Publikační činnost Katedry obrábění, montáže a strojírenské metrologie / Publications of Department of Working and Assembly (346)

Permanent URI for this collectionhttp://hdl.handle.net/10084/71298

Kolekce obsahuje bibliografické záznamy publikační činnosti (článků) akademických pracovníků Katedry obrábění, montáže a strojírenské metrologie (346) v časopisech registrovaných ve Web of Science od roku 2003 po současnost.
Do kolekce jsou zařazeny:
a) publikace, u nichž je v originálních dokumentech jako působiště autora (adresa) uvedena Vysoká škola báňská-Technická univerzita Ostrava (VŠB-TUO),
b) publikace, u nichž v originálních dokumentech není v adrese VŠB-TUO uvedena, ale autoři prokazatelně v době jejich zpracování a uveřejnění působili na VŠB-TUO.

Bibliografické záznamy byly původně vytvořeny v kolekci Publikační činnost akademických pracovníků VŠB-TUO, která sleduje publikování akademických pracovníků od roku 1990.

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Now showing 1 - 20 out of 321 results

Multi-objective RIME algorithm-based techno economic analysis for security constraints load dispatch and power flow including uncertainties model of hybrid power systems
(Elsevier, 2024) Pandya, Sundaram B.; Kalita, Kanak; Jangir, Pradeep; Čep, Robert; Migdady, Hazem; Chohan, Jasgurpreet Singh; Abualigah, Laith; Mallik, Saurav
In recent times, the landscape of power systems has undergone significant evolution, particularly with the integration of diverse renewable energy sources (RESs). This advancement presents an invaluable opportunity to enhance energy efficiency in the modern power grid, primarily by bolstering the role of stochastic RESs. The challenge lies in the optimal power flow (OPF), a multifaceted and non-linear optimization challenge that grows more complex with the inclusion of stochastic RESs that aims to optimize the allocation of power system resources to minimize the operational cost while maintaining the stability and security of the system. Addressing this, the current study introduces an innovative optimization approach, the Multi-Objective RIME (MORIME) algorithm. Drawing inspiration from the physical phenomenon of rime-ice, called the RIME, the MORIME seeks to effectively tackle OPF issues. This algorithm enhances solution accuracy by smartly dividing with nondominated sorting and crowding distance mechanism. The proposed OPF model incorporates three types of RESs: solar photovoltaic, wind and small-scale hydropower units. While uncertainties in wind speed and solar irradiation are managed through Monte Carlo simulations, the small hydro unit is considered a constant power source. The efficacy of the MORIME algorithm is tested on IEEE 30 bus systems and results indicate that the MORIME method identifies the optimal solution for the multi-objective OPF problem while satisfying the power system constraints, thereby proving its effectiveness and superiority over MOWOA, MOGWO, MOALO, MOMRFO and MOAGDE in terms of Hyper Volume (HV) and reciprocal of Pareto Sets Proximity (1/PSP) metrices. The MORIME source code is available at: https://github.com/kanak02/MORIME
Many-objective grasshopper optimization algorithm (MaOGOA): A new many-objective optimization technique for solving engineering design problems
(Springer Nature, 2024) Kalita, Kanak; Jangir, Pradeep; Čep, Robert; Pandya, Sundaram B.; Abualigah, Laith
In metaheuristic multi-objective optimization, the term effectiveness is used to describe the performance of a metaheuristic algorithm in achieving two main goals-converging its solutions towards the Pareto front and ensuring these solutions are well-spread across the front. Achieving these objectives is particularly challenging in optimization problems with more than three objectives, known as many-objective optimization problems. Multi-objective algorithms often fall short in exerting adequate selection pressure towards the Pareto front in these scenarios and difficult to keep solutions evenly distributed, especially in cases with irregular Pareto fronts. In this study, the focus is on overcoming these challenges by developing an innovative and efficient a novel Many-Objective Grasshopper Optimisation Algorithm (MaOGOA). MaOGOA incorporates reference point, niche preserve and information feedback mechanism (IFM) for superior convergence and diversity. A comprehensive array of quality metrics is utilized to characterize the preferred attributes of Pareto Front approximations, focusing on convergence, uniformity and expansiveness diversity in terms of IGD, HV and RT metrics. It acknowledged that MaOGOA algorithm is efficient for many-objective optimization challenges. These findings confirm the approach effectiveness and competitive performance. The MaOGOA efficiency is thoroughly examined on WFG1-WFG9 benchmark problem with 5, 7 and 9 objectives and five real-world (RWMaOP1- RWMaOP5) problem, contrasting it with MaOSCA, MaOPSO, MOEA/DD, NSGA-III, KnEA, RvEA and GrEA algorithms. The findings demonstrate MaOGOA superior performance against these algorithms.
