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Dynamic Control of Discharge Energy During WEDM for the Purpose of Eliminating Vibrations of the Wire Tool Electrode

Dynamic Control of Discharge Energy During WEDM for the Purpose of Eliminating Vibrations of the... Production in all industry fields is currently affected by new scientific and technical knowledge and the require- ments for its rapid deployment. In many cases, the most modern and highly sophisticated technical systems are applied. Simultaneously, fully automated production systems are rather successfully used and progressive pro- duction technologies are implemented. In most cases, there is an integral part of a management system that operates the challenging technological processes. These processes would not be executable without the system's precise control, which provides a suitable precondition for ensuring the high quality of manufactured products. However, the customer's demanding requirements are not always met. These involve increased requests for the quality of the final product due to the reduction of the tolerance band and application of high-strength materials. This paper aims to describe one of the solutions by which it is possible to achieve a higher quality of the machined surface after wire electrical discharge machining (WEDM). The solution proposes that through dynamic manage- ment, the WEDM process eliminates the vibrations of the wire tool electrode and thereby achieves a substantial increase in the quality of the eroded area in terms of its geometric accuracy. With the support of an extensive database of information with precise exchange of information, the proposed system will allow to control the elec- tro discharge process with regard to the optimal way of operation of the electro discharge machine on the basis of individually selected conditions. Key words: acoustic emission, dynamic control, Main Technological Parameters (MTP), Wire Electrical Discharge Machining (WEDM), Wire Tool Electrode (WTE) INTRODUCTION is characterized by a high quality of the machined surface, Modern engineering production, which uses special even the smallest deviation from the required dimension methods and technical equipment for machining high- or shape has a significant impact on the final quality of the strength materials, is characterized by high-quality prod- finished product 5, 23. One of the causes of this poor ucts. The attention is focused on such machining pro- quality is the vibration of the wire tool electrode. Alt- cesses, in which the mechanical properties of a commod- hough many experimental studies have been carried out ity and a tool have no limits 2. This mainly concerns the in this particular field, the most satisfying results have not machining manners where the material's degree of ma- been delivered yet. The experiments showed that the chinability is determined solely by its physical properties, wire tool electrode (WTE) vibrations vastly affect the geo- such as thermal and electrical conductivity, melting point metrical deviation of the eroded area 9, 11. Numerous 22, atomic valence, etc. Despite the use of these highly experiments also demonstrated that one of the main rea- sophisticated technologies, the customer's requirements sons for the WTE vibrations is the application of an im- for quality are not always met in terms of dimensional and proper WTE tensioning force. Furthermore, they found out that the magnitude of the WTE tensioning force geometric accuracy 3. These shortcomings are due to should be close to the critical values. This leads to a sub- the unsatisfactory design accuracy of the machine tool, an inadequate setting of the main and the managing techno- stantial reduction in the oscillation amplitude of the wire logical parameters, or the poor software control of the tool electrode during WEDM, resulting in a serious im- provement of the quality of the eroded surface in terms cutting process 4. Electrical discharge machining devices of geometric accuracy. In this regard, it is important to are especially prone to these types of faults. Since WEDM Ľ. STRAKA, P. KUCHTA – Dynamic Control of Discharge Energy During WEDM… 261 state that the WTE tensioning force can only be increased of electrical impulses in electro-erosive processes, the cri- up to a certain point. If the strength of the wire material terion for the minimization of WTE vibrations is absent. Therefore, our research aimed to design an algorithm for is exceeded, it will rupture 17. That could, in turn, lead the control of dynamic discharge energy during WEDM to an extension of the total machining time and thus to an that would minimize WTE vibrations. In terms of geomet- unpleasant effect on the overall WEDM productivity. Mul- tiple input factors influence the geometrical accuracy of ric accuracy, this should significantly contribute to in- creasing the final quality of the products, which are man- the eroded area 6, 10. In many cases, we cannot exactly ufactured using progressive WEDM technology. identify the principal originators of these geometrical er- rors. Mostly there are only conjectures and speculations. MATERIAL AND WORKING METHODS However, one thing is known for certain. All of these input Selection of a suitable measurement method for WTE vi- factors have a mutual denominator, and that is the preci- brations identification during WEDM sion of the WTE management, which is mainly affected by The inaccuracy of the WTE wiring due to its deflection hardware accuracy and software precision of wire move- from the straight position is caused by forces that arise as ment control 18-20. No less important is the setting of a result of the cyclic action of electric discharges during the main technological parameters (MTP), which are both the electro-erosive discharge process. In general, it can be primarily and secondarily involved in WTE vibrations, assumed that the greater the thickness of the machined which subsequently causes geometric inaccuracy of the material, the greater the deflection of the WTE. During eroded surface. Therefore, the experimental research the electro-erosive process, the thin WTE standardly os- aimed to identify the principal cause of these WTE vibra- cillates in the direction of the X and Y axes. The magnitude tions in order to design a fitting solution for their elimina- of its vibrations is directly dependent on the intensity of tion. generated electrical pulses. Fig. 1 shows the oscillation di- erosive process. rection of WTE during the electro-erosive process. LITERATURE REVIEW It is essential to focus on the originator of WTE vib rations if we want to find proper solutions to eliminate them. Based on a literary resources analysis, discharge energy was considered to be the primary causer. The energy is produced by an electric impulse generator. Nowadays, electro-erosive machining uses various types of these electric impulse generators. Most of them control the per- formance parameters to maximize cutting power. This new type of electric impulse generator that is applicable in the conditions of the electro-erosive process is de- scribed by the authors Qudeiri, J.E.A. et al. 15. However, the main deficiency of this electric impulse generator is the absence of an algorithm that would take into account the minimization of WTE vibrations. A different point of view on this issue was presented by researchers Yan, M.T. et al. 27. Their research concentrated on the develop- ment of a new type of impulse generator. This impulse generator differs from the standard types mainly in its a) roughing (fullcut) b) finishing (overcut) control algorithm, which not only maximizes