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The practical applications of zinc metal anode are restricted by detrimental dendrite growth and hydrogen evolution reaction (HER), especially at high current densities. Previous works have demonstrated that constructing Zn(002) texture could effectively suppress dendrite growth and HER. However, the surface grain distribution of commercial zinc metal remains indistinct. Herein, a simple mechanical grinding approach is demonstrated to construct (002)‐textured zinc metal anodes. After grinding, the (002) relative texture coefficient of commercial zinc metal increases from 10.58 to 42.28, indicating a significant more (002) planes exposure. As prepared (002)‐textured zinc anode exhibits a high critical current density of 141 mA cm−2 and stably cycles for over 1500 cycles at 50 mA cm−2 and 1 mAh cm−2. Benefiting from the stability and fast kinetics of this (002)‐textured zinc anode, the zinc‐ion capacitor achieves a power density of 8500 W kg−1 and long cycle over 10 000 cycles with Coulombic efficiency (CE) exceeding 99.9%. This work provides both fundamental and practical insights for dendrite‐free and HER‐suppressed zinc metal anodes and inspiring guidance for other metal batteries. [ABSTRACT FROM AUTHOR]

Aiming at the problem of fine particles entrainment in the underflow of hydrocyclone during the metal grinding classification process, a water-injection hydrocyclone was proposed to improve the classification efficiency. Through external injection of water on the wall surface of the cone section, the particles settling in the region were loosely graded so that the fine particles settled in the wall surface returned to the inner swirl again, thus reducing their entry into the underflow. Numerical simulation was used to explore the differences in the internal flow field characteristics and separation performance of the hydrocyclone after adding the water-injection structure. Then the industrial tests were conducted on the classification performance of the water-injection hydrocyclone. Numerical results showed that compared with the conventional hydrocyclone, the static pressure, tangential and axial velocity of the fluid inside the water-injection hydrocyclone increased, while the turbulence intensity decreased. The experimental results showed that with the increase of water-injection flow rate, the content of -74 µm particles in the underflow of water-injection hydrocyclone first decreased and then increased, and the comprehensive classification efficiency increased and then decreased accordingly. Compared with the conventional hydrocyclone, the content of -74 µm particles in the underflow of the water-injection hydrocyclone was reduced from 26.34% to 23.95%, and the comprehensive classification efficiency was increased from 69.22% to 73.03%, which mitigated the phenomenon of fine particles entrainment in the underflow. [ABSTRACT FROM AUTHOR]

The demand of hybrid-metal-matrix composites (HMMCs) is rising continuously in various industries such as aerospace, automobile and biomedical. Therefore, effective machining of HMMCs is essential for their productive utilisation. However, machining processes are usually not feasible for shaping this composite due to inherent properties of matrix and reinforcing material, and melting of reinforcement particles. In the present work, a hybrid Electro-Chemical Surface Grinding (ECSG) setup has been developed by combining the Electro-Chemical Machining and Mechanical Grinding action. The process applied on Al-SiC-Gr composite, which is a key member of HMMC family. It is a better alternative for many parts like piston and piston ring in automobile industries. Central composite design-based Response Surface Methodology has been used for experimental modelling, response prediction and optimisation. The effects of significant control factors such as applied voltage, electrolyte concentration, wheel speed, table speed and electrolyte flow rate on material removal rate (MRR) and surface roughness (SR) have been studied. The results revealed that electrolyte concentration and applied voltage are most significant factors for both MRR as well as SR. Genetic algorithm-based optimisation results confirm 45% and 38% improvements in MRR and surface finish. [ABSTRACT FROM AUTHOR]

In situ resource utilization is a necessary means to achieve sustainable development of human habitation on the Moon. Grinding processing enables the processing and application of abundant mineral resources on the Moon, allowing for the manufacturing of high-quality mechanical components and the restoration of component surfaces. The thermal transfer system of grinding becomes particularly complex under the influence of extreme conditions such as vacuum, low gravity, and significant temperature variations. This review examines the latest research and future prospects on grinding thermal behaviors under simulated vacuum conditions. First, the generation and propagation mechanisms of grinding heat are analyzed. Measurement methods for grinding temperature in extreme environments are summarized. Second, the heat transfer system framework under simulated vacuum conditions is constructed. A comparative analysis is conducted on the impacts of different heat source models, process parameters, and simulation methods. Third, the influencing factors of heat transfer behavior are summarized. Then, the framework for an efficient cooling system is constructed. Finally, the consequences of grinding-induced heat are summarized. This review provides essential technical means and guidance for the high-quality application of space resources and the development of human lunar exploration and migration technologies. [ABSTRACT FROM AUTHOR]