Experimental investigation on solidification cracking & intergranular corrosion of AISI 321 & AISI 316 L dissimilar weld on pulsed current gas tungsten arc welding (PCGTAW)
(Elsevier, 2024) Patil, Tejas; Bhosale, Ajit; Manikandan, S. G. K.; Jose, Bibin; Naidu, Mithul; Salunkhe, Sachin; Čep, Robert; Nasr, Emad Abouel
Dissimilar metal combinations are frequently employed in the power generation and nuclear industries. Where stainless steel piping systems are connected to pressure vessels made of low- alloy steel, the subsystems of liquid rocket engines also have different, dissimilar material combinations. Dissimilar welding plays a vital role in ensuring the integrity, performance, and reliability of components and structures operating in cryogenic environments, in this study, plates of AISI 316L and AISI 321, each 5 mm thick, were successfully joined using the pulsed current gas tungsten arc welding (PCGTAW) technique with optimized process parameters. These weld joints are mostly present in rocket engines subjected to a cryogenic environment. Due to the low temperature environment, the metallurgical properties of these joints change, which affects their mechanical properties. As it is a structural part, PCGTAW welding is most common method for joining this kind of material. In this work, Microstructural analysis of the weldment revealed a combination of vermicular, lacy, and acicular ferrite morphologies in the fusion zone at the root, mid, and crown locations. Furthermore, no solidification cracking was detected in the weldments based on the optical micrograph and SEM results. Intergranular corrosion (IGC) testing indicated the absence of a ditch structure, suggesting that the heat-affected zone (HAZ) on both sides of the weld joint was not being susceptible to sensitization. However, the HAZ of the AISI 316L side exhibited coarser grains compared to AISI 321. Analysis of tensile properties revealed a significant influence of the testing environment on the tensile strength of the dissimilar welded joints. At room temperature, the average ultimate tensile strength (UTS) was measured as 621 MPa. Remarkably, at cryogenic conditions, the average tensile properties significantly increased to 1319 MPa. Microhardness analysis showed the highest hardness associated with the AISI 321 side. The fusion zone exhibited a large deviation in the hardness profile (205 +/- 10 HV), with the highest average hardness observed in the middle part of the weld. However, the hot cracking behavior of the weld was investigated by using a suutula diagram at various locations of the weld. The investigation revealed that the Creq/Nieq eq /Ni eq ratio exceeded the critical threshold value, effectively diminishing the propensity for hot cracking in the fusion zone. Overall, these findings underscore the effectiveness of the PCGTAW technique in joining dissimilar materials, as well as the importance of microstructural and mechanical property evaluations, especially under extreme operating conditions such as cryogenic temperatures.
Many-objective ant lion optimizer (MaOALO): A new many-objective optimizer with its engineering applications
(Elsevier, 2024) Kalita, Kanak; Pandya, Sundaram B.; Čep, Robert; Jangir, Pradeep; Abualigah, Laith
Many-objective optimization (MaO) is an important aspect of engineering scenarios. In manyobjective optimization algorithms (MaOAs), a key challenge is to strike a balance between diversity and convergence. MaOAs employs various tactics to either enhance selection pressure for better convergence and/or implements additional measures for sustaining diversity. With increase in number of objectives, the process becomes more complex, mainly due to challenges in achieving convergence during population selection. This paper introduces a novel ManyObjective Ant Lion Optimizer (MaOALO), featuring the widely-popular ant lion optimizer algorithm. This method utilizes reference point, niche preserve and information feedback mechanism (IFM), to enhance the convergence and diversity of the population. Extensive experimental tests on five real-world (RWMaOP1- RWMaOP5) optimization problems and standard problem classes, including MaF1-MaF15 (for 5, 9 and 15 objectives), DTLZ1-DTLZ7 (for 8 objectives) has been carried out. It is shown that MaOALO is superior compared to ARMOEA, NSGA-III, MaOTLBO, RVEA, MaOABC-TA, DSAE, RL-RVEA and MaOEA-IH algorithms in terms of GD, IGD, SP, SD, HV and RT metrics. The MaOALO source code is available at: https://github.com/kanak02/MaOALO.
