Combined Processing Methods Research Articles

ТЕХНОЛОГИЧЕСКИЕ ПАРАМЕТРЫ КОМБИНИРОВАННОГО МЕТОДА ЭЛЕКТРОФИЗИКОХИМИЧЕСКОЙ ОБРАБОТКИ МАТЕРИАЛОВ

This paper describes a combined material processing method using the principles of an electrochemical electroerosion treatment method. Mathematical calculations of processing modes are given, as well as graphs of the efficiency and accuracy of processing, depending on the materials used as a working medium.

A life cycle-based comparison study of sludge recycling technology incorporating subjective and objective evaluations

Inadequate land capacity and low sludge recycling rates have become a major global environmental challenge. Low organic sludge content and inadequate waste management policy mean that there is an urgent need to improve sludge solutions in China, which has the world's largest WWT capacity. Decision-makers face difficulties in selecting sustainable sludge-to-resource technologies given the existence of multiple social, environmental and economic objectives, and also in optimizing the allocation of sludge between different available technologies. In this paper we used a combined analytic hierarchic process (AHP) and entropy weight (EW) method to evaluate four recycling technologies: aerobic composting (AC), dry-incineration (DI), hydrothermal carbonization (HTC) and pyrolysis (PY), in terms of five economic, environmental and land resource indicators. The results showed that human toxicity was viewed as the most important indicator, while economic value of sludge product was the least important. HTC had the best overall performance of the evaluated technologies while PY was the least attractive. However, all four sludge recycling technologies showed greater potential for reducing carbon emissions and human toxicity than landfilling when sludge dewatering was included. Sensitivity analysis showed that adjustments to AHP weights only had a limited impact on the technical ranking. Finally, the result was further verified by a particle swarm optimization algorithm. Considering capacity constraints, the optimal proportion of the four technologies was found to be 44.9%, 42.7%, 0 and 12.4% for HTC, DI, PY and AC respectively. The paper demonstrates the effectiveness of combining subjective and objective methods to evaluate multiple indicators, providing decision-makers with a practical analysis framework for waste technology selection.

Control of the structure and mechanical properties of metastable β-titanium alloy VT47 by combined thermomechanical processing methods

Control of the structure and mechanical properties of metastable β-titanium alloy VT47 by combined thermomechanical processing methods

Machining damage in the fabrication of polycrystalline diamond micro end mill with laser and grinding combined processing method

The high hardness and wear resistance of polycrystalline diamond (PCD) micro tool make it widely used in precision machining of small parts of difficult-to-machine materials. The laser and grinding combined machining is an effective method to fabricate PCD micro tools, but the machining damage is difficult to control, which will reduce the cutting performance and tool life. Therefore, this paper aims to deeply study the damage forms and damage formation mechanisms during the fabrication process of PCD micro end mills, so as to improve the quality of the PCD micro mills. The laser and grinding combined machining experiments of PCD micro end mill are carried out, and the surface morphology characteristics and cutting edge of the mill are observed and analyzed. The influence of process parameters on the fabrication quality of PCD micro mill is investigated. The experimental results show that the high temperature of the laser is the main factor causing damage, which causes the melting and oxidation of the surface material, and further forms micro cracks, pits and oxidized attachments on the PCD mill. In addition, diamond phase transformation and excessive removal of cobalt-rich layer will also lead to graphitization and micro-grooves on the mill surface. For the grinding process, the cutting edge is fractured by the impact of the wheel, resulting in micro notches, micro pits and micro cracks. The intergranular crack expansion of PCD material and cleavage breakage of diamond particles are the main causes of micro cracks and micro pits on the mill surface. In addition, the chips will also scratch the tool surface to produce micro nicks and cause the chips coating on the rake face. The research results are helpful to further understand the damage mechanism of laser and grinding combined machining PCD mill, so as to improve the fabrication quality of micro tools.