EDM power Fig. 1 The direction of oscillation of the wire tool electrode dur- ing WEDM but also includes an algorithm that minimizes the rough- Source: 21. ness of the eroded surface. A similar type of electric im- pulse generator is also described by the authors Świercz, The oscillation character of the WTE differs depending on D.O. et al. 24. Nevertheless, in both cases, there is no whether a full cut or an offset cut is performed. If a rough- criterion in the control algorithm of the impulse generator ing operation is performed by a full cut, the WTE oscilla- for minimizing errors in the geometric accuracy of the tion will be executed as is shown in Fig. 1a. Fig. 1b shows eroded surface by eliminating WTE vibrations. A special the oscillation during the finishing process, when the WTE type of generator was also in a developing process carried performs an overcut. Partial compensation for these ad- out by Barik, S.K. et al. 1. Their electric impulse genera- verse effects can be achieved by applying special tor allows a power adjustment according to special quality measures. This is, in particular, a measure that includes requirements of the eroded area, but again lacks the pos- the counter-force in combination with a system that en- sibility of eliminating WTE vibrations. Another significant sures optimal WTE tension. Usually, tension force Fw for disadvantage of this generator is that it allows its applica- -2 the WTE with material strength up to 2000 N·mm ranges tion only in laboratory conditions. Based on the con- between 5 to 25 N. Its intensity is also primarily chosen ducted analysis in the field of development of electric im- concerning the diameter and material properties of the pulse generators, we concluded that in the control algo- WTE. Further reduction of WTE vibrations in this regard rithms of the ordinarily used systems for the generation 262 Management Systems in Production Engineering 2021, Volume 29, Issue 4 cannot be expected since, during WEDM, this force is gen- A portable digital laser measuring device PDV 100 Porta- erally chosen in the span of its limit values. However, ble Digital Vibrometer, used in the experimental measure- there is a potential for the elimination of WTE vibrations ment of WTE vibrations, can measure vibration velocities by modifying the concept of electric discharges. Neverthe- in the range from 0.5 Hz to 22 kHz. Thanks to its analog less, we must emphasize that this is a significant interven- and digital outputs, it provides digital processing of the tion in the traditional management system of generated measured signal, which can be transferred to a PC for sub- electrical impulses during the electro-erosive process. It is sequent analysis. necessary to look for such ways to eliminate WTE vibra- tions so that they do not negatively affect the perfor- Analysis of recorded WTE vibration values during WEDM mance of the electro-erosive process. On the contrary, it Based on the results of several experimental pieces of re- would be advantageous if by shortening the total machin- search in the field, it has been shown that the WTE vibra- ing time it could increase the economic efficiency 14. tions in the direction of the X-axis acquire slightly higher These goals can only be achieved with the collaboration values than the vibrations in the direction of the Y-axis. In terms of consequences, it can be clearly stated that the of highly sophisticated online monitoring and dynamic WTE vibrations in the X-axis direction have a significantly control systems. Currently, the information used to con- trol the electro-erosive process is derived from the actual smaller effect on the occurrence of the geometric inaccu- value parameters of electric discharge. The magnitude of racy of a machined surface because they are generated in the WTE tension, discharge current I, voltage U, working its feed direction. The problem, however, is the vibrations that are generated transversely to the WTE feed direction, gap, and others are monitored from these parameters 7, that is in the direction of the Y-axis. The magnitude of the 25. Yet, the current setting of the values of these param- critical oscillation frequency not only depends on the elec- eters does not take into account all the phenomena that tric discharge parameters, but also on other parameters occur at the place of electric discharge 13, 26. Therefore, such as the thickness of the machined material, the diam- it is crucial to include the phenomena related to WTE vi- eter of the wire electrode, its tensile force, and many oth- brations in the control algorithm as well. ers. Therefore, this critical frequency cannot be implicitly determined. The only possibility for its identification is the Identification of WTE vibrations during WEDM application of one of the measuring methods. Fig. 3 shows There are two basic approaches to identifying vibrations the maximum WTE oscillation amplitude depending on its in practice – direct and indirect. Although the direct meas- frequency, which occurs due to electric discharges gener- urement of the magnitude of the WTE vibrations is slightly ated during WEDM. more precise compared to the indirect one, in real-life conditions of an electro discharge machine, this method results in a large number of problems. The main issue con- cerns the location of sensors. The accuracy of the indirect method of measuring the magnitude of the WTE vibration is, in turn, affected by interferences, which to some extent distort the results of the measurements. When applying individual measuring methods, the right choice of the measuring technique is crucial. Consequently, for the ini- tial identification of the WTE vibrations in the experi- a) roughing cut mental research, a direct measuring method was applied using a laser measuring device PDV 100 Portable Digital Vibrometer. The course of measurement of the WTE vi- bration during WEDM is shown in Fig. 2. b) finishing cut (overcut) Fig. 3 Dependence of the oscillation amplitude of the wire tool electrode on the oscillation frequency of the WTE generated by the influence of electric discharges during WEDM Based on the performed experimental measurements, it was also shown that the magnitude of the oscillation am- plitude of the WTE is not directly proportional to its oscil- lation frequency. As can be observed from the graph in Fig. 3, its maximum value was reached by applying the Fig. 2 Application of the direct measuring method of WTE critical frequency of the WTE oscillation, generated by the vibrations during WEDM influence of electric discharges during WEDM. At the Ľ. STRAKA, P. KUCHTA – Dynamic Control of Discharge Energy During WEDM… 263 same time, its value varies not only depending on the the application of optimization techniques based on pro- thickness of the machined material or the properties of cess algorithms. The use of such algorithms, which guar- the WTE, but also on the machining method itself. antee high convergence in the process of optimum iden- tification, is particularly suitable [28]. To ensure the ideal Design of an algorithm for dynamic control of discharge functionality of the control system of the generated elec- energy during WEDM trical pulses, a mechanism enabling the required choice of Even though there is now an increasing emphasis on the the optimization criterion must also be implemented in complexity of knowing the set of individual characteristics the system. of electric discharges during WEDM, comprehensive iden- This means that in real action, the possibility of choosing tification of their interrelationships is still lacking. Also, an optimization criterion would be primarily