Exploring electrospun Nafion nanofibers: Bibliographic insights, emerging possibilities, and diverse applications
(AIP Publishing, 2024) Avvari, Venkata Dinesh, VENKATA DINESH; Sreekanth, P. S. Rama; Shanmugam, Raghavanantham; Salunkhe, Sachin; Čep, Robert; Nasr, Emad Abouel; Kimmer, D.
Over the past several decades, there has been a significant surge in interest regarding the use of organic-inorganic hybrid polymers and nanocomposite membranes. The reasons for this are improved attributes, reduced costs, and the additional stability the influence membrane provides. This Review outlines the various techniques and methodologies used to prepare Nafion and its composites, delineating the promising benefits of the electrospinning process. Electrospinning has emerged as a versatile and promising technique for fabricating nanofibers with unique properties and wide-ranging applications. This study explores the electrospinning of Nafion, a perfluorosulfonic acid polymer widely known for its exceptional proton conductivity and chemical stability, into nanofibrous structures, unlocking new possibilities yet unknown features of its inherent properties. The morphology and chemical structure of the resulting nanofibers is analyzed. A thorough bibliographic analysis of electrospun Nafion was presented using the PRISMA approach for methodically presenting the report. Network visualization of connected authors and categorizing application-specific publications are also discussed. Moreover, the electrospinning parameters and blends are systematically investigated to optimize the production of Nafion nanofibers for various applications in fuel cells, water treatment, actuators, sensors, and energy harvesting. The challenges involved in electrospinning Nafion, Nafion nanocomposites, and their variants are also presented, with a discussion delineating the future scope. This work concludes by emphasizing the interdisciplinary character of the Nafion polymer and its composites, connecting materials science and the intricate issues presented by various sectors.
Exploring fabrication strategies and innovative applications of ionic polymer metal composites: state-of-the-art review
(IOP Publishing, 2024) Sridhar, Yesaswi Ch; Avvari, Venkata Dinesh, VENKATA DINESH; Sahu, Santosh Kumar; Sreekanth, P. S. Rama; Barick, Aruna Kumar; Salunkhe, Sachin; Čep, Robert; Abouel Nasr, Emad
Various studies have been conducted to investigate the development of sustainable materials that possess the ability to respond to specific stimuli while preserving their original form. Electric energy is the most appealing way to stimulate Ionic Polymer Metal Composites (IPMC), allowing them to act as actuators and sensors. IPMCs are excellent alternatives despite challenging manufacturing conditions due to their good strain rates, quick responsive nature, high reliability, and mechanical compatibility. IPMC materials are highly sought after for their bio-inspired features. Researchers are developing IPMC materials that can act as thrusters, which entails establishing scientific and engineering groundwork and grasping operational principles. Nonetheless, a substantial understanding of the factors affecting their competence and persistence has been achieved through these efforts. Moreover, there is progress in developing effective processing techniques to fabricate IPMC. In this paper, IPMC mechanisms and respective fabrication techniques are reviewed in brief. Similarly, applications of the IPMCs in various fields are also discussed.
An experimental and modelling approach to proclaim sustainable machining using avocado oil-based nano-cutting fluids
(Springer Nature, 2025) Anebo, Abera Ayza; Chenrayan, Venkatesh; Shahapurkar, Kiran; Gebremaryam, Gezahgn; Petrů, Jana; Soudagar, Manzoore Elahi M.; Bhaviripudi, Vijayabhaskara Rao; Rajagopal, Rajakrishnan; Bashir, Muhammad Nasir
Higher-end science and technology facilitate the human community with a sophisticated life despite it curses by abundant pollution. The alarming demand for sustainability pressurizes the manufacturing sector to ensure sustainable manufacturing. Since Molybdenum di sulfide (MoS2) and avocado oil are known solid and liquid lubricants respectively, hence, it is a worthwhile attempt to implement the bio-based degradable avocado oil enriched with nano Molybdenum di sulfide (nMoS2) particles as a potential machining fluid for CNC-end milling. Different proportions of avocado oil and nMoS2 were used to synthesise four distinct machining fluids to assess the individual impact of avocado oil and nMoS2 particles. The emulsification and sonication were employed to synthesise the fluids. A hybrid Grey Relational Analysis (GRA) coupled with Principal Component Analysis (PCA) was followed to scrutiny the effect of novel machining fluid on machining objectives. The experimental results of physio-chemical properties revealed that avocado-rich 0.5% nMoS2 excels among others. The L16 orthogonal array experiments associated with statistical analysis explored the developed machining fluid (A6W4/0.5) that significantly impacts the machining objectives. The experimental results manifest that nearly 64.87% of surface roughness and 93.3% of tool wear have been reduced during machining in the presence of A6W4/0.5 fluid than A4W6/0.75. The improved performance of the novel machining fluid upholds its potential to replace conventional fluids and ensure green manufacturing.
