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Prof. Angelos Markopoulos
National Technical University of Athens, Greece

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Research Keywords & Expertise

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0 Machining
0 Manufacturing Engineering
0 Milling
0 Modeling and Simulation

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Machining
Grinding
Milling
Modeling and Simulation
Hard turning
Finite Element Analysis (FEA)

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Short Biography

Angelos P. Markopoulos is an Assistant Professor in the Laboratory of Manufacturing Technology at the School of Mechanical Engineering, National Technical University of Athens, Greece. His research includes topics such as precision and ultraprecision conventional and non-conventional machining processes, with a special interest in advanced manufacturing and Industry 4.0. Furthermore, he is an expert in manufacturing technology modeling and simulation, including the finite element method, artificial intelligence, and molecular dynamics. He is the author of more than 120 papers in journals, conferences, and book chapters on the above-mentioned areas, and a member of the editorial boards of several international journals.

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Journal article
Published: 09 August 2021 in Sustainability
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Abrasive Waterjet Machining (AWJM) is considered a viable alternative to conventional machining processes, due to its capability of rendering even complex features on parts with high productivity. However, it is currently also important for manufacturing processes to comply with the various aspects of sustainability, by putting emphasis on the environmental dimension apart from the economic. Although AWJM generally is considered an inherently environmentally friendly process, it is required that thorough experimental studies be carried out to evaluate the sustainability of AWJM under various conditions. In the present work, AWJM experiments under various conditions were conducted on a Ti-6Al-4V workpiece in order to determine the optimal conditions leading to a high degree of sustainability in this process based on several indicators. The experiments were carried out using glass beads, which act as an eco-friendly abrasive. After the basic outcome of the experiment was analyzed to determine the correlations between process parameters and depth of penetration, kerf width, and kerf taper angle, sustainability analysis with the aid of Grey Relational Analysis (GRA) was conducted. The optimum solution provided a sufficiently high score regarding both the economic and environmental dimensions of sustainability.

ACS Style

Nikolaos E. Karkalos; Panagiotis Karmiris-Obratański; Rafał Kudelski; Angelos P. Markopoulos. Experimental Study on the Sustainability Assessment of AWJ Machining of Ti-6Al-4V Using Glass Beads Abrasive Particles. Sustainability 2021, 13, 8917 .

AMA Style

Nikolaos E. Karkalos, Panagiotis Karmiris-Obratański, Rafał Kudelski, Angelos P. Markopoulos. Experimental Study on the Sustainability Assessment of AWJ Machining of Ti-6Al-4V Using Glass Beads Abrasive Particles. Sustainability. 2021; 13 (16):8917.

Chicago/Turabian Style

Nikolaos E. Karkalos; Panagiotis Karmiris-Obratański; Rafał Kudelski; Angelos P. Markopoulos. 2021. "Experimental Study on the Sustainability Assessment of AWJ Machining of Ti-6Al-4V Using Glass Beads Abrasive Particles." Sustainability 13, no. 16: 8917.

Journal article
Published: 29 July 2021 in Machines
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3D printing is a process that has become widely used in recent years, allowing the production of parts with relatively complicated shapes from metallic and non-metallic materials. In some cases, it is challenging to evaluate the ability of 3D printers to make fine details of parts. For such an assessment, the printing of samples showing intersections of surfaces with low angle values was considered. An experimental plan was designed and materialized to highlight the influence of different factors, such as the thickness of the deposited material layer, the printing speed, the cooling and filling conditions of the 3D-printed part, and the thickness of the sample. Samples using areas in the form of isosceles triangles with constant height or bases with the same length, respectively, were used. The mathematical processing of the experimental results allowed the determination of empirical mathematical models of the power-function type. It allowed the detection of both the direction of actions and the intensity of the influence exerted by the input factors. It is concluded that the strongest influence on the printer’s ability to produce fine detail, from the point of view addressed in the paper, is exerted by the vertex angle, whose reduction leads to a decrease in printing accuracy.

ACS Style

Andrei Mihalache; Gheorghe Nagîț; Laurențiu Slătineanu; Adelina Hrițuc; Angelos Markopoulos; Oana Dodun. Evaluation of the Ability to Accurately Produce Angular Details by 3D Printing of Plastic Parts. Machines 2021, 9, 150 .

AMA Style

Andrei Mihalache, Gheorghe Nagîț, Laurențiu Slătineanu, Adelina Hrițuc, Angelos Markopoulos, Oana Dodun. Evaluation of the Ability to Accurately Produce Angular Details by 3D Printing of Plastic Parts. Machines. 2021; 9 (8):150.

Chicago/Turabian Style

Andrei Mihalache; Gheorghe Nagîț; Laurențiu Slătineanu; Adelina Hrițuc; Angelos Markopoulos; Oana Dodun. 2021. "Evaluation of the Ability to Accurately Produce Angular Details by 3D Printing of Plastic Parts." Machines 9, no. 8: 150.