The reduction in friction is a desired property in many industries. Some of the applications include the movement of liquid or slurry through a pipeline in oil or mining, the grinding of one metal on another during fabrication, metal on paper in the making of nearly any paper product, to even something closer to home with the movement of a brush or comb through one's hair. Friction yields higher degrees of strain or stress on one or both of the substrates. This can be costly due to energy requirements, wear of equipment, or even breakage of the substrate. Even though the need exists in so many industries, the mechanisms of lubricity vary enough in each that there really is not a universal lubricity aid that can successfully be applied across the different industries. A family of novel lubricity aids based on alkyl polyglucosides have been synthesized and evaluated in the lab on both metal/metal friction reduction as well as comb/hair friction reduction. One of the modified alkyl polyglucosides has yielded excellent reduction in friction in both applications. [ABSTRACT FROM AUTHOR]

Study of complex machining behavior of metal matrix composites has always been a matter of investigation. The different mechanical, physical and thermal properties of matrix and reinforcement materials pose difficulties in machining by conventional or advanced processes. Recent research works show that although electrochemical machining (ECM) process can be used to machine MMCs, it leads to inferior surface quality and formation of oxide layer on the machined surface which restricts the application of ECM. This work investigates the machining performance of Al-SiC-Gr MMC using ECSG which is a hybrid variant of ECM. Artificial intelligence-based hybrid approach of ANN and GA has been applied to predict and optimize the surface roughness (SR), oxide layer thickness (OLT) and micro-crack width (MCW). The results show an overall improvement of 29% in multiple quality characteristics SR, OLT and MCW. The SEM images of machined surface also reveal the improvement in surface quality. [ABSTRACT FROM AUTHOR]

In the current study, the wear behavior of bronze-bonded grinding tools when grinding the titanium alloy Ti-6Al-4V was explored. In this process, oxidation plays a key role since both the bronze bond and the titanium workpiece chemically react with oxygen. The oxidation effect is intensified further due to increased temperatures during grinding and can cause tribo-oxidation. This wear effect can be reduced or even eliminated by grinding in an extreme high-vacuum (XHV) adequate atmosphere. This atmosphere is nearly oxygen-free and is generated using a silane-doped argon gas that chemically reacts with oxygen. This reaction is able to decrease the oxygen partial pressure (pO2 ≤ 10−12 mbar) down to an XHV-adequate atmosphere. The aim of this paper is to investigate the influence of oxygen in the atmosphere on the application and wear behavior during grinding and to demonstrate the potential of this novel approach. The results presented show that during grinding with cBN, the process forces are significantly influenced by the atmosphere. Depending on the process parameters, a reduction of up to 93% is thus possible. This force reduction correlates with radial tool wear. When grinding under oxygen-free conditions, it can be reduced by up to 64%. [ABSTRACT FROM AUTHOR]

Solid‐state fluorescent materials are in huge demand owing to their potential applications in sensors, imaging, and LEDs. The molecular aggregations in the solid state limit their usage in practical applications. Typically, J‐aggregates show enhanced emission, while H‐aggregates show quenching in the solid state. Few supramolecular approaches (like creating hydrogen bonds) were developed to disturb the π–π and other supramolecular interactions in solid‐state H‐aggregates. Herein, we are reporting a p‐toulenesulfonyl hydrazide derivative of tri(biphenyl‐4‐yl)amine (TBA‐THZ) in the solid state showed negligible emission while grinding with M+X− (M+=alkali and alkali earth metal) salts showed enhanced emission. Existing supramolecular interactions were disturbed by dipole‐ion interactions between S=O⋅⋅⋅M+. The micro/nanometer‐sized salt crystal particles serve as templates for the TBA‐THZ molecules, and in the broad sense, the salt crystal surfaces act as a "solid‐state solvent." The TBA‐THZ ground with various metal salts showed varied emission intensities; the BaCl2 ⋅ 2H2O salt ground sample exhibited the maximum emission intensity. The KPF6+18‐Crown‐6 sample showed 84 times enhanced emission than the pristine TBA‐THZ. The role of 18‐crown‐6 ether was observed as a donor type for K+ ions. The expected S=O⋅⋅⋅K+ dipole‐ion interactions were elucidated through FT‐IR and computational modelling. The slight change in emission wavelength to the higher side after grinding with metal salt indicates that dipole‐ion interactions might slightly modify the chromophore's electronic structure, encouraging radiative decay and higher emission intensity. In contrast, a similar molecule, TBA‐PH, with no sulfonyl functional group, was silent in emission intensity. The TBA‐PH solid has no significant emission even after grinding with metal salts. The emission capacity of the TBA‐THZ salt‐ground powder remained unchanged at higher temperatures and in a highly humid environment. The fluorescent active salt ground matrix of the TBA‐THZ responded admirably to HCl acid fumes and was regenerated upon exposure to ammonia vapours. [ABSTRACT FROM AUTHOR]