focused on there are no proposals to minimize the adverse effect of achieving high quality of the machined surface, high electric discharges on the quality of the machined surface productivity of the electro-erosive process, high efficiency after WEDM in terms of the achieved geometric accuracy. of the electro-erosive process, or a combination thereof. A certain solution to this problem is to design a dynamic This requires an expert system based on an extensive in- control of the discharge energy of electrical impulses dur- formation database. Its proper connection with the con- ing WEDM. Its goal is to eliminate WTE vibrations, which trol system of the electro-erosive machine would thus en- will improve the geometric accuracy of the eroded sur- able efficient operation not only in serial but also in piece face. However, this requires a precise design of the con- production. trol algorithm. The practical advantage of the proposed Design of a system for dynamic control of discharge en- algorithm would also be to include optimization mathe- ergy during WEDM in a real electro-erosive machine con- matical models that, based on input parameters related ditions to material and dimensional properties of the workpiece Regarding the use of machining processes with a non-sta- and wire tool electrode, allow automatic adjustment of tionary character, which also includes electro-erosive ma- MTP for the required quality of the eroded surface in chining; highly reliable control systems are required to terms of its parameters of roughness. control the discharge energy. These systems are supposed Most importantly, a correct design of the measuring chain to effectively determine the optimal parameters of the is necessary when designing an algorithm for dynamic electro-erosive process with respect to the demanded control of discharge energy during WEDM in order to quality of the machined surface. The design of such a eliminate WTE vibrations. It is inevitable to define the sen- management system should implement the principles of sors that will transmit the recorded signal to the control self-organization using advanced methods and highly so- system of the electric pulse generator and the control sys- phisticated technical means. The following Fig. 5 demon- tem of the electro-erosive machine. Using the transmitted strates a schematic diagram of the connection of the AE input information, they will adjust the parameters of the sensors with the dynamic control system of the EDM ma- electric discharge so as to reduce the oscillation frequency chine, which will enable the elimination of undesired WTE of the WTE. The following Fig. 4 shows a design of a con- vibrations during WEDM. trol algorithm for dynamic control of discharge energy during WEDM, the task of which is to minimize the vibra- tions of the WTE in order to achieve a higher quality of the eroded surface in terms of its geometric accuracy. Fig. 5 Diagram of dynamic control of generated discharge en- ergy during WEDM A major problem with the direct method of measuring WTE vibrations during WEDM is the setting up of sensors. These would always have to be re-established for each specific Fig. 4 Algorithm for dynamic discharge energy control during condition of the machining process, which is unacceptable WEDM from a practical point of view. Therefore, despite the above-mentioned negative aspects of the indirect method A characteristic feature of the proposed system for dy- of measuring WTE vibrations during the electro-erosive namic control of discharge energy during WEDM is also process, acoustic emission (AE) sensors based on this 264 Management Systems in Production Engineering 2021, Volume 29, Issue 4 method have been implemented in the proposed system. certain combination of several factors creates the maxi- An overlap of electromagnetic interference (EMI) with the mum oscillation amplitude of WTE. Yet, this frequency is scanned AE signals might be a risk in this method of indirect constantly changing according to special conditions. There- WTE vibration measurement. However, it is possible to fil- fore, it was necessary to focus on a solution that can dy- ter this interfering element by a suitable intervention. namically respond to the change. One of the acceptable Providing there is a large thickness of the machined mate- ways to identify ever-changing WTE vibrations has been the rial or some specific values of the setting of the parameters indirect method of AE sensing. As the problem-solving re- of the electric discharge, there might be a slight increase in sult was considered to be the inclusion of the WTE vibra- the amplitude of the oscillation of the WTE at one of its tions parameter in the control algorithm as another param- ends. Accordingly, it seemed advantageous to place the AE eter within the monitored parameters of the electro dis- sensors on both the top and bottom of the WTE line. The charge process. This input parameter in the process of con- recorded values could be distorted if the AE sensor is placed trolling the generated electric discharges has made it pos- on only one of the lines. The signals received from the AE sible to acquire a new dimension in the field of increasing sensors will be transmitted to the A/D converter. Subse- the final quality of products produced by progressive elec- quently, the filtered and modified information will be im- tro-erosive technology. Additionally, by monitoring a given ported into the control system of the electro-erosive ma- process parameter, it is possible to achieve a substantial in- chine. Based on this input data, the machine will adjust the crease in the level of intelligent dynamic control of the elec- electric discharge parameters to increase or decrease the tro-erosive process. It can also detect and subsequently, by frequency, thereby minimizing the side effect of the maxi- a suitable modification of the generated electrical pulses mum oscillation amplitude of the WTE. eliminate the occurrence of undesired electrical discharges, which increase the amplitude of the oscillation of the wire DISCUSSION electrode. This information is valuable because it allows the Commonly used electro-erosive devices allow the genera- application of an advanced electric discharge control strat- tion of electric discharges only on the basis of current con- egy, thus eliminating the adverse impact of improper MTP ditions in the working gap. Their control system adjusts the selection. Overall, the result is not only an increase in the power characteristics of the pulse generator based on the final quality of products and ensuring the stability of the dis- measurement of the values of electric voltage and current charge process, but ultimately also an increase in the total in the working gap according to predetermined reference WEDM productivity. values acquired from the compiled control algorithms. However, in order to meet the demanding requirements ACKNOWLEDGMENTS for the quality of the machined surface in terms of its geo- The authors would like to thank the grant agency for sup- metric accuracy, monitoring of only the mentioned param- porting research work the project VEGA 1/0205/19. eters is insufficient [8]. Nevertheless, these demanding re- quirements for product quality can be met by integrating REFERENCES [1] S.K. Barik and P.S. Rao. “Design of Pulse Circuit of EDM Die- the most modern technologies for monitoring and dynamic sinker.” International Research Journal of Engineering and control of the electro-erosive process [12, 16]. This will sig- Technology, vol. 3(5), pp. 2762-2765, 2016. nificantly increase not only its stability and cutting