Structure and properties of surface layer of TiNi alloy subjected to ion-plasma- and ultrasonic treatment

The paper presents the results of research on morphology, elemental composition, microhardness, corrosion properties of the surface layer of TiNi alloy subjected to ion-plasma (vacuum-arc method) deposition of TiN coating and ultrasonic treatment (UT) with different number of passes (n). The SEM method showed that ultrasonic treatment provides a significant reduction in the amount of the droplet phase on the TiN coating surface. The surface discontinuity of TiN coating at local points was observed with an increase in the number of passes during ultrasonic treatment. The effect of combined processing methods on the microhardness of TiNi sample was studied. It was shown that the synergistic effect can be observed for two hardening methods. The combined strengthening method increased the microhardness of TiNi alloy (1.6 GPa in the as-received state): due to the deposition of a TiN coating – up to 10.9 GPa, due to subsequently ultrasonic treatment – up to 14.5–18.4 GPa depending on the number of passes. For UT + TiN scheme, it was shown that the open circuit potential Ecorr was about –250 mV which is practically independent of the number of passes and determined by the potential value of TiN coating. For TiN + UT scheme, it was found that with an increase in the number of passes, the value of Ecorr shifts towards more negative values approaching the open circuit potential value of the TiNi sample in the as-received state (–350 mV). The analysis of Scanning Vibrating Electrode Technique (SVET) results showed high electrochemical compatibility of substrate (TiNi) and coating (TiN) materials in a chloride environment with minimal current density fluctuations for the samples subjected to UT + TiN and TiN + UT (n = 1). The proposed method for TiNi alloy treatment according to TiN + UT scheme (n = 1) promotes an improvement of surface morphology and corrosion resistance.

Analysis of combined processing method of phosphate minerals from the Kef Essenoun deposit

Currently, the processing of beige and black phosphates only concerns the main sub-layers, while the other sub-layers (lower and upper for beige phosphate and the upper for black phosphate) are considered waste rock and stored near the complex. Therefore, the object of this research is the use of mixtures of three beige phosphate sub-layers and two black phosphate sub-layers as a feed fraction for the calcination and reverses flotation processes. This research work aims to characterise and treat two types of phosphate: one beige with the sub-layers (main, lower and upper) and the other black with the sub-layers (main and upper) in order to have better recovery of P2O5. The working methodology consists of a series of sample preparation operations and characterization of the two types of beige and black phosphate. This characterization includes a petrographic study, a granulochemical analysis, an X-ray diffraction (XRD), a scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS), and an atomic adsorption spectrophotometry (SAA), an auto analyzer (AA), a Bernard calcimeter. These analyzes allow on the one hand to identify the mineral phases in quantitative and qualitative manner, and on the other hand to choose the process for treating phosphates from the Kef Essenoun–Tebessa deposit. The combined method of treatment by calcination followed by reverse flotation gave satisfactory results. The P2O5 content reaches 33.88 % for beige phosphate and 33.13 % for black phosphate. The stored waste rock represents a problem for the company; this waste rock contains fairly high levels of phosphate. The treatment of the mixture of the main sub-layers with these waste rocks makes it possible to obtain a better recovery of P2O5, a better economic profitability of the Djebel Onk mining complex and an environmental impact in the region.

MATHEMATICAL MODELING OF THE HOLLOW PROFILES FORMING PROCESS

Steel alloys containing manganese and boron are increasingly being used in mechanical engineering, including automotive and agricultural sectors. Products of critical application made from such steels, including hollow ones, have a high level of mechanical properties, surface hardness, and wear resistance. These products are obtained by profiling of previously electrically welded round pipes with a hot sheet stamping or pressure treatment (drawing, cold rolling, stamping). Technological parameters of combined processing methods are determined by the results of experimental research, which, due to the complexity and cost of materials, leads to significant expenses. The application of mathematical modeling can reduce the number of experiments and forecast the quality of finished products. The research focuses on investigating the possibility of obtaining square hollow profiles by means of push-pulling through one stand of a pipe welding unit and defining the requirements for geometric parameters of the billet.