Journal article
Published: 17 June 2021 in Machines
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The rotational motion of the medium granules under the influence of an impeller installed in the bottom of a cylindrical reservoir is considered. The dependencies of the circulation velocity of the abrasive granules, as well as the dependence of the pressure in the circulation flow of the granules on the radius of the vibrating machine cylindrical reservoir for different speeds of the impeller rotation are obtained. Furthermore, the velocities of the abrasive granules at various distances from the center of the cylindrical reservoir of the vibrating machine have been determined. The amplitudes of the tangential and radial components of the velocity of movement of pseudo-gas from abrasive granules are obtained. The total pressure on the surface of the processed part and the average velocity of the abrasive granules colliding with it are determined. The graphical dependencies of the integral metal removal on the amplitude and frequency of oscillations of the walls of the vibrating machine reservoir are given for various values of the angular velocities of the impeller rotation.

ACS Style

János Kundrák; Andrey Mitsyk; Vladimir Fedorovich; Angelos Markopoulos; Anatoly Grabchenko. Simulation of the Circulating Motion of the Working Medium and Metal Removal during Multi-Energy Processing under the Action of Vibration and Centrifugal Forces. Machines 2021, 9, 118 .

AMA Style

János Kundrák, Andrey Mitsyk, Vladimir Fedorovich, Angelos Markopoulos, Anatoly Grabchenko. Simulation of the Circulating Motion of the Working Medium and Metal Removal during Multi-Energy Processing under the Action of Vibration and Centrifugal Forces. Machines. 2021; 9 (6):118.

Chicago/Turabian Style

János Kundrák; Andrey Mitsyk; Vladimir Fedorovich; Angelos Markopoulos; Anatoly Grabchenko. 2021. "Simulation of the Circulating Motion of the Working Medium and Metal Removal during Multi-Energy Processing under the Action of Vibration and Centrifugal Forces." Machines 9, no. 6: 118.

Journal article
Published: 15 June 2021 in Cutting & Tools in Technological System
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Electrical discharge machining is one of the most important non-conventional machining processes for removing material from electrically conductive materials by the use of controlled electric discharges. EDM is a non-contact machining process, therefore, is free from mechanical stresses. This paper investigates the machining Al7075-T6 alloy by EDM using a copper electrode. Al7075-T6 alloy was selected, because of its growing use in a lot of engineering applications. The effect of electrical parameters, peak current and pulse-on time, on the surface integrity, was studied. Area surface roughness parameters (arithmetical mean height, Sa, and maximum height, Sz) were measured on all samples and 3D surface characterization has been carried out with confocal laser scanning microscopy. The experimental results showed that the surface roughness is mainly affected by the pulse-on time.

ACS Style

Maria Balanou; Lazaros-Emmanouil Papazoglou; Angelos P. Markopoulos; Panagiotis Karmiris-Obratański. EXPERIMENTAL INVESTIGATION OF SURFACE TOPOGRAPHY OF AL7075-T6 ALLOY MACHINED BY EDM. Cutting & Tools in Technological System 2021, 3 -10.

AMA Style

Maria Balanou, Lazaros-Emmanouil Papazoglou, Angelos P. Markopoulos, Panagiotis Karmiris-Obratański. EXPERIMENTAL INVESTIGATION OF SURFACE TOPOGRAPHY OF AL7075-T6 ALLOY MACHINED BY EDM. Cutting & Tools in Technological System. 2021; (94):3-10.

Chicago/Turabian Style

Maria Balanou; Lazaros-Emmanouil Papazoglou; Angelos P. Markopoulos; Panagiotis Karmiris-Obratański. 2021. "EXPERIMENTAL INVESTIGATION OF SURFACE TOPOGRAPHY OF AL7075-T6 ALLOY MACHINED BY EDM." Cutting & Tools in Technological System , no. 94: 3-10.

Journal article
Published: 07 June 2021 in Manufacturing Technology
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ACS Style

Janos Kundrak; Andrey V. Mitsyk; Vladimir A. Fedorovich; Angelos P. Markopoulos; Anatoly I. Grabchenko. Modeling the energy action of vibration and centrifugal forces on the working medium and parts in a vibration machine oscillating reservoir with an impeller. Manufacturing Technology 2021, 21, 364 -372.

AMA Style

Janos Kundrak, Andrey V. Mitsyk, Vladimir A. Fedorovich, Angelos P. Markopoulos, Anatoly I. Grabchenko. Modeling the energy action of vibration and centrifugal forces on the working medium and parts in a vibration machine oscillating reservoir with an impeller. Manufacturing Technology. 2021; 21 (3):364-372.