perfor- [2] F. Botko, M. Hatala, P. Beraxa, J. Duplák and J. Zajac. “De- mance but also the final quality of products produced by termination of CVD coating thickness for shaped surface progressive WEDM technology. Concurrently, it can be tool.” TEM Journal, vol. 7(2), pp. 428-432, 2018. stated that the application of a dynamic control system of [3] R. Davis, A. Singh, S. Kachhap and N. Nath. “A comparative generated electrical impulses during WEDM based on input study of EDD and PM-EDD in producing holes in inconel information from the field of electric discharge is an effec- 718 alloy.” Key Engineering Materials, vol. 833, pp. 48-53, tive means of eliminating WTE vibrations. A characteristic 2020. [4] E. Evin, M. Tomáš and J. Kmec. “Optimization of electro- feature of the proposed dynamic system for controlling the discharge texturing parameters for steel sheets' finishing generated discharge energy during WEDM is also its flexi- rollers.” Materials, vol. 13(5), art. no. 1223, 2020. bility and openness to real-life conditions. Based on an ex- [5] S. Hamed, L.A. Al-Juboori, V.N. Najm and A.M. Saleh. “Ana- tensive database of information, as well as the fast and ac- lysis the impact of WEDM parameters on surface curate exchange of information with the external environ- microstructure using response surface methodology.” A- ment, the system will allow a controlling of the electro-ero- SET 2020, Advances in Science and Engineering Technology sive process with respect to the optimal way of operation International Conferences, Dubai, 4-9 February 2020, art of the electro-erosive machine according to the individually no. 9118208, 2020. selected optimization criteria. [6] S. Hašová and Ľ. Straka. “Design and verification of soft- ware for simulation of selected quality indicators of machi- ned surface after WEDM.” Academic Journal of Manufac- CONCLUSION turing Engineering, vol. 14(2), pp. 13-20, 2016. The results of several studies demonstrate that the geo- [7] E. Kuznetsov, V. Nahornyi and T. Krenicky. “Gas Flow Simu- metric deviations of the eroded surface are mainly caused lation in the Working Gap of Impulse Gas-barrier Face by WTE vibrations. Therefore, it was crucial to find an ac- Seal.” Management Systems in Production Engineering, ceptable solution to eliminate them. Based on the out- vol. 28(4), pp. 298-303, 2020. comes of experimental research, it has been shown that a Ľ. STRAKA, P. KUCHTA – Dynamic Control of Discharge Energy During WEDM… 265 [8] J. Maščenik. “Implementation of the designed program for [18] Ľ. Straka and G. Dittrich. “Influence of tool steel properties calculation and check of chain gears.” MM Science Journal, on surface quality after electrical discharge machining by vol. 2019 (december), pp. 3431-3434, 2019. wire electrode.” The International Journal of Advanced [9] K. Mouralova, L. Benes, J. Bednar, R. Zahradnicek, T. Pro- Manufacturing Technology, vol. 106(5-6), pp. 1617-1632, kes and J. Fries. “Analysis of machinability and crack occur- 2020. rence of steels 1.2363 and 1.2343ESR machined by die-sin- [19] Ľ. Straka, I. Čorný, J. Piteľ and S. Hašová. “Statistical Ap- king EDM.” Coatings, vol. 10(4), art. no. 406, 2020. proach to Optimize the Process Parameters of HAZ of Tool [10] V. Ngocpi, D.T. Tam, N.M. Cuong and T.H. Tran. “Multi-ob- Steel EN X32CrMoV12-28 after Die-Sinking EDM with SF- jective optimization of PMEDM process parameters for Cu Electrode.” Metals, vol. 7(2), pp. 1-22, 2017. processing cylindrical shaped parts using taguchi method [20] Ľ. Straka and S. Hašová. “The critical failure determination and grey relational analysis.” International Journal of Me- of the constructional parts of autonomous electroerosion chanical and Production Engineering Research and Develo- equipment by applying Boolean logic. ”Academic Journal pment, vol. 10(2), pp. 669-678, 2020. of Manufacturing Engineering, vol. 14(2), pp. 80-86, 2016. [11] Š. Olejarova and T. Krenicky. “Monitoring the condition of [21] Ľ. Straka and G. Dittrich. “Intelligent control system of ge- the spindle of the milling machine using vibration.” MM nerated electrical pulses at discharge machining.” Science Journal, vol. 2016(11), pp. 1227-1231, 2016. Emerging trends in mechatronics, IntechOpen, 26 p., 2020. [12] A. Panda, Š. Olejárová, J. Valíček and M. Harničárová.” Mo- [22] L. Sukhodub, A. Panda, K. Dyadyura, I. Pandová and T. Kre- nitoring of the condition of turning machine bearing hou- nický. “The design criteria for biodegradable magnesium sing through vibrations.” The International Journal of Ad- alloy implants.” MM Science Journal, vol. 2018(Decem- vanced Manufacturing Technology, vol. 97(1-4), pp. 401- ber), pp. 2673-2679, 2018. 411, 2018. [23] D. Oniszczuk-Swiercz, R. Swiercz, T. Chmielewski and T. Sa- [13] A. Panda, V. Nahornyi, I. Pandová, M. Harničárová, M. lacinski. “Experimental investigation of influence WEDM Kušnerová, J. Valíček and J. Kmec. “Development of the parameters on surface roughness and flatness deviation.” method for predicting the resource of mechanical sys- Metal 2020, vol. 29, p. 611-617, 2020. tems.” The International Journal of Advanced Manufac- [24] D.O. Świercz and R. Świercz. “EDM – analyses of current turing Technology, vol. 105(1-4), pp. 1563-1571, 2019. and voltage waveforms.” Mechanik, vol. 2, pp. 1-3, 2017. [14] M. Pollák and J. Tkáč. “Enterprise information data ma- [25] R. Swiercz, and R. Holubek. “Experimental investigation of nagement system for small manufacturing company.” TEM influence electrical discharge energy on the surface layer Journal – Technology, Education, Management, Informa- properties after EDM.” Welding Technology Review, vol. tics, vol. 8(4), pp. 1169-1175, 2019. 92(5), pp. 7-13, 2020. [15] J.E.A. Qudeiri, A. Saleh, A. Ziout, A.H.I. Mourad, M.H. Abidi [26] J. Wang, J.A. Sánchez, B. Izquierdo and I. Ayesta. “Experi- and A. Elkaseer. “Advanced Electric Discharge Machining mental and numerical study of crater volume in wire of Stainless Steels: Assessment of the State of the Art, electrical discharge machining.” Materials, vol. 13(3), art. Gaps and Future Prospect.” Materials, vol. 2019(12), a.no. no. 577, 2020. 907, 2019. [27] M.T. Yan and T.Ch. Lin. “Development of a Pulse Generator [16] M. Rimár, M. Fedák, A. Kulikov and P. Šmeringai. “Study of for Rough Cutting of Oil-based Micro Wire-EDM.” ISEM gaseous flows in closed area with forced ventilation.” MM XVIII, Procedia CIRP, vol. 42, pp. 709-714, 2016. Science Journal, vol. 2018(3), pp. 2188-2191, 2018. [28] D. Zhou, Ch. Sun, Y. Zhang and P. Wang. “A noncontact full- [17] P. Shandilya, P.K. Jain and N.K. Jain. “Modelling and pro- field flatness measuring system based on fringe projec- cess optimisation for wire electric discharge machining of tion.” Proceedings of SPIE, vol. 11439, art.no. 114391B, metal matrix composites.” International Journal of Machi- 2020. ning and Machinability of Materials, vol. 18, pp. 119-1207, Ľuboslav Straka ORCID ID: 0000-0003-0914-2155 Technical University of Kosice with a seat in Prešov Faculty of Manufacturing Technologies Department of Automotive and Manufacturing Technologies Štúrova 31, Prešov, Slovakia e-mail: luboslav.straka@tuke.sk, Patrik Kuchta Technical University of Kosice with a seat in Prešov Faculty of Manufacturing Technologies Department of Automotive and Manufacturing Technologies Štúrova 31, Prešov, Slovakia e-mail: patrik.kuchta@tuke.sk http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Management Systems in Production Engineering de Gruyter

Dynamic Control of Discharge Energy During WEDM for the Purpose of Eliminating Vibrations of the Wire Tool Electrode

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de Gruyter