MORKO: A multi-objective Runge-Kutta optimizer for multi-domain optimization problems
(Springer Nature, 2025) Kalita, Kanak; Jangir, Pradeep; Pandya, Sundaram B.; Alzahrani, Ahmed Ibrahim; Alblehai, Fahad; Abualigah, Laith; Ezugwu, Absalom E.
In the current landscape, there is a rapid increase in the creation of new algorithms designed for specialized problem scenarios. The performance of these algorithms in unfamiliar or practical settings often remains untested. This paper presents a new development, the multi-objective Runge-Kutta optimizer (MORKO), which is built upon the principles of elitist non-dominated sorting and crowding distance. The goal is to achieve superior efficiency, diversity, and robustness in solutions. MORKO effectiveness is further enhanced by incorporating various strategies that maintain a balance between diversity and execution efficiency. This approach not only directs the search toward optimal regions but also ensures that the process does not become stagnant. The efficiency of MORKO is compared against renowned algorithms like the multi-objective marine predicator algorithm (MOMPA), multi-objective gradient-based optimizer (MOGBO), multi-objective evolutionary algorithm based on decomposition (MOEA/D), and non-dominated sorting genetic algorithm (NSGA-II) on several test benchmarks such as ZDT, DTLZ, constraint (CONSTR, TNK, SRN, BNH, OSY and KITA) and real-world engineering design (brushless DC wheel motor, safety isolating transformer, helical spring, two-bar truss, welded beam, disk brake, tool spindle and cantilever beam) problems. We used unique, non-overlapping performance metrics for this comparison and suggested a fresh correlation analysis technique for exploration. The MORKO algorithm outcomes were rigorously tested and confirmed using the non-parametric statistical evaluations. The MORKO algorithm proves to excel in deriving comprehensive and varied solutions for many tests and practical challenges, owing to its multifaceted features. Looking ahead, MORKO has potential applications in complex engineering and management tasks.
Stiffness and stability of bamboo stem - A optimal design perspective
(Elsevier, 2024) Sayyad, Mannan; Bachchhav, Bhanudas; Salunkhe, Sachin; Čepová, Lenka; Struž, Jiří; Nasr, Emad Abouel; El Mola, Khaled M. S. Gad
During the evolution process, a bamboo stem achieves a significant height (up to 20 m) to fulfil its phototropic requirements. While on land, the stem is mostly subjected to bending load which makes it liable to fail by uprooting. However, this failure is prohibited by smart structure of bamboo stem which includes graded arrangement of fibre bundles in the cross-section and a tapered cantilever form of the stem. This paper attempts to understand the optimal design of bamboo stem through the relationship between the stellar arrangement of stiff fibre bundles in the cross-section and the tapered form. In this work, a comparison between two types of stellar arrangement, namely uniform and graded, is presented in view of non-linear bending analysis through elastica theory and fracture-induced delamination, both numerically. It is observed from the results that a bamboo stem prefers to evolve with graded stellar arrangement which provides gradation of stiffness and toughness over the cross-section; the trend in toughness being opposite to that of stiffness. Moreover, interplay of stellar arrangement and gradation of stiffnesstoughness thereof is found to be the governing mechanism for ensuring its mechanical integrity and stability in view of an optimal design perspective. The smart structure of bamboo is recommended for bio-mimicking.