Chicago/Turabian Style

Janos Kundrak; Andrey V. Mitsyk; Vladimir A. Fedorovich; Angelos P. Markopoulos; Anatoly I. Grabchenko. 2021. "Modeling the energy action of vibration and centrifugal forces on the working medium and parts in a vibration machine oscillating reservoir with an impeller." Manufacturing Technology 21, no. 3: 364-372.

Review
Published: 09 May 2021 in Archives of Computational Methods in Engineering
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Additive Manufacturing concentrates the attention, not only of the research and academic community, but of the industry as well. Selective Laser Melting (SLM) and Selective Laser Sintering (SLS) are among the broadest employed methods in AM, since they can treat almost all types of materials. Along with the extensive experimental research that is carried out regarding SLS and SLM, modeling and simulation are powerful tools allowing better and more in depth understanding of the processes. Nevertheless, there is no general framework in modeling, but mainly studies and proposed modeling approaches. The current paper reviews modeling methods and techniques that in literature are presented for the simulation of SLM and SLS. Besides the Finite Element Method, which is the most common method used, other numerical methods like Discrete Element Method, Smoothed Particles Hydrodynamics and Molecular Dynamics have been overviewed as well. The heat transfer and fluid dynamics models consist the main core of every simulation, while other sub-models are integrated to estimate parameters like residual stresses, part deformation, material microstructure, or crystallization. The main scope of the current paper is to provide a comprehensive and detailed review on the modeling and simulation of SLS/SLM and to inform the reader concerning the different modeling strategies.

ACS Style

Emmanouil L. Papazoglou; Nikolaos E. Karkalos; Panagiotis Karmiris-Obratański; Angelos P. Markopoulos. On the Modeling and Simulation of SLM and SLS for Metal and Polymer Powders: A Review. Archives of Computational Methods in Engineering 2021, 1 -33.

AMA Style

Emmanouil L. Papazoglou, Nikolaos E. Karkalos, Panagiotis Karmiris-Obratański, Angelos P. Markopoulos. On the Modeling and Simulation of SLM and SLS for Metal and Polymer Powders: A Review. Archives of Computational Methods in Engineering. 2021; ():1-33.

Chicago/Turabian Style

Emmanouil L. Papazoglou; Nikolaos E. Karkalos; Panagiotis Karmiris-Obratański; Angelos P. Markopoulos. 2021. "On the Modeling and Simulation of SLM and SLS for Metal and Polymer Powders: A Review." Archives of Computational Methods in Engineering , no. : 1-33.

Chapter
Published: 30 April 2021 in Introduction to Mechanical Engineering
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Electrical Discharge Machining (EDM) is a non-conventional machining process, widely utilized in the modern industrial environment, especially in applications that involve the manufacturing of complex shapes and geometries, along with high dimensional accuracy. Conceptually EDM is a simple process, which is based on the erosion that accompanies the spark occurrence between two electrically conductive materials, one that acts as working electrode and one as the workpiece. Nevertheless, in practice, and due to the technological advances in the relevant field, EDM has become a multi-parameter machining process. The current chapter aims to familiarize the reader with the process of EDM, while at the same time, to provide useful and practical information concerning more advanced topics. The chapter's first sections are an introduction to the EDM, where a brief historical review, and the basic working principles are presented. The basic physical mechanisms that take place during machining are analyzed, along with the major machining parameters and performance indexes. Moreover, a brief literature review concerning the machining of steel and aluminum alloys with EDM is quoted. Thereafter, the basic principles for modeling and simulation of the process are introduced, aiming to become a helpful reference in model development. Finally, in the last section, a comparative study regarding the machining of two different aluminum alloys (i.e., Al5052 and Al6063) with EDM is presented, indicating how different alloys of the same base may have different behavior during their machining with EDM.

ACS Style

Panagiotis Karmiris-Obratański; Emmanouil L. Papazoglou; Angelos P. Markopoulos. Modeling and Experimental Work on Electrical Discharge Machining. Introduction to Mechanical Engineering 2021, 19 -40.

AMA Style

Panagiotis Karmiris-Obratański, Emmanouil L. Papazoglou, Angelos P. Markopoulos. Modeling and Experimental Work on Electrical Discharge Machining. Introduction to Mechanical Engineering. 2021; ():19-40.

Chicago/Turabian Style

Panagiotis Karmiris-Obratański; Emmanouil L. Papazoglou; Angelos P. Markopoulos. 2021. "Modeling and Experimental Work on Electrical Discharge Machining." Introduction to Mechanical Engineering , no. : 19-40.