The work is aimed at the development of a new sintered aluminium alloy with a low temperature coefficient of linear expansion that opens fundamentally new opportunities for solving the modern needs of domestic machinebuilding and instrument-making enterprises in light materials with special physical properties. Phase composition, structure and properties of cast aluminium alloys Al-Si-Ni with different contents of silicon and nickel, as well as powders obtained by grinding rapidly-quenched metal ribbons of these alloys in a high-energy ball mill are studied using various methods of structural analysis. The obtained values of the coefficient of linear expansion of the studied alloys in the cast state are significantly lower than those of pure aluminium, and they amount to = (11-15) 10-6 K-1. The method of obtaining a powder of a rapidly-crystallized alloy by manufacturing a rapidly-quenched metal ribbons using melt spinning followed by its dispersion in a high-energy ball mill is proposed for the fabrication of finely-dispersed powder and subse- quent hot pressing. [ABSTRACT FROM AUTHOR]

Recycling waste from the production and consumption of heat-resistant alloys to return them to production is an urgent task due to the high cost of the components contained in these alloys. The kinetics and conditions of the acid leaching process of the grinding waste of a heat-resistant nickel alloy are studied depending on the composition of the acid solution (H2SO4, HCl, HNO3, and their mixtures) at room temperature to boiling point temperature and various acid concentrations (1.5 to 3.0 mol/L), ratios of waste to solution (1:10 to 3:10), fraction sizes (0.04–1 mm), and contact duration (1 to 120 h). The linearization of experimental data by the Gray–Weddington, Gistling–Brownstein, and Kazeev–Erofeev equations showed that the rate of the leaching process was influenced by both the chemical reactions between sulfuric acid and metals included in the grinding waste and the diffusion of reagents through the film of reaction products and undissolved impurities. Optimal conditions for acid dissolution of the grinding waste have been established to obtain the maximum degree of extraction of the main component of the alloy, nickel. The processing of powder particles with a size of less than 0.1 mm should be carried out in a solution of sulfuric acid with a concentration of 3.0 mol/L at a temperature of 100 °C for 6 h with a ratio of solid to liquid phases of 1:10. The reported results are very important for industry personnel to recover metals and for environmentalists to treat the alloy waste. [ABSTRACT FROM AUTHOR]

The phase and X-ray structure composition of the initial and target products of Ni-Mo ligature and its melting conditions are determined. The optimal values of the content of charge materials during the smelting of a nickelmolybdenum-containing ligature were determine: scale of the alloy 79NM 4.2 - 28 % wt., shavings of power grinding of metal products 79NM 3.8 - 56.1 % wt., calcite molybdenum concentrate KMo 20.5 - 12.5 % wt., technical nickel oxide 13.0 - 22.0 % wt., cyclone silicon dust 3.4 - 7.9 % wt., metallic manganese MR-1 1.0 - 4.7 % wt., soot TGM-33 1.5 - 4.0 % wt., aluminium AK-8 0.8 - 6.0 % wt. Regularities of influence of charge parameters on the content of leading elements of ligature and efficiency of smelting of precision alloys with use of ligature are established. According to the specified method, calculations of economic efficiency of Ni and Mo utilization from man-made wastes of different sources of formation are performed. In order to achieve the optimal properties of the target ligature, taking into account the complex effect of the composition of the ingredients of the charge on reducing the cost of redistribution of the ligature smelting used regression analysis. The developed mathematical model of Ni and Mo burn-up dependences using the ligature on the content of 8 components in the charge for its smelting was tested by the generalized method of least squares on the basis of industrial data. High technical and economic efficiency of use of new alloying and de-oxidizing material at smelting of precision alloys is established. [ABSTRACT FROM AUTHOR]