CALCULATION DESIGN AND ADDITIVE MANUFACTURING TECHNOLOGIES OF CHANNELS IN TOOL ELECTRODES

The ways of expanding the area of effective use of electrodes-tools having a complex profile of internal channels for the regulated supply of the working medium to the processing zone are considered. A methodology for calculating the profile and placement of channels for the supply of liquid liquid working medium has been developed and implemented. The need for electrolytes supplied through an electrode-tool has been established for typical applications of electroabrasive, mainly precision, processing of details. It is shown that additive manufacturing technologies of monolithic tools with internal channels of variable geometry providing controlled flow of the working medium and stabilization of the finishing process are the most effective for these purposes. The expediency of using additive technologies for the manufacture of a fast-transferable electric abrasive tool for equipping technological processes of manufacturing products of high complexity, in particular, for the needs of the aviation and space engineering industries, is substantiated. The ways of overcoming the limitations inherent in the finishing abrasive treatment of hard-to-work materials are shown, in particular, the expansion of the possibility of replacing expensive abrasive granules with less scarce ones, the resistance of which during electroabrasive processing is sufficient to obtain a high-resource the tool in the case of using combined technological processes. The use of new types of tools for combined processing methods is justified, where there are practically no force effects on the part and heating of the removal zone of the allowance is eliminated. This makes it possible to expand the use of new technological processes using promising additive technologies, when producing electrode tools, especially for finishing electroabrasive processing.

Experience in machine tool industry of innovative industrial equipment

The experience of creating of domestic machines for combined and laser processing methods is presented. Based on the proposed approach, electrochemical copying and piercing machines, equipment for electrochemical diamond honing, and laser automated technological complexes are created and introduced into industrial production. Keywords:machine tool production, science intensive equipment, phase space, combined usovsv5@mail.ru, zhav33@mail.ru, lyn220@mail.ru, wayne1976@mail.ru

A Comprehensive Evaluation Method for Planning and Design of Self-Sufficient Wind Power Energy Systems at Ports

This study proposes a scientific method to assess the rationality of planning and design of self-sufficient wind power systems (SS-WPSs) at ports. The evaluation method proposed is based on the concept of integrated development of water transportation and a clean energy system, taking into account the demand of the former and the availability of the latter. First, the factors representing the property of the system from the perspectives of economy, environment, energy efficiency, self-sufficiency, and reliability are calculated. The evaluation method is developed by using a combined Analytical Hierarchy Process and Entropy Weight Method (AHP-EWM) to calculate the subjective and objective weights of these factors. Subsequently, a combined weighting method based on game theory is employed with the aim of minimizing deviations between the subjective and objective weights and the combination weights, thereby determining the optimal combination of weights of the evaluation factors. These weights will be used to calculate evaluation results under different planning schemes. To validate the effectiveness of the method, a case study is developed based on a wind power energy demonstration project at a dock of a container port. Study results reveal that Option C, considered in this study, outperforms other options with the highest evaluation score of 0.737. Sensitivity analysis further underscores the reliability of Option C, showing a robust 96.15% probability of achieving the maximum final score within a 20% variation range. This indicates that the case study demonstrates that intuitive and realistic evaluation results can be obtained from the proposed method. These results affirm the practicality of our approach, providing invaluable insights for planners, policymakers, and stakeholders involved in sustainable energy initiatives.

RFID-Based Human Action Recognition Through Spatiotemporal Graph Convolutional Neural Network

Traditional solutions for human action recognition usually rely on sensor or video methods. However, these methods have some limitations, such as inconvenient portability, light intensity influence, privacy protection, etc. In this paper, an RFID-based non-wearable human action recognition scheme is proposed. In order to reduce the occlusion effect of the human body on the signal and increase the diversity of the reflected signal, a tags array is constructed. The data of phase and RSSI are fused as feature data to enhance the diversity of data. Furthermore, a combined processing method is proposed to eliminate thermal noise generated by the equipment and reduce the interference caused by the environment. Then, an action segmentation algorithm is designed to align the RF signals of human action. Finally, an efficient human action signal classification model is constructed using the spatiotemporal graph convolutional neural network (STGCN). Extensive experiments demonstrate that the overall accuracy rate of the system for human action recognition is 92.8%. Compared with the comparative mainstream recognition algorithms, STGCN shows better classification performance in terms of identification precision. In addition, multimodal RFID data fusion also improves the accuracy of identification.

