identified as a wheel speed of 1800 m/min, table speed of 9000 mm/min, and a depth of cut of 0.01 mm. Furthermore, a higher value of Ra (surface roughness) indicates the superior effectiveness of MQL grinding compared to dry grinding, as applying the MQL technique helps retain the sharpness of grit for a longer period of time. SEM image and EDS analysis of the ground surfaces confirm that better surface morphology has been obtained at optimized parameters of MQL grinding. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department 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.)

Objective. Currently, cement is crushed in mills to a specific surface area of 2500-3000 and 3500-4500 cm2/g or more. Further grinding of clinker sharply worsens the properties of the resulting product. The relevance of the topic is due to the increased interest in reducing material and energy costs in the process of clinker grinding. The purpose of the work is to study the effect of different assortment of grinding media and weighted average ball diameter on the particle size of the final product, performing particle size analysis by particle diffraction. Method. To obtain reliable experimental data, a specially developed model of the grinding unit was used. Analysis of particle size by diffraction or spatial distribution (scattering spectrum) of scattered light was carried out using a laser analyzer. Result. A research methodology has been developed that meets the modern capabilities of experimental technology. Experimental studies have been conducted on clinker grinding in a laboratory mill. The combined effect of different assortments of grinding bodies and the average weighted diameter of the ball on the particle size of the final product has been determined. Conclusion. Studies of the curves of the final product obtained using different weighted average ball diameters have shown that large impact energy is not required to grind small grains; the diameter of the grinding bodies should decrease as the grain size of the material decreases. Therefore, the balls must have a minimum diameter, but sufficient to destroy the particles of the material.

The purpose of the work is to present issues related to the influence of surface treatment on the strength of adhesive joints of C45 steel sheets by grinding based on experimental research. These issues were related to determining the impact of the gradation and type of abrasive material on the strength of adhesive joints of the steel sheets. The grinding was carried out manually using an angle grinder with a disc diameter of 125 mm and a rotational speed of 11,060 min-1, using abrasive materials with grains made of: ceramics, zirconium and electro-corundum with a gradation of P40, and sandpaper with grains made of electro-corundum with various grain sizes with three gradations P40, P220, P400 (according to European FEPA standards). To make the adhesive joints of steel sheets, the epoxy adhesive was used, which contains an epoxy resin based on bisphenol A and a triethyleneteramine curing agent. A profilographometer from Hommel - Etamic was used to determine selected 2D and 3D surface roughness parameters, and the strength tests of the steel sheets adhesive joints were performed on a ZWICK/ROELL Z150 testing machine. The analysis of the tests showed a significant impact of the surface treatment method on the attained shear strength of the steel sheets adhesive joints. Comparing the samples prepared with electrocorundum of the variable gradation, the tests exhibited that the samples prepared with P40 paper had the highest roughness, while samples prepared with P400 paper had the highest shear strength. Roughness analysis indicated that in the comparison group of samples prepared with abrasives of the various abrasive materials, ceramics showed the highest roughness parameters and the shear strength of the adhesive joints after this treatment.

Grinding is a manufacturing process that demands cutting fluids due to its great heat generation. However, those fluids are extremely harmful to human health and nature. The minimum quantity of lubrication (MQL) has been a studied alternative, but its application in grinding is still limited due to its low heat removal and wheel clogging. In this context, the present research investigated the performance of a wheel cleaning jet (WCJ) associated with the MQL (MQL + WCJ) at three flow rates in grinding of VP50IM steel with a black silicon carbide wheel, comparing the results with MQL and flood method. The evaluated output parameters were workpiece surface roughness, surface topography, roundness error, diametrical wheel wear, G ratio, grinding power, tangential cutting force, acoustic emission, grinding cost analyses, and CO2 pollution emission. The application of the wheel cleaning jet reduced up to 17% the surface roughness, 16% the roundness error, 18% the diametrical wheel wear, 17% the G ratio, 22% the grinding power, 23% the tangential cutting force, 20% the acoustic emission, 60% the manufacturing cost, and 68% the CO2 pollution emission. The application of WCJ improved the performance of the MQL technique and reinforced its potential to contribute to industrial-scale cleaner manufacturing. [ABSTRACT FROM AUTHOR]