Thermo-deformation treatment refers to methods of strengthening during which strengthened layers with a nanocrystalline structure are formed in the surface layers by modifying the metal surface layer, which changes its phase and structural and chemical compositions, reduces grain size, and improves performance. Grinding of the metal structure was achieved by combining two methods simultaneously during this treatment: the action of a highly concentrated energy source on the surface layer and intense plastic deformation. The source of highly concentrated energy was generated in the contact zone of the tool-disc, which rotates at high speed during friction on the treated surface. Intense deformation was achieved due to the grooves on the tool's working surface. Dynamic analysis of the thermo-deformation treatment process of flat surfaces of machine parts and a calculation scheme of the surface grinder machine's elastic system, which is the three-mass model, were developed. When the groove width increased from 4 mm to 8 mm, the force amplitude in the contact zone increased from 10 N to 75 N. Accordingly, the thickness of the nanocrystalline layer increased from 190–220 μm to 250–260 μm, and its hardness increased from 9.3 GPa to 11.1 GPa. [ABSTRACT FROM AUTHOR]

Grinding iron ores in conventional ball mills involve a considerably high consumption of metallic media, resulting in high operating costs. In the case of compact itabirites, the high silica content increases such consumption, potentially exceeding the costs associated with electric power consumption in industrial operations. This paper presents research conducted to assess the use of compact itabirite samples obtained from an industrial crushing plant as grinding media to assist conventional ball grinding in the same installation. In this case, the mill charge included both coarse ore fragments and steel balls. Two ore samples were characterized, and bench-scale grinding tests were carried out in laboratory mills 30 and 58 cm in diameter. The results indicated that coarse compact itabirite ore (pebbles) can be used as grinding media. Grinding tests have shown that replacing 25% of the steel balls with pebbles offered promising results. Their use as mixed grinding media results in a relatively minor increase in power consumption and low pebble wear. [ABSTRACT FROM AUTHOR]

Since Takagi et al. first developed palladium-catalyzed cyanation in 1973, transition metal-catalyzed cyanation of aryl halides, using Pd, Ni and Cu, has attracted widespread interest. However, the reactions are all dependent on highly polar organic solvents and high temperatures. Herein, we have developed the first electromagnetic mill (EMM) promoted mechanochemical palladium-catalyzed solid state cyanation of aryl bromides using non-toxic K4[Fe(CN)6] without additional heating. This strategy features broad substrate scope, good functional group tolerance, liquid-assisted grinding, air and moisture insensitivity, no additional heating, and efficient gram-scale synthesis. The EMM conditions can improve the efficiency of the reaction by colliding better mixed solid reactants with ferromagnetic rods at high speed. This EMM system not only provides a simple method for the preparation of aromatic nitriles which have a wide industrial application prospect, but also affords a broad space for liquid-assisted grinding solid metal catalytic synthesis. [ABSTRACT FROM AUTHOR]

Since Takagi et al. first developed palladium-catalyzed cyanation in 1973, transition metal-catalyzed cyanation of aryl halides, using Pd, Ni and Cu, has attracted widespread interest. However, the reactions are all dependent on highly polar organic solvents and high temperatures. Herein, we have developed the first electromagnetic mill (EMM) promoted mechanochemical palladium-catalyzed solid state cyanation of aryl bromides using non-toxic K4[Fe(CN)6] without additional heating. This strategy features broad substrate scope, good functional group tolerance, liquid-assisted grinding, air and moisture insensitivity, no additional heating, and efficient gram-scale synthesis. The EMM conditions can improve the efficiency of the reaction by colliding better mixed solid reactants with ferromagnetic rods at high speed. This EMM system not only provides a simple method for the preparation of aromatic nitriles which have a wide industrial application prospect, but also affords a broad space for liquid-assisted grinding solid metal catalytic synthesis. [ABSTRACT FROM AUTHOR]

Microwave-induced electric discharge machining (MV-EDM) is an emerging machining method that can be applied to fine machining of metal materials. A feasibility analysis of the application of MV-EDM to sharpen diamond grinding tools was conducted in this study. A multiphysical simulation model for sharpening using MV-EDM was established, and MV-EDM sharpening experiments and measurements were performed to verify the accuracy of the simulation model. It was found that MV-EDM can effectively improve the protrusion height h p and does not result in severe graphitization of diamond grains under appropriate conditions. Under the conditions of a microwave power of 1 kW and a gap scale d of 0.1 mm, the h p of the diamond grain increased to 91 μm with a complete diamond crystal shape and slight graphitization. In addition, it was discovered that the gap scale d and initial protrusion height h 0 had a significant effect on the protrusion height h p and the graphitization of the diamond grains. After verification, the accuracy of the simulation model for calculating the protrusion height of diamond grains was controlled within a range of ±15 μm. The results of this study provide a theoretical basis for the industrial application of MV-EDM to sharpening. [ABSTRACT FROM AUTHOR]