Calculating Heat Release Rates from Lithium-Ion Battery Fires: A Methodology Using Digital Imaging

Measuring flame lengths and areas from turbulent flame flares developing from lithium-ion battery failures is complex due to the varying directions of the flares, the thin flame zone, the spatially and temporally rapid changes of the thermal runaway event, as well as the hazardous nature of the event. This paper reports a novel methodology for measuring heat release rate from flame flares resulting from thermal runaway of electric vehicle lithium-ion modules comprising eight 56.3Ah lithium nickel manganese cobalt (NMC) pouch cells using digital cameras and a newly developed numerical code to process the distortion of the flame size based on distance, direction, and shape. The model is tested with a set of experiments using lithium-ion battery packs and validated with a reference set of measurements using calibration boxes, a method commonly used in the reconstruction of flame areas. The experiments showed that the effect of calibration is large, and thus digital imaging without the appropriate calibration can give very large errors in measurement of flames. The combined imaging and processing method proposed in this work allows the determination of heat release rates from lithium-ion battery packs, one of the most challenging variables to quantify during the failure of a battery pack outside the laboratory. In the example experiment that this method was applied to, almost double the heat released was accounted for, meaning 50% of the total heat released would not have been accounted for without this image processing method.

БЕЗАБРАЗИВНАЯ ЧИСТОВАЯ ОБРАБОТКА ДЕТАЛЕЙ МАШИН КОМБИНИРОВАННЫМИ МЕТОДАМИ

At the moment, traditional processing methods are deeply studied and fully implemented in all branches of mechanical engineering. Many experts believe that in the future we should not expect their large-scale development and new discoveries in this area, and if any appear, they will not be competitive enough. A new global method for the development of technological processes is considered to be the study and widespread introduction into the creation of new technological processes with the introduction of combined processing methods. They try to combine mechanical, chemical, thermal and similar phenomena. Their combined use can give a new breakthrough in the development of metalworking sequence design.

Комбинированные технологии повышения надежности и ресурса изделий авиакосмической техники

The paper considers a major scientific and applied problem of improving the quality and reliability of scientific products by technological methods and means, forming the basis for the production of competitive products of domestic engineering, primarily in the aerospace industry. The analysis of the defect appearance causes in technology and the decrease in its reli-ability at the stages of product life cycle is carried out. Measures were identified to ensure established reliability while maintaining or increasing the resource with minimizing costs at the stage of commercializing by gradually increasing opera-tional characteristics underway product test. It is shown that combined methods of part process allow creating small-sized multilayer vibration-resistant filters with an increased area of the working area and a total wall thickness that ensures the stability of the product to repeated vibrations, which previously caused undesirable increase in the dimensions and mass of a manufactured product. The possibilities of using combined processing methods with the imposition of electromagnetic fields to improve the operational characteristics of upgraded and aircraft parts under formation, including their elements, in the expansion of mass production of scientific products, particularly developed for their import substitution, are found.The change in the mechanical characteristics of materials under various processing methods has been studied. Specimens test for strength at failure and stretch have shown that the consistent use of highly efficient electrochemical sizing followed by jackhammering (or other) way of hardening allows the increase in the characteristics of products up to 10%, achieving a result not lower than that obtained after tooling with hardening.

A New Signal Processing Method Based on Notch Filtering and Wavelet Denoising in Wire Rope Inspection

Wire rope is a necessary tool in practical applications especially in crane, elevator and bridge construction, which plays an important role in the national economy and daily life, and safety inspection for wire rope is the key to ensure people’s life and property. However, detection signals are usually complicated due to the twining structures, which make the wire rope defect signal and strand signal mix together. What’s more, no reports and studies have appeared to solve this problem. In view of the situation and challenges above, this paper proposes a combined signal processing method based on notch filtering and wavelet denoising to process detected wire rope signals. Basic time domain, frequency domain and joint time–frequency analysis are first conducted, thereafter, conventional signal processing methods such as low-pass filtering and adaptive analysis are presented according to the signal characterizations. These comparisons and results demonstrate that a conventional single method is incapable of wire-rope-detection signal identification and differentiation. Nonetheless, after the notch filter design and calculation, the processing results for the typical wire rope inspection signals in the experiments indicate that the combined methods can not only distinguish steel wire rope defect signal and strand signal effectively but also with high detection accuracy, even for the inner defect. Finally, the feasibility and reliability are verified by a series of signal processing results and comparisons, which demonstrate that this new method has great application potential and is of vital significance to the development of wire rope safety inspection.