Journal article
Published: 26 April 2021 in Scientific Reports
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Titanium alloys, due to their unique properties, are utilized in numerous modern high-end applications. Electrical Discharge Machining (EDM) is a non-conventional machining process, commonly used in machining of hard-to-cut materials. The current paper, presents an experimental study regarding the machining of Titanium Grade2 with EDM, coupled with the development of a simulation model. The machining performance indexes of Material Removal Rate, Tool Wear Ratio, and Average White Layer Thickness were measured and calculated for different pulse-on currents and pulse-on times. Moreover, the developed model that integrates a heat transfer analysis with deformed geometry, allows to estimate the power distribution between the electrode and the workpiece, as well as the Plasma Flushing Efficiency, giving an insight view of the process. Finally, by employing the Response Surface Methodology, educed regression models that correlate the machining parameters with the corresponding results, while for all the aforementioned indexes, ANOVA was performed.

ACS Style

Emmanouil L. Papazoglou; Panagiotis Karmiris-Obratański; Beata Leszczyńska-Madej; Angelos P. Markopoulos. A study on Electrical Discharge Machining of Titanium Grade2 with experimental and theoretical analysis. Scientific Reports 2021, 11, 1 -21.

AMA Style

Emmanouil L. Papazoglou, Panagiotis Karmiris-Obratański, Beata Leszczyńska-Madej, Angelos P. Markopoulos. A study on Electrical Discharge Machining of Titanium Grade2 with experimental and theoretical analysis. Scientific Reports. 2021; 11 (1):1-21.

Chicago/Turabian Style

Emmanouil L. Papazoglou; Panagiotis Karmiris-Obratański; Beata Leszczyńska-Madej; Angelos P. Markopoulos. 2021. "A study on Electrical Discharge Machining of Titanium Grade2 with experimental and theoretical analysis." Scientific Reports 11, no. 1: 1-21.

Journal article
Published: 23 April 2021 in Russian Engineering Research
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Improvement in the manufacturing process on the basis of lean production is considered. Specifically, attention focuses on value stream maps (VSM), the Kanban system, just-in-time (JIT) production, single-minute exchange of dies (SMED), and the five-step (5S) system, as applied to the production of special-purpose clocks. Current and future value stream maps for the Chelyabinsk clock plant are created and assessed. A process for introduction of the VSM method at the plant is developed, along with the corresponding standard. The economic benefits of the research project are noted.

ACS Style

N. V. Syreyshchikova; D. Yu. Pimenov; A. P. Markopoulos; L. Moldovan. Value Stream Maps in Clock Production. Russian Engineering Research 2021, 41, 378 -381.

AMA Style

N. V. Syreyshchikova, D. Yu. Pimenov, A. P. Markopoulos, L. Moldovan. Value Stream Maps in Clock Production. Russian Engineering Research. 2021; 41 (4):378-381.

Chicago/Turabian Style

N. V. Syreyshchikova; D. Yu. Pimenov; A. P. Markopoulos; L. Moldovan. 2021. "Value Stream Maps in Clock Production." Russian Engineering Research 41, no. 4: 378-381.

Journal article
Published: 30 March 2021 in Machines
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Surface quality has always been an important goal in the manufacturing industry, as it is not only related to the achievement of appropriate geometrical tolerances but also plays an important role in the tribological behavior of the surface as well as its resistance to fatigue and corrosion. Usually, in order to achieve sufficiently high surface quality, process parameters, such as cutting speed and feed, are regulated or special types of cutting tools are used. In the present work, an alternative strategy for slot milling is adopted, namely, trochoidal milling, which employs a more complex trajectory for the cutting tool. Two series of experiments were initially conducted with traditional and trochoidal milling under various feed and cutting speed values in order to evaluate the capabilities of trochoidal milling. The findings showed a clear difference between the two milling strategies, and it was shown that the trochoidal milling strategy is able to provide superior surface quality when the appropriate process parameters are also chosen. Finally, the effect of the depth of cut, coolant and trochoidal stepover on surface roughness during trochoidal milling was also investigated, and it was found that lower depths of cut, the use of coolant and low values of trochoidal stepover can lead to a considerable decrease in surface roughness.

ACS Style

Nikolaos Karkalos; Panagiotis Karmiris-Obratański; Szymon Kurpiel; Krzysztof Zagórski; Angelos Markopoulos. Investigation on the Surface Quality Obtained during Trochoidal Milling of 6082 Aluminum Alloy. Machines 2021, 9, 75 .

AMA Style

Nikolaos Karkalos, Panagiotis Karmiris-Obratański, Szymon Kurpiel, Krzysztof Zagórski, Angelos Markopoulos. Investigation on the Surface Quality Obtained during Trochoidal Milling of 6082 Aluminum Alloy. Machines. 2021; 9 (4):75.

Chicago/Turabian Style

Nikolaos Karkalos; Panagiotis Karmiris-Obratański; Szymon Kurpiel; Krzysztof Zagórski; Angelos Markopoulos. 2021. "Investigation on the Surface Quality Obtained during Trochoidal Milling of 6082 Aluminum Alloy." Machines 9, no. 4: 75.