This article discusses a case series of traumatic tattoos that mimic pigmented skin tumors on videodermoscopy. Traumatic tattooing occurs when dark pigments, such as metal or graphite, are accidentally implanted into the dermis, often as a result of accidents or explosions. The article presents four cases of male patients with posttraumatic tattoos that were initially mistaken for melanoma, blue nevus, or pigmented basal cell carcinoma. However, further investigation revealed that the lesions were caused by trauma. The article emphasizes the importance of considering a patient's history of accidents to prevent unnecessary invasive procedures. [Extracted from the article]

Grinding is the most common method of abrasive finishing. Still, the primary issue faced is heat generation due to high-speed material removal, which leads to thermal damage on the work surfaces and inferior surface finish. Therefore, coolant is supplied at the grinding zone to overcome the temperature rise. In the present work, pore aligned grinding wheel is designed for an adequate supply of coolants. The grinding performance was evaluated in EN 18 Steel workpiece through experiments formulated as per the L18 orthogonal array. Grey relational analysis combined with principal component analysis was utilized to minimize surface roughness (SR) and specific energy (SE) and to improve the material removal rate (MRR), grinding ratio (GR), and grinding efficiency (GE). The input parameters considered are different grades (J, K, L) of the wheel, grams per square meter (GSM) of the disc (190, 230, 260), and positions of disc insertion. For the said objective, optimal setting parameters were found at 230 GSM disc, wheel grade of "K," and disc position at the inner portion of the wheel. The position of a disc is the vital parameter that influences the objective function by 67.3%, disc insertion by 12.6%, and wheel grade by 10.2%. [ABSTRACT FROM AUTHOR]

Reciprocating machining was common in metal cutting such as grinding and planning, he smoothness of the machining processes directly affected the machining quality, energy efficiency and even the life of the machine tools. Firstly, the influences of reciprocating (stroke) motion speed planning on the smoothness of motion processes were explored, based on the analysis of the kinematics performance of common speed planning, according to the characteristics of grinding stroke motion, it was proposed to reduce the influences of soft impact on machined surface quality by changing the partial distribution of jerks, and two speed planning algorithms were designed based on jerk continuity. Then, the relationship between speed planning algorithm and grinding force smoothness, machining surface roughness and machining energy consumption were studied, the method of reducing energy consumption by changing the spatial distribution of acceleration was proposed. The experimental results show that the speed planning of reciprocating motions is related to the smoothness of grinding forces, the roughness of machined surfaces and the energy consumption of machining. By changing the partial distributions of jerk and acceleration, the smoothness of grinding forces and the quality of machined surfaces are improved, and the energy consumption of machining is reduced. The comprehensive performance of the proposed type II speed planning is superior to other planning. Compared with he trapezoidal speed planning, the cutting force fluctuation, machining surface roughness and motor riving energy consumption are significantly reduced. [ABSTRACT FROM AUTHOR]

• A 3DOF ultrasonic vibration tool holder was proposed for rotary ultrasonic machining. • Proposed tool holder achieve 1DOF, 2DOF and 3DOF vibration machining. • Structural optimization achieve multi-vibration integration and switching, high rotary speed practicality. • Machining effects of various vibration forms were compared. • Vibration mode affect the machining quality and tool life in grinding. • 2DOF elliptic vibration has better comprehensive machining performance. The vibration form of the tool has a significant impact on the machining effect in rotary ultrasonic machining. Compared with 1DOF rotary ultrasonic machining, multi-DOF rotary ultrasonic machining have comprehensive advantages in the machining performance. However, the current multi-DOF rotary ultrasonic machining faces the challenges of miniaturization, multi-DOF vibration integration and high rotary speed. Therefore, a 3DOF ultrasonic vibration tool holder with decoupled three-channel contactless energy transfer was proposed, which realize 1DOF, 2DOF and 3DOF rotary ultrasonic machining with the same resonant frequency and the vibration conversion functions at high rotation speed. Structure design, principle analysis and simulation verification was carried out to determine the structure size and material. Through manufacturing and testing of prototype, the results show that under the performance of high speed, high transfer efficiency with 93 % and low temperature rise. The prototype of 3DOF ultrasonic vibration tool holder can not only integrate six vibration forms with high amplitude, but also has the function of replacing the milling tool for metal and grinding tool for brittle materials. Finally, through machining experiments with different vibration forms, two kinds of elliptical vibration produce regular textures with different shapes in the Ti-6Al-4V milling. In Al2O3 grinding, the surface roughness is the lowest under 2DOF vertical elliptical vibration grinding. While the 2DOF horizontal elliptical vibration grinding significantly improves the chip removal and prolongs the tool life. These findings provide guidance for machining performance under various vibration mode. It was proved that this tool holder integrated and switch with multiple vibration modes is of great value for high efficiency and high-quality multi-procedure machining. [Display omitted] [ABSTRACT FROM AUTHOR]