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© 2021 Ľuboslav Straka et al., published by Sciendo
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2450-5781
DOI
10.2478/mspe-2021-0032
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Abstract

Production in all industry fields is currently affected by new scientific and technical knowledge and the require- ments for its rapid deployment. In many cases, the most modern and highly sophisticated technical systems are applied. Simultaneously, fully automated production systems are rather successfully used and progressive pro- duction technologies are implemented. In most cases, there is an integral part of a management system that operates the challenging technological processes. These processes would not be executable without the system's precise control, which provides a suitable precondition for ensuring the high quality of manufactured products. However, the customer's demanding requirements are not always met. These involve increased requests for the quality of the final product due to the reduction of the tolerance band and application of high-strength materials. This paper aims to describe one of the solutions by which it is possible to achieve a higher quality of the machined surface after wire electrical discharge machining (WEDM). The solution proposes that through dynamic manage- ment, the WEDM process eliminates the vibrations of the wire tool electrode and thereby achieves a substantial increase in the quality of the eroded area in terms of its geometric accuracy. With the support of an extensive database of information with precise exchange of information, the proposed system will allow to control the elec- tro discharge process with regard to the optimal way of operation of the electro discharge machine on the basis of individually selected conditions. Key words: acoustic emission, dynamic control, Main Technological Parameters (MTP), Wire Electrical Discharge Machining (WEDM), Wire Tool Electrode (WTE) INTRODUCTION is characterized by a high quality of the machined surface, Modern engineering production, which uses special even the smallest deviation from the required dimension methods and technical equipment for machining high- or shape has a significant impact on the final quality of the strength materials, is characterized by high-quality prod- finished product 5, 23. One of the causes of this poor ucts. The attention is focused on such machining pro- quality is the vibration of the wire tool electrode. Alt- cesses, in which the mechanical properties of a commod- hough many experimental studies have been carried out ity and a tool have no limits 2. This mainly concerns the in this particular field, the most satisfying results have not machining manners where the material's degree of ma- been delivered yet. The experiments showed that the chinability is determined solely by its physical properties, wire tool electrode (WTE) vibrations vastly affect the geo- such as thermal and electrical conductivity, melting point metrical deviation of the eroded area 9, 11. Numerous 22, atomic valence, etc. Despite the use of these highly experiments also demonstrated that one of the main rea- sophisticated technologies, the customer's requirements sons for the WTE vibrations is the application of an im- for quality are not always met in terms of dimensional and proper WTE tensioning force. Furthermore, they found out that the magnitude of the WTE tensioning force geometric accuracy 3. These shortcomings are due to should be close to the critical values. This leads to a sub- the unsatisfactory design accuracy of the machine tool, an inadequate setting of the main and the managing techno- stantial reduction in the oscillation amplitude of the wire logical parameters, or the poor software control of the tool electrode during WEDM, resulting in a serious im- provement of the quality of the eroded surface in terms cutting process 4. Electrical discharge machining devices of geometric accuracy. In this regard, it is important to are especially prone to these types of faults. Since WEDM Ľ. STRAKA, P. KUCHTA – Dynamic Control of Discharge Energy During WEDM… 261 state that the WTE tensioning force can only be increased of electrical impulses in electro-erosive processes, the cri- up to a certain point. If the strength of the wire material terion for the minimization of WTE vibrations is absent. Therefore, our research aimed to design an algorithm for is exceeded, it will rupture 17. That could, in turn, lead the control of dynamic discharge energy during WEDM to an extension of the total machining time and thus to an that would minimize WTE vibrations. In terms of geomet- unpleasant effect on the overall WEDM productivity. Mul- tiple input factors influence the geometrical accuracy of ric accuracy, this should significantly contribute to in- creasing the final quality of the products, which are man- the eroded area 6, 10. In many cases, we cannot exactly ufactured using progressive WEDM technology. identify the principal originators of these geometrical er- rors. Mostly there are only conjectures and speculations. MATERIAL AND WORKING METHODS However, one thing is known for certain. All of these input Selection of a suitable measurement method for WTE vi- factors have a mutual denominator, and that is the preci- brations identification during WEDM sion of the WTE management, which is mainly affected by The inaccuracy of the WTE wiring due to its deflection hardware accuracy and software precision of wire move- from the straight position is caused by forces that arise as ment control 18-20. No less important is the setting of a result of the cyclic action of electric discharges during the main technological parameters (MTP), which are both the electro-erosive discharge process. In general, it can be primarily and secondarily involved in WTE vibrations, assumed that the greater the thickness of the machined which subsequently causes geometric inaccuracy of the material, the greater the deflection of the WTE. During eroded surface. Therefore, the experimental research the electro-erosive process, the thin WTE standardly os- aimed to identify the principal cause of these WTE vibra- cillates in the direction of the X and Y axes. The magnitude tions in order to design a fitting solution for their elimina- of its vibrations is directly dependent on the intensity of tion. generated electrical pulses. Fig. 1 shows the oscillation di- erosive process. rection of WTE during the electro-erosive process. LITERATURE REVIEW It is essential to focus on the originator of WTE vib rations if we want to find proper solutions to eliminate them. Based on a literary resources analysis, discharge energy was considered to be the primary causer. The energy is produced by an electric impulse generator. Nowadays, electro-erosive machining uses various types of these electric impulse generators. Most of them control the per- formance parameters to maximize cutting power. This new type of electric impulse generator that is applicable in the conditions of the electro-erosive process is de- scribed by the authors Qudeiri, J.E.A. et al. 15. However, the main deficiency of this electric impulse generator is the absence of an algorithm that would take into account the minimization of WTE vibrations. A different point of view on this issue was presented by researchers Yan, M.T. et al. 27. Their research concentrated on the develop- ment of a new type of impulse generator. This impulse generator differs from the standard types mainly in its a) roughing (fullcut) b) finishing (overcut) control algorithm, which not only maximizes EDM