Analysis of the thickness of layered armor to provide protection against 7.62 mm ball projectiles using experimental and numerical methods
(Frontiers Media S.A., 2024) Morghode, Divyanshu S.; Thakur, D. G.; Salunkhe, Sachin; Čepová, Lenka; Nasr, Emad Abouel
The layered configuration of different material plates is one of the ways of achieving protection against different kinds of kinetic energy ammunitions. The thickness of each plate is one of the most important influencing parameters to prevent the penetration of the projectile. In the present study, a layered configuration of the Al2O3 and Al 7075-T651 is analysed, to prevent the perforation of 7.62 mm Lead core projectile, under normal impact conditions, by using LS-DYNA numerical simulations. Experiments were conducted on Al 7075-T651 plate and Numerical model was validated with experiment results. To achieve the objective, the validated numerical model was used to investigate influence on various Al2O3 and Al 7075-T651 combinations. Three factors led to the selection of Al 7075-T561 and Al2O3 as the target materials. First, the literature review revealed that these materials have already been employed in the construction of armour. Second, Al2O3 is a brittle material whereas Al 7075-T651 is ductile. Consequently, when combined in a layered arrangement, these materials offer the ideal destroyer-absorber arrangement. Thirdly, these materials have lower densities than steel. As a result, these materials offer a lightweight alternative for lead core 7.62 mm bullet defense. From the analysis, it is observed that two layered configurations were found to be effective in the prevention of bullet perforation: a front plate of Al2O3 that was 10 mm thick and had a rear plate of Al 7075-T651 that was 06 mm thick, and a front plate of Al2O3 that was 04 mm thick and had a 12 mm thick layer of Al 7075-T651.
Continuous filament fabrication technology and its mechanical properties for thin-walled component
(MDPI, 2026) Kozior, Tomasz; Bochnia, Jerzy; Hajnyš, Jiří; Měsíček, Jakub
The aim of the presented research is to assess the possibility of manufacturing thin-walled models using innovative 3D printing technology and to determine limitations. This article presents the results of tensile tests of the Continuous Filament Fabrication (CFF) technology for thin-walled sample models. Two types of materials were tested. The first material is pure ONYX based on polyamide, and the second is ONYX with an additional core made of carbon fiber. The paper presents the limitations of using the core in thin-walled structures, and for pure ONYX material, samples were made with different orientations on the 3D printer platform, which allowed determining the effect of the printing direction on the mechanical properties of the samples. In addition, microscopic photographs of the fracture of the broken samples were taken in the paper, based on which the defects of the technological process were identified. It was shown that the strength of thin-walled samples (1 mm, 1.4 mm, and 1.8 mm thick) printed in the Y direction is significantly greater than that of samples printed in the X and Z directions. For example, for 1 mm thick samples printed in the Y direction, the strength is 49.02 MPa, while for samples printed in the X and Z directions, it is 27.71 MPa and 21.28 MPa, respectively. The strength of samples (4 mm thick) reinforced with ONYX + OCF carbon fiber printed in the X direction is 191.36% greater than that of samples made of pure ONYX.
Design and analysis of automatic whole row tomato seedling transplanter technology with integrated controlling system
(Wiley, 2026) Ali, Addisu Negash; Nigus, Messele Gashaye; Paramasivam, Velmurugan; Petrů, Jana; Čep, Robert
In the small-scale farming, transplantation of tomato is performed manually using hand drilling without considering the standard agronomy practices. To develop innovative products with reduced size and automatic operations, the analysis and design of the feeding, picking, and planting components of the automatic transplanting machine need to be the focus area. The integrated approaches of conceptual design, concepts evaluation and selection, synthesis and numerical modeling of mechanisms, path manipulator design, components and assembly SolidWorks modeling, Matlab and ADAMS software validation simulations, and PLC based control system design are used to develop the target technology. During design and analysis, a 128 cell standard plug tray, 42 mm grid depth, 110 mm average seedling height, 35 cm plant spacing, 40 cm row spacing, and 192 seedlings/min planting capacity were selected as design criteria. The results from kinematics analysis and optimal design of gripper indicated that the clamping and insertion angles should be in the ranges of 16 degrees-22 degrees and 10.6 degrees-14.8 degrees respectively to prevent damage. Furthermore, the optimum clamping angle (beta) and insertion angle (alpha) were found to be 20 degrees and 13.4 degrees respectively for successful clamping and picking of seedlings. A combination of linear and fourth order polynomial models have been developed to provide accurate trajectory plans for the path manipulator. The ADAMS software simulation results are directly fitted with the theoretical results, and the modeling of the seedling pickup mechanisms provides a basis for future bench tests. For a standard 128 cells plug tray, and target frequency of 192 seedlings/min, the pickup device with eight grippers is designed to effectively pick the whole row of tomato seedlings within 2.5 s. Finally, to synchronize the transplanting operations and ensure a continuous supply of signals, photoelectric positioning sensors, magnetic switches, pneumatic components, and PLC control unit are selected and positioned at the optimum locations.