The aim of the article is the determination of cutting temperature during flat grinding of the combined mould part which consists of metal polymer and metal as well as establishing the correct cutting conditions. This article is about the sequence of technology for obtaining a combined mould-forming part of the mould and the importance of using the correct processing modes. The problem relates to the absence of information about the combined cutting temperature and consists in using incorrect cutting conditions, which can lead to thermal destruction of its internal structure. At the second part of the article, it is given a theory for calculating the heat release during grinding.. Afterwards, the calculations of heating the surface of the part were made using finite element analysis in the ELCUT 6.1 program. The third part of the research is devoted to discussing the results and conducting an experiment which could confirm or refute the previously obtained theoretical results. The temperature in the cutting zone was estimated for the mould plate, which became a reason for choosing a certain range of cutting modes, allowing to obtain the required roughness of the clamping plane of the mould.. [ABSTRACT FROM AUTHOR]

To improve the safety of wet dust removal systems for processing magnesium-based alloys, a new method is proposed for preventing hydrogen generation. In this paper, hydrogen generation by Mg–Zn alloy dust was inhibited with six common metal corrosion inhibitors. The results showed that sodium dodecylbenzene sulfonate was the best hydrogen inhibitor, while CeCl 3 enhanced hydrogen precipitation. The film-forming stability of sodium dodecylbenzene sulfonate was tested with different contents, temperatures, Cl− concentrations and perturbation rates. The results showed that this inhibitor formed stable protective films on the surfaces of Mg–Zn alloy particles, and adsorption followed the Langmuir adsorption model. • Metal dust explosion risk in metal grinding workshop. • A new method of preventing hydrogen generation. • New applications of metal corrosion inhibitors. • Hydrogen inhibition of Mg–Zn alloy dust by SDBS. • Effects of different conditions on the stability of conversion film. [ABSTRACT FROM AUTHOR]

Based on the study of the chemical composition and analysis of the physicochemical properties of waste from a number of metallurgical enterprises in the Zaporizhzhya region, the possibility of using waste as charge materials for the production of magnesium-based alloys has been established. The possibility of using solid salt chlorinator melt (SCM) from ZTMC as a flux in the smelting of magnesium alloy instead of the flux VI-2 has been studied; its effect on the structure and mechanical properties of casting was investigated. The technological possibility of using these chloride wastes in the smelting of the ML5 alloy is shown. It was established that the use of SCM as a flux in the smelting of magnesium alloy contributes to the grinding of the structure and improvement of the mechanical properties of the metal of experimental smelting. The possibility of modification of foundry magnesium alloy with graphite powder (GP), which is the waste from JSC «Ukrgrafit», is investigated. It is shown that the optimal GP additive in the volume of 0.05...0.3 % contributes to the grinding of metal grain and increases its strength characteristics due to additional strengthening of both solid solution and eutectoid. It is established that carbon changes the parameters of eutectic transformation, as a result of which, with an increase in its concentration in the alloy, the volume of eutectoid of type δ+γ (Mg4Al3) decreases markedly. Testing the proposed waste for the smelting of the M5 alloy showed that no changes in melting technology are required while the environmental safety of the devised technological process meets the established standards; their quality was improved while increasing the strength limit by 25 %, and plasticity by 30 %. At the same time, the use of waste in the smelting of magnesium alloys can reduce costs in its production, and improve the environmental situation due to the fact that waste is not disposed of at landfills but reused in metallurgical industries [ABSTRACT FROM AUTHOR]