Editorial
Published: 08 February 2021 in Machines
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The modern, highly competitive industrial environment demands machining and production processes that result in exceptional quality and precision

ACS Style

Mariusz Deja; Angelos Markopoulos. Advances and Trends in Non-Conventional, Abrasive and Precision Machining. Machines 2021, 9, 37 .

AMA Style

Mariusz Deja, Angelos Markopoulos. Advances and Trends in Non-Conventional, Abrasive and Precision Machining. Machines. 2021; 9 (2):37.

Chicago/Turabian Style

Mariusz Deja; Angelos Markopoulos. 2021. "Advances and Trends in Non-Conventional, Abrasive and Precision Machining." Machines 9, no. 2: 37.

Journal article
Published: 29 January 2021 in Applied Sciences
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A three-dimensional, thermal-structural finite element model, originally developed for the study of laser–solid interactions and the generation and propagation of surface acoustic waves in the macroscopic level, was downscaled for the investigation of the surface roughness influence on pulsed laser–solid interactions. The dimensions of the computational domain were reduced to include the laser-heated area of interest. The initially flat surface was progressively downscaled to model the spatial roughness profile characteristics with increasing geometrical accuracy. Since we focused on the plastic and melting regimes, where structural changes occur in the submicrometer scale, the proposed downscaling approach allowed for their accurate positioning. Additionally, the multiscale simulation results were discussed in relation to experimental findings based on white light interferometry. The combination of this multiscale modeling approach with the experimental methodology presented in this study provides a multilevel scientific tool for an in-depth analysis of the influence of heat parameters on the surface roughness of solid materials and can be further extended to various laser–solid interaction applications.

ACS Style

Evaggelos Kaselouris; Kyriaki Kosma; Yannis Orphanos; Alexandros Skoulakis; Ioannis Fitilis; Angelos P. Markopoulos; Makis Bakarezos; Michael Tatarakis; Nektarios A. Papadogiannis; Vasilis Dimitriou. Downscaled Finite Element Modeling of Metal Targets for Surface Roughness Level under Pulsed Laser Irradiation. Applied Sciences 2021, 11, 1253 .

AMA Style

Evaggelos Kaselouris, Kyriaki Kosma, Yannis Orphanos, Alexandros Skoulakis, Ioannis Fitilis, Angelos P. Markopoulos, Makis Bakarezos, Michael Tatarakis, Nektarios A. Papadogiannis, Vasilis Dimitriou. Downscaled Finite Element Modeling of Metal Targets for Surface Roughness Level under Pulsed Laser Irradiation. Applied Sciences. 2021; 11 (3):1253.

Chicago/Turabian Style

Evaggelos Kaselouris; Kyriaki Kosma; Yannis Orphanos; Alexandros Skoulakis; Ioannis Fitilis; Angelos P. Markopoulos; Makis Bakarezos; Michael Tatarakis; Nektarios A. Papadogiannis; Vasilis Dimitriou. 2021. "Downscaled Finite Element Modeling of Metal Targets for Surface Roughness Level under Pulsed Laser Irradiation." Applied Sciences 11, no. 3: 1253.

Journal article
Published: 08 January 2021 in Materials
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Electrical Discharge Machining (EDM) consists of a non-conventional machining process, which is widely used in modern industry, and especially in machining hard-to-cut materials. By employing EDM, complex shapes and geometries can be produced, with high dimensional accuracy. Titanium alloys, due to their unique inherent properties, are extensively utilized in high end applications. Nevertheless, they suffer from poor machinability, and thus, EDM is commonly employed for their machining. The current study presents an experimental investigation regarding the process of Ti–6Al–4V ELI with high power EDM, using a graphite electrode. Control parameters were the pulse-on current (Ip) and time (Ton), while Machining performances were estimated in terms of Material Removal Rate (MRR), Tool Material Removal Rate (TMRR), and Tool Wear Ratio (TWR). The machined Surface Roughness was calculated according to the Ra and the Rt values, by following the ISO 25178-2 standards. Furthermore, the EDMed surfaces were observed under optical and SEM microscopy, while their cross sections were also studied in order the Average White Layer Thickness (AWLT) and the Heat Affected Zone (HAZ) to be measured. Finally, for the aforementioned indexes, Analysis Of Variance was performed, whilst for the MRR and TMRR, based on the Response Surface Method (RSM), semi-empirical correlations were presented. The scope of the current paper is, through a series of experiments and by employing statistical tools, to present how two main machining parameters, i.e., pulse-on current and time, affect major machining performance indexes and the surface roughness.

ACS Style

Panagiotis Karmiris-Obratański; Emmanouil L. Papazoglou; Beata Leszczyńska-Madej; Krzysztof Zagórski; Angelos P. Markopoulos. A Comprehensive Study on Processing Ti–6Al–4V ELI with High Power EDM. Materials 2021, 14, 303 .