Development of optimally reinforced glass/bamboo fiber and rice husk/bagasse filler Agrostone composite panels for interior panel applications
(Wiley, 2026) Ali, Addisu Negash; Yityaw, Abebaw Abiyu; Paramasivam, Velmurugan; Rao, D. K. Nageswara
Agrostone panels, popularly used for interior walls in construction, are usually made from sustainable agricultural waste such as bagasse as filler and glass fiber as reinforcement in a binder of pumice, MgO, and MgCl2 solutions. The present work has gone ahead of one step by adding rice husk and bamboo fiber, which are abundantly available in Ethiopia, in addition to bagasse and glass fiber. It is aimed to investigate the effect of rice husk and bamboo fiber additives. Initial optimized parameters are obtained for two variables in three levels from the central composite design (CCD), and the samples are prepared for the design of experiments. Regression analysis and ANOVA are conducted using the experimental data. The data from ANOVA is fed to response surface methodology (RSM) to obtain the final optimized proportions of reinforcement fibers and fillers for the highest mechanical properties without changing the proportions of matrix materials. Using the proportions from RSM, the specimens are prepared for the final evaluation of mechanical properties. Weight percentages of bamboo fibers (0, 1.1, and 2.2) and rice husk (0, 3.515, and 7.03) are given by RSM. The optimization process in CCD consists of three levels for two variables in terms of weight percentage. The results show that 3.091 and 1.358 wt.% of rice husk and bamboo fiber, respectively, gave the highest tensile, compressive, flexural, and impact strength values of 64.92 MPa, 75.534 MPa, 65.168 MPa, and 63.485 J, respectively. The corresponding comparable values from the experiment are 65.02, 74.73, 73.42, and 63.95 MPa, respectively.
Behavior of CuO as solid lubricant inside ZTA matrices
(AIP Publishing, 2024) Singh, Bipin Kumar; Kumar, Amit; Čep, Robert; Kumar, Ajay; Kumar, Ashwini; Dogra, Namrata; Logesh, K.
This investigation delves into the behavior of copper oxide (CuO) as a solid lubricant inside zirconia toughened alumina (ZTA) ceramic composites. The investigation starts with the preparation of ZTA through co-precipitation followed by powder metallurgy to develop CuO (1.5 wt. %)/ZTA composites. In all cases, hot isotactic pressing is applied for densification. The fully densified samples are thoroughly mirror-polished to investigate the mechanical and tribological properties. A 1.8% reduction in micro-hardness and 6% improvement in fracture toughness are observed with incorporation of CuO into the ZTA matrices. The analysis reveals that the presence of ionic copper at the grain boundary leads to the formation of copper-rich phases, causing a decrease in hardness. However, the softer CuO particles contribute to crack bridging and crack deflection, enhancing fracture toughness. Subsequent investigation into the tribological properties highlights the positive influence of the softer CuO phases acting as a secondary component within the ZTA matrix. A significant enhancement of 39.34% in the Coefficient of Friction (COF) is achieved by incorporating CuO into the ZTA matrix. This improvement can be attributed to the formation of a patchy layer through smearing and squeezing actions on wear debris during sliding. The uniform patchy layer results in smoother and more polished surfaces, leading to an improvement in both the COF and specific wear rate. Further wear analysis reveals various phenomena contributing to surface wear, including pullout of grain particles, micro-fracture, high abrasions, and laminar removal of grains. Overall, the introduction of CuO proves to be beneficial, showcasing improved mechanical and tribological properties in the developed composites, with application in dies, inserts, sparkplugs, etc.