Ultrasonic vibration–assisted grinding (UVAG) shows excellent performance in the machining of difficult-to-cut materials. Grinding force is one of the key factors affecting the quality of the machined surface, which has been investigated both experimentally and theoretically. However, the research on the modeling of the grinding force of the separated ultrasonic vibration–assisted grinding of metal difficult to cut materials is not in-depth for this process. It is concluded through experimental analysis that 304 stainless steel is removed by plastic removal under the action of tangential ultrasonic vibration–assisted grinding (TUVAG), and it is removed by brittle removal under the action of radial ultrasonic vibration–assisted grinding (RUVAG). On this basis, two kinds of prediction models of grinding force for ultrasonic vibration–assisted grinding are established. In addition, the relationship between grinding force and experimental parameters (spindle speed, feed rate, grinding depth, ultrasonic amplitude) was also revealed through models. Finally, the theoretical models are verified by experiments. The experimental results are consistent well with the models predictions. Therefore, these two theoretical models can be used to predict the grinding force well. [ABSTRACT FROM AUTHOR]

The VP50IM steels were developed to manufacture molds for thermoplastics injection and dies for thermoplastics extrusion. This article compares the grinding of VP50IM steel with black silicon carbide grinding wheel using the flood method and the minimum quantity of lubricant system (MQL) using feed rates of 0.25, 0.50, and 0.75 mm/min. The output parameters analyzed were surface roughness (Ra), roundness error, diametrical wheel wear, tangential cutting force, metallography, microhardness, scanning electron microscopy (SEM), cost analysis, and CO2 emission. The results revealed that the conventional system, due to its higher lubri-refrigerant capacity, provided a better performance compared to the MQL system. Furthermore, the lower feed rates provided superior results than higher feed rates. On the other hand, the results related to the cost and pollution show a superiority of the MQL system due to the lower use of lubricants. In addition, a higher feed rate was a determining factor in achieving a reduction in pollution and process cost. [ABSTRACT FROM AUTHOR]

A tangential ultrasonic vibration-assisted gear grinding (TUVAGG) system was proposed in this paper to enhance the machining accuracy and performance of gears. Firstly, the longitudinal resonant vibration system of the TUVAGG was designed based on the non-resonant theory. The frequency equation and the displacement characteristics for the vibration system were obtained for the particular boundary conditions. Secondly, the vibration system composed of simplified disc and gear was simulated by the finite elements analysis method (FEM) and verified by the resonant measurement test. Finally, the vibration system effectiveness was verified through the ultrasonic vibration-assisted gear grinding test. The normal and tangential grinding forces in TUVAGG were lower by 7.4–28.2% and 8.9–18.9%, respectively, than conventional gear grinding (CGG). Besides, the grinding temperature and surface roughness in TUVAGG declined by 7.6–25.7% and 8.6–21.8% respectively compared with CGG, while the former tooth surface residual compressive stress and microhardness exceeded the latter ones by 13.2–29.3% and 8.9–12.7%. The non-resonant theory was suitable for the designation of longitudinal vibration system for TUVAGG, and also provided a novel process technology for gear machining. [ABSTRACT FROM AUTHOR]

Laser polishing efficiently reduces the surface roughness of die steel, but at the same time, residual tensile stress is induced on the surface, leading to crack initiation and propagation. The present study induces residual compressive stress on the laser-polished surface of Cr12 steel by laser shock peening. The surface residual stress of samples, which underwent different treatments, is measured and compared. The experimental results show that laser shock peening effectively eliminates the residual tensile stress generated by laser polishing. The compressive residual stresses of the laser-polished samples subjected to laser shock peening with 3, 6, and 9 J energies are 114.5, −138.5, and −209.5 MPa, respectively. Moreover, the surface roughness, microhardness, and microstructure evolution of the laser-polished surface with laser shock peening are investigated. [ABSTRACT FROM AUTHOR]

Schiff base was synthesized by mixing parabenzoquinone and glycine mechanochemically. Its corresponding complexes of Cu, Co and Mn were synthesized by grinding metal (II) carbonates. The synthesized compound were characterized by elemental analysis, infrared spectroscopy, melting/decomposition temperature determination and conductivity measurements. The infrared spectroscopic analysis of the ligand shows a peak at 1620cm-1 confirm the presence of azomethane while the shift to1602 cm-1, 1623.15cm-1,1635.69cm-1 in Mn, Cu, Co complexes respectively confirmed bond formation from azo-group to metal. The melting point temperature of the ligand at 128.20PC show that it is stable at low temperature while the decomposition temperature of Mn, Cu, Co complexes at 190°C, 188.4°C, 205°C shows that they are stable conductivity measurement shows that the complexes were found to be non-electrolytic as compared with the theoretical values. The ligand and its respective complexes showed antimicrobial activities against some bacteria and fungi at high concentrations (1000 pg/disc and 500 pg/disc) respectively while some showed no activity at all concentrations. However, Co complex shows significant activity against all the species at low concentration (250 p/disc). [ABSTRACT FROM AUTHOR]