power Fig. 1 The direction of oscillation of the wire tool electrode dur- ing WEDM but also includes an algorithm that minimizes the rough- Source: 21. ness of the eroded surface. A similar type of electric im- pulse generator is also described by the authors Świercz, The oscillation character of the WTE differs depending on D.O. et al. 24. Nevertheless, in both cases, there is no whether a full cut or an offset cut is performed. If a rough- criterion in the control algorithm of the impulse generator ing operation is performed by a full cut, the WTE oscilla- for minimizing errors in the geometric accuracy of the tion will be executed as is shown in Fig. 1a. Fig. 1b shows eroded surface by eliminating WTE vibrations. A special the oscillation during the finishing process, when the WTE type of generator was also in a developing process carried performs an overcut. Partial compensation for these ad- out by Barik, S.K. et al. 1. Their electric impulse genera- verse effects can be achieved by applying special tor allows a power adjustment according to special quality measures. This is, in particular, a measure that includes requirements of the eroded area, but again lacks the pos- the counter-force in combination with a system that en- sibility of eliminating WTE vibrations. Another significant sures optimal WTE tension. Usually, tension force Fw for disadvantage of this generator is that it allows its applica- -2 the WTE with material strength up to 2000 N·mm ranges tion only in laboratory conditions. Based on the con- between 5 to 25 N. Its intensity is also primarily chosen ducted analysis in the field of development of electric im- concerning the diameter and material properties of the pulse generators, we concluded that in the control algo- WTE. Further reduction of WTE vibrations in this regard rithms of the ordinarily used systems for the generation 262 Management Systems in Production Engineering 2021, Volume 29, Issue 4 cannot be expected since, during WEDM, this force is gen- A portable digital laser measuring device PDV 100 Porta- erally chosen in the span of its limit values. However, ble Digital Vibrometer, used in the experimental measure- there is a potential for the elimination of WTE vibrations ment of WTE vibrations, can measure vibration velocities by modifying the concept of electric discharges. Neverthe- in the range from 0.5 Hz to 22 kHz. Thanks to its analog less, we must emphasize that this is a significant interven- and digital outputs, it provides digital processing of the tion in the traditional management system of generated measured signal, which can be transferred to a PC for sub- electrical impulses during the electro-erosive process. It is sequent analysis. necessary to look for such ways to eliminate WTE vibra- tions so that they do not negatively affect the perfor- Analysis of recorded WTE vibration values during WEDM mance of the electro-erosive process. On the contrary, it Based on the results of several experimental pieces of re- would be advantageous if by shortening the total machin- search in the field, it has been shown that the WTE vibra- ing time it could increase the economic efficiency 14. tions in the direction of the X-axis acquire slightly higher These goals can only be achieved with the collaboration values than the vibrations in the direction of the Y-axis. In terms of consequences, it can be clearly stated that the of highly sophisticated online monitoring and dynamic WTE vibrations in the X-axis direction have a significantly control systems. Currently, the information used to con- trol the electro-erosive process is derived from the actual smaller effect on the occurrence of the geometric inaccu- value parameters of electric discharge. The magnitude of racy of a machined surface because they are generated in the WTE tension, discharge current I, voltage U, working its feed direction. The problem, however, is the vibrations that are generated transversely to the WTE feed direction, gap, and others are monitored from these parameters 7, that is in the direction of the Y-axis. The magnitude of the 25. Yet, the current setting of the values of these param- critical oscillation frequency not only depends on the elec- eters does not take into account all the phenomena that tric discharge parameters, but also on other parameters occur at the place of electric discharge 13, 26. Therefore, such as the thickness of the machined material, the diam- it is crucial to include the phenomena related to WTE vi- eter of the wire electrode, its tensile force, and many oth- brations in the control algorithm as well. ers. Therefore, this critical frequency cannot be implicitly determined. The only possibility for its identification is the Identification of WTE vibrations during WEDM application of one of the measuring methods. Fig. 3 shows There are two basic approaches to identifying vibrations the maximum WTE oscillation amplitude depending on its in practice – direct and indirect. Although the direct meas- frequency, which occurs due to electric discharges gener- urement of the magnitude of the WTE vibrations is slightly ated during WEDM. more precise compared to the indirect one, in real-life conditions of an electro discharge machine, this method results in a large number of problems. The main issue con- cerns the location of sensors. The accuracy of the indirect method of measuring the magnitude of the WTE vibration is, in turn, affected by interferences, which to some extent distort the results of the measurements. When applying individual measuring methods, the right choice of the measuring technique is crucial. Consequently, for the ini- tial identification of the WTE vibrations in the experi- a) roughing cut mental research, a direct measuring method was applied using a laser measuring device PDV 100 Portable Digital Vibrometer. The course of measurement of the WTE vi- bration during WEDM is shown in Fig. 2. b) finishing cut (overcut) Fig. 3 Dependence of the oscillation amplitude of the wire tool electrode on the oscillation frequency of the WTE generated by the influence of electric discharges during WEDM Based on the performed experimental measurements, it was also shown that the magnitude of the oscillation am- plitude of the WTE is not directly proportional to its oscil- lation frequency. As can be observed from the graph in Fig. 3, its maximum value was reached by applying the Fig. 2 Application of the direct measuring method of WTE critical frequency of the WTE oscillation, generated by the vibrations during WEDM influence of electric discharges during WEDM. At the Ľ. STRAKA, P. KUCHTA – Dynamic Control of Discharge Energy During WEDM… 263 same time, its value varies not only depending on the the application of optimization techniques based on pro- thickness of the machined material or the properties of cess algorithms. The use of such algorithms, which guar- the WTE, but also on the machining method itself. antee high convergence in the process of optimum iden- tification, is particularly suitable [28]. To ensure the ideal Design of an algorithm for dynamic control of discharge functionality of the control system of the generated elec- energy during WEDM trical pulses, a mechanism enabling the required choice of Even though there is now an increasing emphasis on the the optimization criterion must also be implemented in complexity of knowing the set of individual characteristics the system. of electric discharges during WEDM, comprehensive iden- This means that in real action, the possibility of choosing tification of their interrelationships is still lacking. Also, an optimization criterion would be primarily