Purpose – This paper is supposed to provide a critical review of current research progress on thermal management in grinding of superalloys, and future directions and challenges. By understanding the current progress and identifying the developing directions, thermal management can be achieved in the grinding of superalloys to significantly improve the grinding quality and efficiency. Design/methodology/approach – The relevant literature is collected from Web of Science, Scopus, CNKI, Google scholar, etc. A total of 185 literature is analyzed, and the findings in the literature are systematically summarized. In this case, the current development and future trends of thermal management in grinding of superalloys can be concluded. Findings – The recent developments in grinding superalloys, demands, challenges and solutions are analyzed. The theoretical basis of thermal management in grinding, the grinding heat partition analysis, is also summarized. The novel methods and technologies for thermal management are developed and reviewed, i.e. new grinding technologies and parameter optimization, super abrasive grinding wheel technologies, improved lubrication, highly efficient coolant delivery and enhanced heat transfer by passive thermal devices. Finally, the future trends and challenges are identified. Originality/value – Superalloys have excellent physical and mechanical properties, e.g. high thermal stability, and good high-temperature strength. The superalloys have been broadly applied in the aerospace, energy and automobile industries. Grinding is one of the most important precision machining technologies for superalloy parts. Owing to the mechanical and physical properties of superalloys, during grinding processes, forces are large and a massive heat is generated. Consequently, the improvement of grinding quality and efficiency is limited. It is important to conduct thermal management in the grinding of superalloys to decrease grinding forces and heat generation. The grinding heat is also dissipated in time by enhanced heat transfer methods. Therefore, it is necessary and valuable to holistically review the current situation of thermal management in grinding of superalloys and also provide the development trends and challenges.

Abstract The surface morphology and roughness of a workpiece are crucial parameters in grinding processes. Accurate prediction of these parameters is essential for maintaining the workpiece’s surface integrity. However, the randomness of abrasive grain shapes and workpiece surface formation behaviors poses significant challenges, and accuracy in current physical mechanism-based predictive models is needed. To address this problem, by using the random plane method and accounting for the random morphology and distribution of abrasive grains, this paper proposes a novel method to model CBN grinding wheels and predict workpiece surface roughness. First, a kinematic model of a single abrasive grain is developed to accurately capture the three-dimensional morphology of the grinding wheel. Next, by formulating an elastic deformation and formation model of the workpiece surface based on Hertz theory, the variation in grinding arc length at different grinding depths is revealed. Subsequently, a predictive model for the surface morphology of the workpiece ground by a single abrasive grain is devised. This model integrates the normal distribution model of abrasive grain size and the spatial distribution model of abrasive grain positions, to elucidate how the circumferential and axial distribution of abrasive grains influences workpiece surface formation. Lastly, by integrating the dynamic effective abrasive grain model, a predictive model for the surface morphology and roughness of the grinding wheel is established. To examine the impact of changing the grit size of the grinding wheel and grinding depth on workpiece surface roughness, and to validate the accuracy of the model, experiments are conducted. Results indicate that the predicted three-dimensional morphology of the grinding wheel and workpiece surfaces closely matches the actual grinding wheel and ground workpiece surfaces, with surface roughness prediction deviations as small as 2.3%.

Abstract Incorporating automation into wind turbine blade manufacturing is important for reducing costs to meet current offshore wind energy production goals in the United States. This work proposes a process for automating three operations in wind blade manufacturing: trimming to remove flashing left over after bonding two blade skins together, grinding to produce a desired leading‐edge shape, and sanding to prepare the blade for bonding overlamination or adding paint to the surface. The majority of this work focuses on the toolpath generation. The algorithms were tested on a 5‐m blade section, and the results were analyzed in terms of operation speed and accuracy. Finally, future work is discussed to improve the performance of the system.