The design and fabrication of nano-diamond (ND) bonded silicon carbide (SiC) composite material were conducted as an attempt to obtain better drilling performance of SiC abrasives. The ND/SiC composite abrasives were fabricated by mechanical bonding of the NDs on the surface of SiC abrasives with the use of dry particle composing machine together with amorphous silica as a bond material. A comparative study on drilling performance for carbon fiber-reinforced plastic (CFRP) laminates by the SiC abrasives and ND/SiC composite abrasives was performed with dual-axis grinding wheel system. Hole-qualities such as roundness and roughness were improved by using the ND/SiC composite abrasives. Enhanced drilling performance of the ND/SiC composite abrasives was also obtained in terms of feed rate dependence of the thrust force. The ND/SiC composite abrasives could make holes with lower thrust force at higher feed rate, compared with the SiC abrasives due to the enhanced self-dressing effect together with the original drilling performance of the ND abrasive as synergetic effect caused by interfacial design between the ND/SiC composite abrasives and metal matrix in the grinding wheels. These results indicate the new controlling method of holding force of abrasive grains in metal bonded grinding wheel. [ABSTRACT FROM AUTHOR]

The formation of tetra- n -butylammonium bromide (TBAB) hydrate from a TBAB aqueous solution tends to show a supercooling phenomenon, which is non-ideal for the practical use of TBAB hydrate. However, as reported in the literature, the products obtained from the use of metal electrodes for the application of an electric field can accelerate the nucleation of the hydrate. Herein, we investigated the role of metal particles (Ag, AgBr, Zn, and ZnO) and their mixed forms (Ag–AgBr and Zn–ZnO) on promoting the nucleation of TBAB semiclathrate hydrate. The nucleation-promoting effect was most significant for the mixed metal particles when prepared by simultaneous grinding of the metal particle components. The changes in the physicochemical properties of the mixed metal particles as a result of grinding were believed to accelerate the nucleation of TBAB hydrate. [ABSTRACT FROM AUTHOR]

Utilizing natural waste as carbon source to prepare porous carbon with ultrahigh surface area and developing a facile protocol to synthesize supported metal nanoparticles toward an efficient formic acid (FA) decomposition are vital but remains challenging. Here, discarded ginkgo leaves were utilized as carbon source to prepare ginkgo leaf-derived porous carbon (GLPC) with an ultrahigh surface area of 3851 m2/g. Based on the as-prepared nitrogen-doped GLPC (N-GLPC) after "soft" nitriding, a facile solid-state reduction strategy with mortar-pestle grinding and without the use of any organic solvent and stabilizing ligand was developed to synthesize ultrafine and well-distributed Pd nanoparticles (NPs) with a diameter of 2.7 ± 0.7 nm. The "soft" nitriding temperature and addition of base during preparation played vital roles in the activity of the fabricated catalysts. The Pd/N-GLPC-350 exhibited the highest catalytic activity toward decomposing FA, achieving a high turnover frequency of 2952 h−1 at 333 K. The Pd/N-GLPC-350 was quite stable and could be reused at least five times without evident activity loss. This study provides a facile solid-state reduction protocol with mortar-pestle grinding to synthesize metal NPs by using natural waste-derived porous carbon as support toward efficient FA decomposition. Image 1 • Ginkgo leaf-derived porous carbon (GLPC) with a large surface area was produced. • A "soft" nitriding strategy was developed to prepare N-GLPC-350 support. • Ultrafine Pd nanoparticles were prepared by a facile solid-state reduction method. • Pd/N-GLPC-350 showed the optimal catalytic activity for formic acid decomposition. [ABSTRACT FROM AUTHOR]

Compliant finishing (e.g. shape adaptive grinding) can routinely achieve nanoscale roughness on diverse metal and ceramic materials. However, when processing multiphase materials consisting of distinct phases with different mechanical properties, non-uniform material removal often occurs and the inherent mechanism remains unclear. Here, a deterministic and stochastic model to predict processed surface topography is derived from the different material removal behaviours across phases. Experimental topographies, profiles and roughness on three selected Si-SiC samples show high consistency with theoretical predictions. Both model and experiments indicate that improved and stable surface finish can be achieved on metal matrix composites with small grain size. [ABSTRACT FROM AUTHOR]