Design and development of thermo-electromagnetic system for spinodal decompositions of FeCrCo alloys
(Elsevier, 2024) Haider, Ali; Khan, Muhammad Ali; Jaffery, Syed Husain Imran; Faraz, Muhammad Iftikhar; Jameel, Mohammed; Petrů, Jana; Saydaxmetova, Shaxnoza
Permanent magnets are essential components of electromechanical devices. Majority of magnets are used in permanent magnet motors that have extensive application in relation to energy efficiency and sustainability like electric vehicles. This research is aimed for efficient manufacturing of FeCrCo permanent magnets. Electromagnets could be utilized for the generation of continuous magnetic field to use in number of manufacturing processes. A two-pole electromagnet, comprising of two solenoids each having 2200 turns of copper wire, was developed. The system was designed to produce magnetic field up to 10 kilo Gauss for spinodal decomposition of FeCrCo alloy samples under thermomagnetic treatment process. Being rare earth free alloys, FeCrCo magnet is gaining research focus as an alternative magnetic alloy for advanced applications. The electromagnetic system design was refined and confirmed by using the Finite Element Method. The experimental values, of magnetic field generated by the two-pole electromagnet setup, were well close to the simulation results. The magnetizing setup was utilized to treat the FeCrCo magnetic alloy samples simultaneously at high temperature (700 degrees C) and magnetic field (7 kilo Gauss). This thermo-magnetic setup helped to improve the metallurgical structures of FeCrCo to grow and develop more efficiently. Treated samples of FeCrCo alloy demonstrated enhanced magnetic properties due to effective spinodal decomposition. The improvement in magnetic properties was attributed to the elimination of retained alpha phase and formation of more alpha-1 phase.
Determination of the brittleness of glass fibers on selected mechanical and rheological properties of the polymer composite
(Budapest University of Technology and Economics, Faculty of Mechanical Engineering, Department of Polymer Engineering, 2024) Miščík, Stanislav; Dobránsky, Jozef; Gombár, Miroslav; Čep, Robert
The paper deals with the influence of the brittleness of glass fibers on the selected performance properties of the fibrous polymer composite. Understanding the fatigue behavior of fiber-reinforced plastics is desirable for exploiting their features in safe, durable, and reliable industrial components. Based on the proposed methodology, it is possible to assess the impact of material reuse on selected mechanical and rheological properties. To verify the methodology by experimental analysis, homopolymer PP reinforced with chemically grafted glass fiber (30 wt%) was selected. The proposed methodology was subsequently verified by experimental analysis and evaluated statistically. The morphology of the fracture surfaces was evaluated, and the fiber-polymer matrix adhesion was monitored at the interface of the fracture surfaces. Based on the measured and evaluated values and fracture surfaces, we can say that the brittleness of the fibers significantly affects the performance properties of the tested polymer composite.
Proposes geometric accuracy and surface roughness estimation of anatomical models of the pelvic area manufactured using a material extrusion additive technique
(MDPI, 2025) Turek, Paweł; Snela, Sławomir; Budzik, Grzegorz; Bazan, Anna; Jarosław Jabłoński; Przeszłowski, Łukasz; Wojnarowski, Robert; Dziubek, Tomasz; Petrů, Jana
One of the main benefits of using 3D printing in orthopedics is the ability to create custom solutions tailored to a patient’s specific anatomical and functional needs. Conducting a reliable evaluation of the accuracy of the manufacture of anatomical structure models is essential. However, particular standards or procedures still need to be implemented to control the surface quality of anatomical models manufactured using additive manufacturing techniques. Models of pelvic parts made of polylactic acid (PLA) material were manufactured using the Material Extrusion (MEX) additive technique. Subsequently, guidelines were developed to reliably verify the geometric and surface roughness of the 3D printed models using Computer-Aided Inspection (CAI) systems. For this purpose, a measuring arm system (MCA-II) with a mounted laser head and Atos II Triple Scan was used. To inspect surface roughness parameters, procedures were developed for an Alicona InfiniteFocusG4 optical microscope. The results of the geometrical verification of the models are within the tolerance limits of ±0.22 mm to ±0.6 mm. In the case of surface roughness measurement, the highest values for the arithmetical mean height Sa were obtained on the side of the support material, while the smallest values were found along the applied layers. After the metrological control process, the models were used in the planning process for hip surgery.