Composite materials based on modified stems of Heracleum sosnowskyi (Sosnowsky's hogweed) and polyurethane binder are used for thermal insulation of building structures. The purpose of this study was to create a mathematical model for the optimization of composite compositions and the prediction of their properties. Numerical methods of mathematical statistics were used and nomogram plots were obtained. It was possible to select optimal compositions for the given characteristics of composites based on modified stems of H. sosnowskyi and polyurethane binder and predict the thermophysical properties of composites by knowing their composition. To produce thermal insulation boards with a thermal conductivity coefficient of 0.05 W/(m°C) it was necessary to use particles of H. sosnowskyi with a size of approximately 5 mm. The ratio of plant raw material and polyurethane binder was approximately 3:1 by weight. The bending strength of the thermal insulation boards was 1.56 MPa, and the compressive strength was 0.27 MPa.

The use of dry methods of processing and beneficiation of mineral raw materials is one of the promising areas, as this approach to concentrate production is less energy-consuming, less labor-intensive, and economically beneficial. The paper presents experimental studies on preliminary dry separation of Arkachan deposit ores to determine the quality of beneficiation of the separation products. The studies on dressability were carried out on pilot plants for dry ore processing and beneficiation: combined impact crusher DKD-300, centrifugal mill TsMVU-800, pneumatic separator POS-2000. Processing of the obtained separation products by pneumatic separation and screening according to the sequential flow chart of crushing and grinding was carried out in laboratory conditions at a gravity concentration table SKO-0.5. The GRG test was performed at an ITOMAK-0.1 centrifugal concentrator using a sequential grinding circuit. The GRG test showed that for more efficient gravity separation of gold, up to total gold recovery of 73.91%, the degree of grinding up to 80% passing 0.071 mm was required, allowing obtaining a gravity concentrate graded at 70.28 g/t gold.

Due to the limitation of the supersonic flame spraying process method，the axle sprayed with tungsten carbide must ensure the surface roughness and dimensional accuracy through the grinding process，but the weak machining rigidity of the axle and the high wear resistance of the coating lead to the phenomenon of making the cutting tool and shaking the cutting tool in the grinding process，resulting in the unqualified grinding quality of the parts. Firstly，the influence of four fine grinding process parameters on the grinding surface roughness is studied by orthogonal experimental method. Then，the influence of clamping tools and grinding strategies on the cylindricity of parts is studied. Finally，the outer dimensions of the individual sections of the 15 axles are machined and collected and their process capability indices are calculated. The results show that the surface of the part with roughness of Ra0.4 can be obtained by selecting high grinding wheel linear velocity，small depth of cut and moderate grinding wheel axial feed rate and workpiece linear velocity，increasing the clamping length and rigidity of the clamping tool，and adopting the strategy of "coarse grinding-fine grinding-smooth grinding" to ensure that the cylindricity of the outer circle of the part is not more than 0.01 mm. The axle process capability index is not less than 1.33，and the entire grinding process is reliable and stable.

Abstract This study examined the impact of acid hydrolysis, tempo oxidation, and mechanical grinding on the physical, thermal, and structural properties of α-chitin nanocrystals and nanofibers. The manufacturing methods could influence the diameter, functional groups, and crystal patterns of the resulting nanoparticles. Analysis of the DLS results revealed that the size of acidic nanocrystals were smaller and showed improved dispersibility. The XRD patterns indicated that the chemical and mechanical treatments did not alter the crystalline arrangement of the α-chitin. FT-IR spectra analysis revealed that the chemical and mechanical methods did not affect the functional groups of the nanoparticles. DSC results showed that the nanoparticles had good thermal stability up to 400 °C, and it was found that the nanofibers had better thermal resistance due to their longer length. In the FE-SEM images, the nanoparticles were observed as fiber mats with a length of more than 100 nm. It was also found that the diameter of the nanoparticles was less than 100 nm.