Research on the particle characteristics of manufactured sands affecting the flow ability of fresh mortar

This paper combined digital image processing (DIP) and discrete element method (DEM) to investigate the relationship between the particle characteristics of manufactured sand and the flow ability of mortar, and clarified the key characteristics parameters of particle shape influencing the flow ability of mortar. A method for batch calculation of shape characteristic parameters (elongation ne, angularity index na and fullness ratio nf) of aggregates based on DIP was proposed. The fluidity tests and corresponding simulations of mortar at different water-cement ratios were carried out respectively, and the results showed that the errors of simulated fluidity (fm) were around 7%. The simulation results demonstrated that the fm decreased with increasing content of large-size aggregates in the mortar. The augment of both ne and na reduced the flowability of mortar. The magnitude of rolling/sliding friction coefficients of aggregates are the important parameters that determine the flowability of mortar.

A combined computer vision and image processing method for surface coverage measurement of shot peen forming

Coverage is an essential monitored parameter during the shot peen forming process. However, the conventional manual visual inspection methods suffer from low efficiency and poor accuracy. In this paper, a combined computer vision and image processing method is applied to realize the automatic measurement of shot peening surface coverage, and the critical issues involved, such as shot peening image pre-processing, indentation light spots recognition, shot-peened area segmentation, etc., are systematically investigated. The results indicate that the influence of machining streaks on the subsequent image processing is effectively reduced by adjusting the illumination conditions and adopting the median filtering algorithm. The number and location of indentations in the shot peening surface image are easily obtained by treating the central light spot as an identifier for the indentation. The features of the shot-peened area can be extracted effectively by segmenting the image reconstructed based on the light spots. The effectiveness of the coverage measurement method is verified by shot peen forming experiments, and the accuracy of the measurement results can be over 97 %. The influence of coverage on shot peening deformation is further examined using the results of algorithm processing, which is reflected in that the radius of curvature decreases with the coverage.

Highly efficient technologies for obtaining small diameter holes in liquid propellant rocket engine parts

The paper considers design and use of parts and assemblies of a liquid propellant rocket engine — a combustion chamber, nozzle head, nozzles. Traditional and advanced technologies for making holes of small diameter in the details of these engines are analyzed. The features of the process of drilling small holes are indicated. The advantages and disadvantages of mechanical processing of component parts and assemblies of a liquid propellant rocket engine, as well as promising methods of electron beam and laser processing are given. It has been found that it is most expedient to obtain small diameter holes in such parts by combining electroerosive and electrochemical methods. The advantages and disadvantages of the combined processing method are described. It is noted that the presented technological processes, already implemented in aerospace production, increase the productivity and accuracy of holes, as well as reduce material and labor costs for the manufacture of special equipment products.

Повышение износостойкости цилиндрических пар трения методом комбинированной обработки

The authors have developed a combined processing method for obtaining modified surfaces. A theoretical and experimental study of surface undulation is presented. Comparative wear tests have shown the advantages of the proposed technology in comparison with traditional hardening methods - HFC hardening and electromechanical processing

Quality characteristics of sweet potato leaves (Ipomoea batatasL.) as influenced by processing and storage conditions

This study investigated the effects of blanching, drying and storage conditions on the quality characteristics of sweet potato leaves (SWPL). SWPL (unblanched and steamed blanched at 90 C for 1 min) were oven-dried (50 C for 72 hours), packaged in polyethylene bags, stored at ambient temperature (28±2 C) and refrigerated (7±2 C) for nine weeks. The rehydration ratio, beta carotene, phenolic content, mineral content, and their soup sensory properties were determined at three weeks intervals using standard methods. Rehydration ratio, beta carotene and phenolic contents ranged from 9.46-10.50, 0.10-0.70 g/100 g and 16.40-29.20 g/100 g respectively. The refrigerated blanched samples contained a greater amount of calcium (496.35) and zinc (1.64) than unblanched samples at the end of nine-week storage. The soups prepared from refrigerated blanched dried SWPL were rated similar to fresh SWPL. The combined processing methods of blanching, drying and refrigeration preserved the nutrients in SWPL with better rehydration and organoleptic properties.