Maximization of wear rates through effective configuration of standoff distance and hydraulic parameters in ultrasonic pulsating waterjet
(University of Niš, 2024) Nag, Akash; Dixit, Amit Rai; Petrů, Jana; Váňová, Petra; Konečná, Kateřina; Hloch, Sergej
A pulsating waterjet is a technological modification of a conventional waterjet that utilizes ultrasonic vibrations to generate a modulated jet, resulting in repetitive fatigue loading of the material. The erosion efficiency of the ultrasonic pulsating waterjet is majorly determined by the hydraulic factors and its interaction with standoff distance. However, the dependency of the wear rates on different hydraulic factors and formulation of an implicit prediction model for determining effective standoff distance is still not present to date. Therefore, in this study, the combined dependency of the supply pressure (20-40 MPa), nozzle diameter (0.3-1.0 mm), and standoff distance (1-121 mm) on wear rates of AW-6060 aluminum alloy are studied. Statistical analysis is used to determine the statistically significant factors and formulate regression equations to determine output responses within the experimental domain. The surface topography and sub-surface microhardness of the eroded grooves were studied. The results show that both the disintegration depth and the material removal increase with an increase in the nozzle diameter and supply pressure. However, the dependency of the output responses on nozzle diameter is statistically more evident than supply pressure and two-way interactions. Cross-sectional images of the grooves showed typical hydrodynamic erosion characteristics in erosion cavities, subsurface voids, and material upheaving. The results of microhardness analysis showed an approximately 15-20% increase in hardness values compared to the untreated samples.
Submerged surface texturing of AISI 304L using the pulsating water jet method
(Springer Nature, 2024) Stolárik, Gabriel; Klichová, Dagmar; Poloprudský, Jakub; Chlupová, Alice; Nag, Akash; Hloch, Sergej
Submerged jets have a variety of practical applications due to their versatility in providing efficient and environmentally friendly options for treatment in various industries. The physical background is based on the continuous water jet (CWJ) application powered via stagnation pressure. However, it is known that impact pressure is much more effective than static pressure. When the impact pressure is repeated with a high frequency per time unit, the erosive effects of water can be used even at pressures below 100 MPa, which is attractive from the point of view of the low demands of the hydraulic system. Surface modification utilising impact pressure can be achieved by employing the pulsed water jet (PWJ) method. The combination of parameters such as the traverse speed and trajectory pattern can control the number of water clusters impacting the material surface. So far, the field of application of PWJ for surface treatment has mostly been investigated water atmospheric conditions. This article focuses on the possibility of the surface modification of AISI 304L stainless steel using the PWJ method under submerged conditions. The results are compared to those obtained under atmospheric conditions. The reference samples were treated by the same technological conditions using a continuous water jet (CWJ). The affected surfaces were characterised using areal surface roughness parameters Sa, Sz, Sp, and Sv, and the surface topography and mechanism of erosion wear were evaluated by scanning electron microscopy. A significant increase in all roughness parameters was confirmed using the PWJ compared to the CWJ method (both in atmospheric and submerged conditions), which confirms the importance of using impact pressure. The surface treatment by PWJ under submerged conditions resulted in a decrease of the surface roughness parameter Sa by approximately 97% compared to atmospheric conditions at a traverse speed of 2 mm/s for perpendicular interleaved trajectory, nevertheless, the homogeneity of treatment over a larger area was improved.
Study of eddy current testing ability on SLM aluminium alloy
(MDPI, 2024) Gel’atko, Matúš; Hatala, Michal; Botko, František; Vandžura, Radoslav; Hajnyš, Jiří
The detection of defects in aluminium alloys using eddy current testing (ECT) can be restricted by higher electrical conductivity. Considering the occurrence of discontinuities during the selective laser melting (SLM) process, checking the ability of the ECT method for the mentioned purpose could bring simple and fast material identification. The research described here is focused on the application of three ECT probes with different frequency ranges (0.3-100 kHz overall) for the identification of artificial defects in SLM aluminium alloy AlSi10Mg. Standard penetration depth for the mentioned frequency range and identification abilities of used probes expressed through lift-off diagrams precede the main part of the research. Experimental specimens were designed in four groups to check the signal sensitivity to variations in the size and depth of cavities. The signal behavior was evaluated according to notch-type and hole-type artificial defects' presence on the surface of the material and spherical cavities in subsurface layers, filled and unfilled by unmolten powder. The maximal penetration depth of the identified defect, the smallest detectable notch-type and hole-type artificial defect, the main characteristics of signal curves based on defect properties and circumstances for distinguishing between the application of measurement regime were stated. These conclusions represent baselines for the creation of ECT methodology for the defectoscopy of evaluated material.

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