This research is based on the modeling, internal structure analysis, and automation of a cassava grinding machine. For the design, the single-cylinder grinder was chosen due to its advantages, notably simplicity and versatility. The grinding method used in this type of grinder is compression. The mechanical design and simulation software first allowed for the design of the grinder and then for performing static analyses under three loads (P1 = 10000N, P2 = 15000N, and P3 = 20000N). The results of these tests led to the selection of P3 = 20000N as the straightening load, with a maximum stress value in the static analysis of 88,18 MPa and a maximum deformation of 0,000358 under the force of load P3. Additionally, the frequency analysis distinguished five resonance modes. The results for each mode concluded that no resonance would affect the machine, thus ensuring stable operation. Furthermore, fatigue, frequency, and safety factor studies showed that the machine could withstand a load of m3 = 2000 kg without damage, with a service life of 1e+09 cycles. Considering the total number of life cycles, which is 1e+09 cycles, this means that the machine will have a service life of 347000 years, with a total grinding output of 2e+12 kg of cassava and 5840000 kg per year. The factor of safety is FoS = 1,78, indicating a sufficient margin for safe operating conditions. The automation of the grinder was carried out using a GRAFCET model and a sophisticated human-machine interface (HMI), providing an additional safety point for the machine and allowing the operator to monitor the operation via a simple graphical interface. This automation enables continuous operation with minimal human intervention, thereby improving the efficiency and safety of the cassava grinding process. [ABSTRACT FROM AUTHOR]

The surface morphology and roughness of a workpiece are crucial parameters in grinding processes. Accurate prediction of these parameters is essential for maintaining the workpiece's surface integrity. However, the randomness of abrasive grain shapes and workpiece surface formation behaviors poses significant challenges, and accuracy in current physical mechanism-based predictive models is needed. To address this problem, by using the random plane method and accounting for the random morphology and distribution of abrasive grains, this paper proposes a novel method to model CBN grinding wheels and predict workpiece surface roughness. First, a kinematic model of a single abrasive grain is developed to accurately capture the three-dimensional morphology of the grinding wheel. Next, by formulating an elastic deformation and formation model of the workpiece surface based on Hertz theory, the variation in grinding arc length at different grinding depths is revealed. Subsequently, a predictive model for the surface morphology of the workpiece ground by a single abrasive grain is devised. This model integrates the normal distribution model of abrasive grain size and the spatial distribution model of abrasive grain positions, to elucidate how the circumferential and axial distribution of abrasive grains influences workpiece surface formation. Lastly, by integrating the dynamic effective abrasive grain model, a predictive model for the surface morphology and roughness of the grinding wheel is established. To examine the impact of changing the grit size of the grinding wheel and grinding depth on workpiece surface roughness, and to validate the accuracy of the model, experiments are conducted. Results indicate that the predicted three-dimensional morphology of the grinding wheel and workpiece surfaces closely matches the actual grinding wheel and ground workpiece surfaces, with surface roughness prediction deviations as small as 2.3%. [ABSTRACT FROM AUTHOR]