focused on there are no proposals to minimize the adverse effect of achieving high quality of the machined surface, high electric discharges on the quality of the machined surface productivity of the electro-erosive process, high efficiency after WEDM in terms of the achieved geometric accuracy. of the electro-erosive process, or a combination thereof. A certain solution to this problem is to design a dynamic This requires an expert system based on an extensive in- control of the discharge energy of electrical impulses dur- formation database. Its proper connection with the con- ing WEDM. Its goal is to eliminate WTE vibrations, which trol system of the electro-erosive machine would thus en- will improve the geometric accuracy of the eroded sur- able efficient operation not only in serial but also in piece face. However, this requires a precise design of the con- production. trol algorithm. The practical advantage of the proposed Design of a system for dynamic control of discharge en- algorithm would also be to include optimization mathe- ergy during WEDM in a real electro-erosive machine con- matical models that, based on input parameters related ditions to material and dimensional properties of the workpiece Regarding the use of machining processes with a non-sta- and wire tool electrode, allow automatic adjustment of tionary character, which also includes electro-erosive ma- MTP for the required quality of the eroded surface in chining; highly reliable control systems are required to terms of its parameters of roughness. control the discharge energy. These systems are supposed Most importantly, a correct design of the measuring chain to effectively determine the optimal parameters of the is necessary when designing an algorithm for dynamic electro-erosive process with respect to the demanded control of discharge energy during WEDM in order to quality of the machined surface. The design of such a eliminate WTE vibrations. It is inevitable to define the sen- management system should implement the principles of sors that will transmit the recorded signal to the control self-organization using advanced methods and highly so- system of the electric pulse generator and the control sys- phisticated technical means. The following Fig. 5 demon- tem of the electro-erosive machine. Using the transmitted strates a schematic diagram of the connection of the AE input information, they will adjust the parameters of the sensors with the dynamic control system of the EDM ma- electric discharge so as to reduce the oscillation frequency chine, which will enable the elimination of undesired WTE of the WTE. The following Fig. 4 shows a design of a con- vibrations during WEDM. trol algorithm for dynamic control of discharge energy during WEDM, the task of which is to minimize the vibra- tions of the WTE in order to achieve a higher quality of the eroded surface in terms of its geometric accuracy. Fig. 5 Diagram of dynamic control of generated discharge en- ergy during WEDM A major problem with the direct method of measuring WTE vibrations during WEDM is the setting up of sensors. These would always have to be re-established for each specific Fig. 4 Algorithm for dynamic discharge energy control during condition of the machining process, which is unacceptable WEDM from a practical point of view. Therefore, despite the above-mentioned negative aspects of the indirect method A characteristic feature of the proposed system for dy- of measuring WTE vibrations during the electro-erosive namic control of discharge energy during WEDM is also process, acoustic emission (AE) sensors based on this 264 Management Systems in Production Engineering 2021, Volume 29, Issue 4 method have been implemented in the proposed system. certain combination of several factors creates the maxi- An overlap of electromagnetic interference (EMI) with the mum oscillation amplitude of WTE. Yet, this frequency is scanned AE signals might be a risk in this method of indirect constantly changing according to special conditions. There- WTE vibration measurement. However, it is possible to fil- fore, it was necessary to focus on a solution that can dy- ter this interfering element by a suitable intervention. namically respond to the change. One of the acceptable Providing there is a large thickness of the machined mate- ways to identify ever-changing WTE vibrations has been the rial or some specific values of the setting of the parameters indirect method of AE sensing. As the problem-solving re- of the electric discharge, there might be a slight increase in sult was considered to be the inclusion of the WTE vibra- the amplitude of the oscillation of the WTE at one of its tions parameter in the control algorithm as another param- ends. Accordingly, it seemed advantageous to place the AE eter within the monitored parameters of the electro dis- sensors on both the top and bottom of the WTE line. The charge process. This input parameter in the process of con- recorded values could be distorted if the AE sensor is placed trolling the generated electric discharges has made it pos- on only one of the lines. The signals received from the AE sible to acquire a new dimension in the field of increasing sensors will be transmitted to the A/D converter. Subse- the final quality of products produced by progressive elec- quently, the filtered and modified information will be im- tro-erosive technology. Additionally, by monitoring a given ported into the control system of the electro-erosive ma- process parameter, it is possible to achieve a substantial in- chine. Based on this input data, the machine will adjust the crease in the level of intelligent dynamic control of the elec- electric discharge parameters to increase or decrease the tro-erosive process. It can also detect and subsequently, by frequency, thereby minimizing the side effect of the maxi- a suitable modification of the generated electrical pulses mum oscillation amplitude of the WTE. eliminate the occurrence of undesired electrical discharges, which increase the amplitude of the oscillation of the wire DISCUSSION electrode. This information is valuable because it allows the Commonly used electro-erosive devices allow the genera- application of an advanced electric discharge control strat- tion of electric discharges only on the basis of current con- egy, thus eliminating the adverse impact of improper MTP ditions in the working gap. Their control system adjusts the selection. Overall, the result is not only an increase in the power characteristics of the pulse generator based on the final quality of products and ensuring the stability of the dis- measurement of the values of electric voltage and current charge process, but ultimately also an increase in the total in the working gap according to predetermined reference WEDM productivity. values acquired from the compiled control algorithms. However, in order to meet the demanding requirements ACKNOWLEDGMENTS for the quality of the machined surface in terms of its geo- The authors would like to thank the grant agency for sup- metric accuracy, monitoring of only the mentioned param- porting research work the project VEGA 1/0205/19. eters is insufficient [8]. Nevertheless, these demanding re- quirements for product quality can be met by integrating REFERENCES [1] S.K. Barik and P.S. Rao. “Design of Pulse Circuit of EDM Die- the most modern technologies for monitoring and dynamic sinker.” International Research Journal of Engineering and control of the electro-erosive process [12, 16]. This will sig- Technology, vol. 3(5), pp. 2762-2765, 2016. nificantly increase not only its stability and cutting