AMA Style

Panagiotis Karmiris-Obratański, Emmanouil L. Papazoglou, Beata Leszczyńska-Madej, Krzysztof Zagórski, Angelos P. Markopoulos. A Comprehensive Study on Processing Ti–6Al–4V ELI with High Power EDM. Materials. 2021; 14 (2):303.

Chicago/Turabian Style

Panagiotis Karmiris-Obratański; Emmanouil L. Papazoglou; Beata Leszczyńska-Madej; Krzysztof Zagórski; Angelos P. Markopoulos. 2021. "A Comprehensive Study on Processing Ti–6Al–4V ELI with High Power EDM." Materials 14, no. 2: 303.

Journal article
Published: 01 January 2021 in Machines
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In this study, the development of a 3D Finite Element (FE) model for the turning of AISI-D3 with ceramic tooling is presented, with respect to four levels of cutting speed, feed, and depth of cut. The Taguchi method was employed in order to create the orthogonal array according to the variables involved in the study, reducing this way the number of the required simulation runs. Moreover, the possibility of developing a prediction model based on well-established statistical tools such as the Response Surface Methodology (RSM) and the Analysis of Variance (ANOVA) was examined, in order to further investigate the relationship between the cutting speed, feed, and depth of cut, as well as their influence on the produced force components. The findings of this study point out an increased correlation between the experimental results and the simulated ones, with a relative error below 10% for most tests. Similarly, the values derived from the developed statistical model indicate a strong agreement with the equivalent numerical values due to the verified adequacy of the statistical model.

ACS Style

Panagiotis Kyratsis; Anastasios Tzotzis; Angelos Markopoulos; Nikolaos Tapoglou. CAD-Based 3D-FE Modelling of AISI-D3 Turning with Ceramic Tooling. Machines 2021, 9, 4 .

AMA Style

Panagiotis Kyratsis, Anastasios Tzotzis, Angelos Markopoulos, Nikolaos Tapoglou. CAD-Based 3D-FE Modelling of AISI-D3 Turning with Ceramic Tooling. Machines. 2021; 9 (1):4.

Chicago/Turabian Style

Panagiotis Kyratsis; Anastasios Tzotzis; Angelos Markopoulos; Nikolaos Tapoglou. 2021. "CAD-Based 3D-FE Modelling of AISI-D3 Turning with Ceramic Tooling." Machines 9, no. 1: 4.

Journal article
Published: 01 January 2021 in Metals
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Abrasive waterjet cutting is a well-established non-conventional technique for the processing of difficult-to-cut material and rendering of various complex geometries with high accuracy. However, as in every machining process, it is also required that high efficiency and productivity are achieved. For that reason, in the present study, the effect of performing the machining process by multiple passes is investigated, and the evaluation of this approach is performed in terms of total depth of penetration, kerf width, kerf taper angle, mean material removal rate, and cutting efficiency. In the case of multiple passes, the passes are performed in the same direction with the traverse speed adjusted accordingly in order to maintain the total machining time constant in each case. From the experimental results, it was found that the effect of multiple passes on the kerf characteristics, mean material removal rate, and cutting efficiency depends on the process conditions, especially regarding the depth of penetration, and it is possible to achieve significantly higher efficiency by the multi-pass cutting technique when the appropriate process conditions are selected.

ACS Style

Panagiotis Karmiris-Obratański; Nikolaos E. Karkalos; Rafał Kudelski; Emmanouil L. Papazoglou; Angelos P. Markopoulos. On the Effect of Multiple Passes on Kerf Characteristics and Efficiency of Abrasive Waterjet Cutting. Metals 2021, 11, 74 .

AMA Style

Panagiotis Karmiris-Obratański, Nikolaos E. Karkalos, Rafał Kudelski, Emmanouil L. Papazoglou, Angelos P. Markopoulos. On the Effect of Multiple Passes on Kerf Characteristics and Efficiency of Abrasive Waterjet Cutting. Metals. 2021; 11 (1):74.

Chicago/Turabian Style

Panagiotis Karmiris-Obratański; Nikolaos E. Karkalos; Rafał Kudelski; Emmanouil L. Papazoglou; Angelos P. Markopoulos. 2021. "On the Effect of Multiple Passes on Kerf Characteristics and Efficiency of Abrasive Waterjet Cutting." Metals 11, no. 1: 74.