The current study evaluated the effect of powder fractionation based on particle size on the chemical composition of macronutrients such as proteins and sugars, on the phytochemical properties (total content of polyphenolic compounds, vitamin C, and antioxidant activity), on preservation capacity (water activity), powder functional properties (water absorption capacity and water solubility index), and physicochemical properties (particle size distribution and moisture content) of blackthorn berry (Prunus spinosa) powders. The fruits were separated from the plant material and seeds, dried, and then ground using an universal mill for dry materials. Eight fractions were obtained after sieving on sieves with different mesh sizes, such as 1 mm, 0.8 mm, 0.630 mm, 0.450 mm, 0.315 mm, 0.200 mm, and 0.125 mm. The grinding/sieving procedure was effective in separating Prunus spinosa powder into sufficiently different size classes. The maximal moisture content and water activity were 5.61% and 0.250, respectively, showed good preservation from a microbiological point of view, and ensured the prevention of oxidation of biologically active compounds of blackthorn berry powders. For samples with reduced particle sizes, the powder functional properties were greatly improved. The total phenolic content, carbohydrates, and antioxidant activity showed significantly different values for some particle size classes compared to the un-sieved sample. A considerable content of vitamin C was presented in the fraction with large particle sizes, precisely because they did not undergo intense degradation processes. Therefore, the technique of grinding and successive sieving proved effective in enhancing the physicochemical and functional characteristics of powdered blackthorn berries, particularly for smaller particles. [ABSTRACT FROM AUTHOR]

A new method for the sustainable synthesis of various functionalized biaryls through the solid‐state Suzuki–Miyaura cross‐coupling reaction has been developed. This solid‐state protocol employs a palladium catalyst anchored on diazabicyclo[2.2.2]octane silica ferrite composite (Pd‐DDIL@Fe3O4‐SiO2). The catalyst has been fully characterized using multiple techniques such as FTIR, XRD, FESEM, EDS, elemental mapping, HR‐TEM, XPS, BET, TGA‐DTA, and VSM. The Pd‐DDIL@Fe3O4‐SiO2 catalyst has a surface area of 60.17 m2 g−1 and a magnetization saturation of 40.95 emu g−1. The TEM analysis revealed the rough spherical morphology of PdNPs having a particle size of 7 nm. The catalyst has excellent activity and selectivity towards the synthesis of both symmetrical and unsymmetrical biaryls under solid‐state, solvent‐free grinding conditions using a mortar and pestle. This method is eco‐friendly, as it is performed at room temperature without any solvents. The method employs the excellent yield of the products (90–96%) in a short reaction time (3–20 min). The desired products are isolated easily without any use of organic solvents. The catalyst can be easily separated using an external magnet and reused at least six times with an admirable change in yield. Additionally, the catalytic system has been shown to have a high TON and TOF, thus confirming its sustainability. [ABSTRACT FROM AUTHOR]

Green synthesis using L-proline as an organocatalyst is crucial due to its reusability, mild conditions, clean reactions, easy workup, high purity, short reaction times, and high yields. However, existing methods often involve harsh conditions and longer reaction times. In this study, 2-cyano-N'-(2-cyanoacetyl)acetohydrazide (3) was prepared and condensed with various benzaldehyde derivatives to yield 2-cyano-N'-(2-cyano-3-phenylacryloyl)-3-phenylacrylohydrazide derivatives (5a–e, 7a,b) using a grinding technique with moist L-proline. Additionally, three 2-cyano-N'-(2-cyano-3-heterylbut-2-enoyl)-3-heterylbut-2-enehydrazides (9, 11, 13) were synthesized by condensing compound 3 with respective (heteraryl)ketones (8, 10, 12) following the same method. The synthesized compounds were characterized using IR, NMR, and MS spectroscopy. L-proline's reusability was confirmed for up to four cycles without significant yield loss, showcasing the protocol's efficiency and sustainability. The new compounds were screened for anticancer activities against the HCT-116 colon carcinoma cell line using the MTT assay. Molecular docking studies revealed the binding conformations of the most potent compounds to the target protein (PDB ID 6MTU), correlating well with in vitro results. In silico ADMET analysis indicated favorable pharmacokinetic properties, highlighting these novel compounds as promising targeted anti-colon cancer agents. [ABSTRACT FROM AUTHOR]