perfor- [2] F. Botko, M. Hatala, P. Beraxa, J. Duplák and J. Zajac. “De- mance but also the final quality of products produced by termination of CVD coating thickness for shaped surface progressive WEDM technology. Concurrently, it can be tool.” TEM Journal, vol. 7(2), pp. 428-432, 2018. stated that the application of a dynamic control system of [3] R. Davis, A. Singh, S. Kachhap and N. Nath. “A comparative generated electrical impulses during WEDM based on input study of EDD and PM-EDD in producing holes in inconel information from the field of electric discharge is an effec- 718 alloy.” Key Engineering Materials, vol. 833, pp. 48-53, tive means of eliminating WTE vibrations. A characteristic 2020. [4] E. Evin, M. Tomáš and J. Kmec. “Optimization of electro- feature of the proposed dynamic system for controlling the discharge texturing parameters for steel sheets' finishing generated discharge energy during WEDM is also its flexi- rollers.” Materials, vol. 13(5), art. no. 1223, 2020. bility and openness to real-life conditions. Based on an ex- [5] S. Hamed, L.A. Al-Juboori, V.N. Najm and A.M. Saleh. “Ana- tensive database of information, as well as the fast and ac- lysis the impact of WEDM parameters on surface curate exchange of information with the external environ- microstructure using response surface methodology.” A- ment, the system will allow a controlling of the electro-ero- SET 2020, Advances in Science and Engineering Technology sive process with respect to the optimal way of operation International Conferences, Dubai, 4-9 February 2020, art of the electro-erosive machine according to the individually no. 9118208, 2020. selected optimization criteria. [6] S. Hašová and Ľ. Straka. “Design and verification of soft- ware for simulation of selected quality indicators of machi- ned surface after WEDM.” Academic Journal of Manufac- CONCLUSION turing Engineering, vol. 14(2), pp. 13-20, 2016. The results of several studies demonstrate that the geo- [7] E. Kuznetsov, V. Nahornyi and T. Krenicky. “Gas Flow Simu- metric deviations of the eroded surface are mainly caused lation in the Working Gap of Impulse Gas-barrier Face by WTE vibrations. Therefore, it was crucial to find an ac- Seal.” Management Systems in Production Engineering, ceptable solution to eliminate them. Based on the out- vol. 28(4), pp. 298-303, 2020. comes of experimental research, it has been shown that a Ľ. STRAKA, P. KUCHTA – Dynamic Control of Discharge Energy During WEDM… 265 [8] J. Maščenik. “Implementation of the designed program for [18] Ľ. Straka and G. Dittrich. “Influence of tool steel properties calculation and check of chain gears.” MM Science Journal, on surface quality after electrical discharge machining by vol. 2019 (december), pp. 3431-3434, 2019. wire electrode.” The International Journal of Advanced [9] K. Mouralova, L. Benes, J. Bednar, R. Zahradnicek, T. Pro- Manufacturing Technology, vol. 106(5-6), pp. 1617-1632, kes and J. Fries. “Analysis of machinability and crack occur- 2020. rence of steels 1.2363 and 1.2343ESR machined by die-sin- [19] Ľ. Straka, I. Čorný, J. Piteľ and S. Hašová. “Statistical Ap- king EDM.” Coatings, vol. 10(4), art. no. 406, 2020. proach to Optimize the Process Parameters of HAZ of Tool [10] V. Ngocpi, D.T. Tam, N.M. Cuong and T.H. Tran. “Multi-ob- Steel EN X32CrMoV12-28 after Die-Sinking EDM with SF- jective optimization of PMEDM process parameters for Cu Electrode.” Metals, vol. 7(2), pp. 1-22, 2017. processing cylindrical shaped parts using taguchi method [20] Ľ. Straka and S. Hašová. “The critical failure determination and grey relational analysis.” International Journal of Me- of the constructional parts of autonomous electroerosion chanical and Production Engineering Research and Develo- equipment by applying Boolean logic. ”Academic Journal pment, vol. 10(2), pp. 669-678, 2020. of Manufacturing Engineering, vol. 14(2), pp. 80-86, 2016. [11] Š. Olejarova and T. Krenicky. “Monitoring the condition of [21] Ľ. Straka and G. Dittrich. “Intelligent control system of ge- the spindle of the milling machine using vibration.” MM nerated electrical pulses at discharge machining.” Science Journal, vol. 2016(11), pp. 1227-1231, 2016. Emerging trends in mechatronics, IntechOpen, 26 p., 2020. [12] A. Panda, Š. Olejárová, J. Valíček and M. Harničárová.” Mo- [22] L. Sukhodub, A. Panda, K. Dyadyura, I. Pandová and T. Kre- nitoring of the condition of turning machine bearing hou- nický. “The design criteria for biodegradable magnesium sing through vibrations.” The International Journal of Ad- alloy implants.” MM Science Journal, vol. 2018(Decem- vanced Manufacturing Technology, vol. 97(1-4), pp. 401- ber), pp. 2673-2679, 2018. 411, 2018. [23] D. Oniszczuk-Swiercz, R. Swiercz, T. Chmielewski and T. Sa- [13] A. Panda, V. Nahornyi, I. Pandová, M. Harničárová, M. lacinski. “Experimental investigation of influence WEDM Kušnerová, J. Valíček and J. Kmec. “Development of the parameters on surface roughness and flatness deviation.” method for predicting the resource of mechanical sys- Metal 2020, vol. 29, p. 611-617, 2020. tems.” The International Journal of Advanced Manufac- [24] D.O. Świercz and R. Świercz. “EDM – analyses of current turing Technology, vol. 105(1-4), pp. 1563-1571, 2019. and voltage waveforms.” Mechanik, vol. 2, pp. 1-3, 2017. [14] M. Pollák and J. Tkáč. “Enterprise information data ma- [25] R. Swiercz, and R. Holubek. “Experimental investigation of nagement system for small manufacturing company.” TEM influence electrical discharge energy on the surface layer Journal – Technology, Education, Management, Informa- properties after EDM.” Welding Technology Review, vol. tics, vol. 8(4), pp. 1169-1175, 2019. 92(5), pp. 7-13, 2020. [15] J.E.A. Qudeiri, A. Saleh, A. Ziout, A.H.I. Mourad, M.H. Abidi [26] J. Wang, J.A. Sánchez, B. Izquierdo and I. Ayesta. “Experi- and A. Elkaseer. “Advanced Electric Discharge Machining mental and numerical study of crater volume in wire of Stainless Steels: Assessment of the State of the Art, electrical discharge machining.” Materials, vol. 13(3), art. Gaps and Future Prospect.” Materials, vol. 2019(12), a.no. no. 577, 2020. 907, 2019. [27] M.T. Yan and T.Ch. Lin. “Development of a Pulse Generator [16] M. Rimár, M. Fedák, A. Kulikov and P. Šmeringai. “Study of for Rough Cutting of Oil-based Micro Wire-EDM.” ISEM gaseous flows in closed area with forced ventilation.” MM XVIII, Procedia CIRP, vol. 42, pp. 709-714, 2016. Science Journal, vol. 2018(3), pp. 2188-2191, 2018. [28] D. Zhou, Ch. Sun, Y. Zhang and P. Wang. “A noncontact full- [17] P. Shandilya, P.K. Jain and N.K. Jain. “Modelling and pro- field flatness measuring system based on fringe projec- cess optimisation for wire electric discharge machining of tion.” Proceedings of SPIE, vol. 11439, art.no. 114391B, metal matrix composites.” International Journal of Machi- 2020. ning and Machinability of Materials, vol. 18, pp. 119-1207, Ľuboslav Straka ORCID ID: 0000-0003-0914-2155 Technical University of Kosice with a seat in Prešov Faculty of Manufacturing Technologies Department of Automotive and Manufacturing Technologies Štúrova 31, Prešov, Slovakia e-mail: luboslav.straka@tuke.sk, Patrik Kuchta Technical University of Kosice with a seat in Prešov Faculty of Manufacturing Technologies Department of Automotive and Manufacturing Technologies Štúrova 31, Prešov, Slovakia e-mail: patrik.kuchta@tuke.sk

Journal

Management Systems in Production Engineeringde Gruyter

Published: Dec 1, 2021

Keywords: acoustic emission; dynamic control; Main Technological Parameters (MTP); Wire Electrical Discharge Machining (WEDM); Wire Tool Electrode (WTE)

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