Journal article
Published: 07 December 2020 in Metals
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The hardened tool steel AISI O1 has increased strength, hardness, and wear resistance, which affects the complexity of the machining process. AISI O1 has also been classified as difficult to cut material hence optimum cutting parameters are required for the sustainable machining of the alloy. In this work, the effect of feed peer tooth (fz), cutting speed (vc), cutting of depth (ap) on surface roughness (Ra, Rt), cutting force (Fx, Fy), cutting power (Pc), machining cost (Ci), and carbon dioxide (Ene) were investigated during the slot milling process of AISI O1 hardened steel. A regression analysis was carried out on the obtained experimental results and the induction of nonlinear mathematical equations of surface roughness, cutting force, cutting power, and machining cost with a high coefficient of determination (R2 = 90.62–98.74%) were deduced. A sustainability assessment model is obtained for optimal and stable levels of design variables when slot milling AISI O1 tool steel. Stable indicators to ensure personal health and safety of operation, P1 values were set to “1” at a cutting speed of 20 m/min or 43.3 m/min and “2” at a cutting speed of 66.7 m/min or 90 m/min. It is revealed that for eco-benign machining of AISI O1, the optimum parameters of 0.01 mm/tooth, 20 m/min, and 0.1 mm should be adopted for feed rate, cutting speed, and depth of cut respectively.

ACS Style

Angelos P. Markopoulos; Nikolaos E. Karkalos; Mozammel Mia; Danil Yurievich Pimenov; Munish Kumar Gupta; Hussein Hegab; Navneet Khanna; Vincent Aizebeoje Balogun; Shubham Sharma. Sustainability Assessment, Investigations, and Modelling of Slot Milling Characteristics in Eco-Benign Machining of Hardened Steel. Metals 2020, 10, 1650 .

AMA Style

Angelos P. Markopoulos, Nikolaos E. Karkalos, Mozammel Mia, Danil Yurievich Pimenov, Munish Kumar Gupta, Hussein Hegab, Navneet Khanna, Vincent Aizebeoje Balogun, Shubham Sharma. Sustainability Assessment, Investigations, and Modelling of Slot Milling Characteristics in Eco-Benign Machining of Hardened Steel. Metals. 2020; 10 (12):1650.

Chicago/Turabian Style

Angelos P. Markopoulos; Nikolaos E. Karkalos; Mozammel Mia; Danil Yurievich Pimenov; Munish Kumar Gupta; Hussein Hegab; Navneet Khanna; Vincent Aizebeoje Balogun; Shubham Sharma. 2020. "Sustainability Assessment, Investigations, and Modelling of Slot Milling Characteristics in Eco-Benign Machining of Hardened Steel." Metals 10, no. 12: 1650.

Journal article
Published: 19 November 2020 in Procedia Manufacturing
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Non-conventional manufacturing processes are often advantageous compared to conventional ones, as they can achieve high productivity in demanding cases. Abrasive waterjet (AWJ) machining is one of the most established non-conventional machining processes, which can achieve high material removal rates without leading to undesired workpiece material alterations and can render a large variety of shapes. In the present work, experiments regarding the AWJ milling of high strength 7075-T6 aluminum alloy are conducted with a view to correlate the process parameters, such as waterjet pressure, jet standoff distance, jet traverse speed and abrasive mass flow rate with depth of penetration, width and taper angle of the produced kerf. After the correlation between input and output parameters of the process is established, statistical analysis enables the determination of the influence of input parameters on output quantities and finally, appropriate process conditions for the regulation of depth of cut and kerf characteristics are derived.

ACS Style

Panagiotis Karmiris-Obratański; Rafał Kudelski; Nikolaos E. Karkalos; Angelos P. Markopoulos. Determination of the Correlation between Process Parameters and Kerf Characteristics in Abrasive Waterjet Milling of High Strength 7075-T6 Aluminum Alloy. Procedia Manufacturing 2020, 51, 812 -817.

AMA Style

Panagiotis Karmiris-Obratański, Rafał Kudelski, Nikolaos E. Karkalos, Angelos P. Markopoulos. Determination of the Correlation between Process Parameters and Kerf Characteristics in Abrasive Waterjet Milling of High Strength 7075-T6 Aluminum Alloy. Procedia Manufacturing. 2020; 51 ():812-817.

Chicago/Turabian Style

Panagiotis Karmiris-Obratański; Rafał Kudelski; Nikolaos E. Karkalos; Angelos P. Markopoulos. 2020. "Determination of the Correlation between Process Parameters and Kerf Characteristics in Abrasive Waterjet Milling of High Strength 7075-T6 Aluminum Alloy." Procedia Manufacturing 51, no. : 812-817.

Original article
Published: 04 November 2020 in The International Journal of Advanced Manufacturing Technology
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Selective laser melting (SLM) has emerged as one of the leading additive manufacturing (AM) processes for the fabrication of complex metallic components, due to its capability to achieve high quality at acceptable times. However, due to the complexity of physical phenomena occurring during SLM, such as heat transfer and phase transformations, laser absorption, molten metal flow, and moving interfaces, it is still necessary to conduct research in order to achieve a deeper understanding of the process and improve it. In the present work, a comprehensive simulation model for the study of conduction mode single-track SLM process of 316L stainless steel is presented. This model incorporates temperature and phase-dependent material properties for both powder bed and substrate, detailed calculation of the absorption coefficient, and temperature-dependent boundary conditions. The simulation results are in excellent agreement with experimental findings, regarding the morphology and dimensions of melt pool under various process conditions. Moreover, with the proposed model, analysis of power losses as well as cooling and heating rates is conducted, identifying the characteristics of SLM process and providing valuable insights for its optimization.