The particle shape in mineral processing is a function of the comminution mechanism. In this study, the effect of the concentrate particle shape, obtained from the wet ball milling and the low-intensity magnetic separator on magnetite ore is investigated by the fractal geometry approach. The particle shape is described by the fractal dimension, calculated by the divider method. The variable parameters of grinding time, loading ratio, and solid weight percentage were studied here. The fractal dimensions of the particles are obtained between 1.12 and 1.42. When the grinding time is increased from 45 to 65 minutes, the fractal dimension and product grades are increased from 1.19 to 1.42 and from 65.61 to 67.70%, respectively. By increasing the loading ratio from 14% to 22%, the fractal dimension and the product's grades are increased from 1.17 to 1.38 and from 64.80 to 66.68%, respectively. By increasing the solid weight percentage from 35 to 55%, the fractal dimension and product grades are decreased from 1.32 to 1.12 and from 65.51 to 64.65%, respectively. The results show that the particle shape has a significant effect on the performance of the magnetic separator. It is the findings indicate a direct relationship between the particle fractal dimension and the grade of magnetic separation products. [ABSTRACT FROM AUTHOR]

This paper presents a method of calculating and correcting grinding face gears on an internal gear grinding machine. The generating principle of face gears is studied, and the feasibility of grinding motion on an internal gear grinding machine is analyzed. Then, the motions that need to be followed for grinding are analyzed based on the gear machine tool structure. Four main error sources causing tooth surface deviation in the grinding movements are proposed. The mathematical modeling of the grinding of face gears containing proposed error sources on an internal gear grinding machine is accurately established. The influence of the error sources on the topological deviations of the tooth surface is explored. A sensitivity matrix is established for the influence of various error factors on the tooth surface deviations. The correction values of each error factor are obtained in the case of existing tooth surface deviations. Finally, a virtual machining experiment is conducted, which proves the accuracy of the proposed method for characterizing grinding and realizing corrections. [ABSTRACT FROM AUTHOR]

Incorporating automation into wind turbine blade manufacturing is important for reducing costs to meet current offshore wind energy production goals in the United States. This work proposes a process for automating three operations in wind blade manufacturing: trimming to remove flashing left over after bonding two blade skins together, grinding to produce a desired leading‐edge shape, and sanding to prepare the blade for bonding overlamination or adding paint to the surface. The majority of this work focuses on the toolpath generation. The algorithms were tested on a 5‐m blade section, and the results were analyzed in terms of operation speed and accuracy. Finally, future work is discussed to improve the performance of the system. [ABSTRACT FROM AUTHOR]

Copyright of Nonferrous Metals (Mineral Processing Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group 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.)

In the machining process known as grinding, fluid is applied to regulate the temperature of the workpiece and reduce the risk of expensive thermal damage. The factors that influence the transport of this grinding fluid are not well understood; however, it is important to gain understanding in order to try to avoid the unnecessary cost incurred from its inefficient application. In this work, we use the method of matched asymptotic expansions to derive the multiscale system of equations that governs the flow. Under the lubrication approximation, we show that it is possible to calculate the flow rate through the grinding zone without having to solve for the flow far from the grinding zone. Additional empirically determined boundary conditions do not need to be imposed. With this lubrication model, we quantify the effect of experimental parameters on the flow field in the grinding zone and study how the flow regime responds to changes in these parameters. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) 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.)

Composite materials based on modified stems of Heracleum sosnowskyi (Sosnowsky's hogweed) and polyurethane binder are used for thermal insulation of building structures. The purpose of this study was to create a mathematical model for the optimization of composite compositions and the prediction of their properties. Numerical methods of mathematical statistics were used and nomogram plots were obtained. It was possible to select optimal compositions for the given characteristics of composites based on modified stems of H. sosnowskyi and polyurethane binder and predict the thermophysical properties of composites by knowing their composition. To produce thermal insulation boards with a thermal conductivity coefficient of 0.05 W/(m°C) it was necessary to use particles of H. sosnowskyi with a size of approximately 5 mm. The ratio of plant raw material and polyurethane binder was approximately 3:1 by weight. The bending strength of the thermal insulation boards was 1.56 MPa, and the compressive strength was 0.27 MPa. [ABSTRACT FROM AUTHOR]