ACS Style

E. L. Papazoglou; N. E. Karkalos; A. P. Markopoulos. A comprehensive study on thermal modeling of SLM process under conduction mode using FEM. The International Journal of Advanced Manufacturing Technology 2020, 111, 2939 -2955.

AMA Style

E. L. Papazoglou, N. E. Karkalos, A. P. Markopoulos. A comprehensive study on thermal modeling of SLM process under conduction mode using FEM. The International Journal of Advanced Manufacturing Technology. 2020; 111 (9):2939-2955.

Chicago/Turabian Style

E. L. Papazoglou; N. E. Karkalos; A. P. Markopoulos. 2020. "A comprehensive study on thermal modeling of SLM process under conduction mode using FEM." The International Journal of Advanced Manufacturing Technology 111, no. 9: 2939-2955.

Conference paper
Published: 26 October 2020 in Recent Advances in Computational Mechanics and Simulations
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The use of ultrasonic vibrations during grinding can lead to favorable results, such as easier processing of difficult-to-cut materials, improved surface quality, reduced workpiece damage and cutting forces. In order to investigate the efficiency of this technique to nanometric grinding, simulations are essential to be initially conducted. Thus, in the present work, a Molecular Dynamics model of vibration-assisted nano-grinding is introduced, with a view to determine the efficiency of this process under various conditions, by comparing its outcome to that of a conventional nano-grinding process via analyzing grinding forces, temperatures and subsurface damage of the workpiece.

ACS Style

Nikolaos E. Karkalos; Angelos P. Markopoulos; János Kundrák. Investigation of the Efficiency of Vibration-Assisted Nano-Grinding with Molecular Dynamics. Recent Advances in Computational Mechanics and Simulations 2020, 736 -747.

AMA Style

Nikolaos E. Karkalos, Angelos P. Markopoulos, János Kundrák. Investigation of the Efficiency of Vibration-Assisted Nano-Grinding with Molecular Dynamics. Recent Advances in Computational Mechanics and Simulations. 2020; ():736-747.

Chicago/Turabian Style

Nikolaos E. Karkalos; Angelos P. Markopoulos; János Kundrák. 2020. "Investigation of the Efficiency of Vibration-Assisted Nano-Grinding with Molecular Dynamics." Recent Advances in Computational Mechanics and Simulations , no. : 736-747.

Original article
Published: 08 October 2020 in The International Journal of Advanced Manufacturing Technology
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Electrical discharge machining (EDM) is a non-conventional machining process, extensively applicable in the modern industry. Owing the non-contact nature of the process, any electrical conductive material can be machined in high quality, regardless its mechanical properties. Titanium alloys are commonly machined by EDM, as difficulties related with their low thermal conductivity and the high chemical reactivity can be overcome. As titanium alloys are utilized in quality demanding applications and industries, high machined surface quality is required, as well surface integrity. The current study presents an experimental investigation of how ED machining parameters affect the MRR, the TWR, and the SQ on machining Titanium Grade 2 by EDM. For pulse current 9/13/17/25A, and pulse on time 25/50/100/200 μs, a full-scale experiment has been carried out, using graphite electrode. The surface texture (ST) has been estimated in terms of arithmetic mean height (Sa), maximum height of scale-limited surface (Sz), and skewness of the scale-limited surface (Ssk), while also measurements of the surface waviness were conducted as well. For all the aforementioned parameters an analysis of variance (ANOVA) has been performed. Finally, the surface topography and integrity were evaluated through optical and SEM microscopy observation, through which the surface cracks and micro-cracks due to high pressure and temperature gradients can be distinguished and characterized.

ACS Style

P. Karmiris-Obratański; K. Zagórski; E. L. Papazoglou; A. P. Markopoulos. Surface texture and integrity of electrical discharged machined titanium alloy. The International Journal of Advanced Manufacturing Technology 2020, 1 -15.

AMA Style

P. Karmiris-Obratański, K. Zagórski, E. L. Papazoglou, A. P. Markopoulos. Surface texture and integrity of electrical discharged machined titanium alloy. The International Journal of Advanced Manufacturing Technology. 2020; ():1-15.

Chicago/Turabian Style

P. Karmiris-Obratański; K. Zagórski; E. L. Papazoglou; A. P. Markopoulos. 2020. "Surface texture and integrity of electrical discharged machined titanium alloy." The International Journal of Advanced Manufacturing Technology , no. : 1-15.