Grinding is an indispensable process in many industrial plants. Nonetheless, the ground products may pass through the surface and/or undergo structural changes that may affect subsequent processes. In this study, the changes in the oil shale surface during its dry grinding in a ball mill were followed by Fourier-transform infrared (FTIR) analysis under different grinding conditions such as grinding time, ball type (i.e. ceramic or steel), and number of balls. Moreover, the generated heat limits during grinding were revealed by correlating the change in surface function groups of the ground products with those of conventionally heated oil shale samples in a furnace. The results indicated that the more intense the grinding action, in terms of the number or size of grinding balls and the grinding time, the higher the variations in the ground products' FTIR spectra, indicating the higher the surface oxidation of oil shale. More interestingly, correlating the FTIR spectra of the heated samples with those of the ground products indicated that the temperature inside the mill does not exceed 150 °C. [ABSTRACT FROM AUTHOR]

The aim of this paper is to improve surface and subsurface workpiece properties in steel grinding by using nearly spherical ceramic grains in an elastic bond system. To characterize and evaluate the potential of this rather new tool concept, the resulting workpiece microtopography and the subsurface characteristics are analysed and cover residual stresses, micrographic cross sections, and EBSD images. The results include the effect of the different process parameters on increased mechanical process loads resulting in favorable surface properties characterized by mechanically induced plastic deformation and compressive residual stresses. With regard to the metallographic analyses, an increased grain refinement was identified in micrographs and EBSD images, which results from the changed chip generation mechanisms. The sum of the above effects shows an increase in the residual compressive stresses introduced into the workpiece. This reveals the potential of spherical ceramic grains in an elastic bonding system. [ABSTRACT FROM AUTHOR]

Grinding of workpieces from hardened steel, especially in case of safety relevant components, usually requires a reliable method for the detection of thermo-mechanical surface damages. Compared to the common post-process methods, in-process detection promises saving of detection time and, particularly, a fast reaction to negative influences on the surface integrity. The present work shows the suitability of magnetic Barkhausen noise (BN) for the in-process detection of thermo-mechanically influenced regions during an outer diameter cylindrical grinding process. Different from other non-destructive inspection methods, BN allows the detection of changes of the residual stress state even before the occurrence of visible tempering zones. However, in case of pronounced tempering or rehardening zones, a single BN value does not enable an unambiguous statement about the surface state. Therefore, additionally the specific grinding power P c " in dependence of the contact time Δt is considered, which allows to exclude grinding burn starting from light tempering zones. A particular focus of this study is the BN analysis during grinding with different types of grinding wheels. [ABSTRACT FROM AUTHOR]

Milling is traditionally the most used machining method when manufacturing complex gas turbine components. In particular those made from nickel-based superalloys. However, for larger free form surfaces, grinding may be an efficient alternative that could be used throughout the complete manufacturing route, from roughing to finishing. Hence, in this work the two processing methods has been compared in regard to surface integrity and productivity. Machining tests have been performed on case plates of heat-treated Alloy 718 using best practise setting for roughing and finishing with grinding and milling. The surface integrity of the work pieces was evaluated regarding surface topography, residual stresses, and deformation. This comparison showed that the main advantage with grinding is the ability to switch between roughing and finishing by just altering the depth of cut. Further, grinding offers lower surface roughness, compressive residual stresses, and significantly lower degree of deformation. From a productivity perspective, deep grinding may offer high material removal rates and ability to machine several work pieces in the same setup. However, grinding is limited to simpler free form geometries and may result in minor surface damages and abrasive surface residue. For selection of machining strategy, advantages and drawbacks shown in this work need to be considered for the application at hand in respect to productivity, surface integrity and requirements on fatigue life. [ABSTRACT FROM AUTHOR]

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

Copyright of Journal of Ceramics / Taoci Xuebao is the property of Journal of Ceramics Editorial Office 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.)