Electrical Discharge Machining Non-Conductive Ceramics: Combination of Materials

Round 1

Reviewer 1 Report

This review is mainly aimed to update the existing knowledge about electrical discharge machining of the most hard-to-machine materials as non-conductive ceramics. This study is suitable to be submitted to Technologies but some problems should be carefully revised before being considered for publication.

1. It is not suitable to use acronym in the title.
2. This article focuses on the research on a suitable combination of the materials for processing oxide ceramics as aluminum oxide and zirconium dioxide. However, the Introduction section is less related to this topic. I suggest the authors revise the introduction section to explicit the substance of the manuscript.
3. Line 396-398, Page 15. These sentences seem to lack in support, the authors should explain it in detail.
4. Some typos and grammatical errors should be carefully revised. Page 16, C2O3 for example.

 

Author Response

Dear reviewer,

Thank you very much for your kind reply and the evaluation of our research. We found the comments very useful and detailed. We believe that it can improve the quality of this manuscript.

We would like to introduce our response to your comments:

Point 1. It is not suitable to use acronym in the title.

Response 1. The title was modified according to the reviewer’s comment.

Point 2. This article focuses on the research on a suitable combination of the materials for processing oxide ceramics as aluminum oxide and zirconium dioxide. However, the Introduction section is less related to this topic. I suggest the authors revise the introduction section to explicit the substance of the manuscript.

Response 2. Thank you very much for your attention to the details. The introduction of the manuscript was revised according to your comments.

Point 3. Line 396-398, Page 15. These sentences seem to lack in support, the authors should explain it in detail.

Response 3. The reviewer was right as these sentences had an awkward structure and did not was supported by relevant references.  The authors tried to modify it to make clear the main idea:

Zirconia ZrO₂ tends to change its electrical properties in the presence of heat up to 2000°C (Figure 3), but it is inert to the water medium.

The zirconium starts actively to absorb hydrogen H₂ at temperatures around 250-300°C forming solid solution and hydrides ZrH_x (x=0.05-2) representing fragile sulfur black powder. The hydride powder is stable at room temperature but ignites at 430°C on the air when the hydride crystals are stable up to 600–750°C and then they decompose with the release of hydrogen and dissociate to the pure metal at 1200–1300ºC in a vacuum [132,133]. Thus, the released hydrides may not cause any difficulties during electrical discharge machining.

Point 4. Some typos and grammatical errors should be carefully revised. Page 16, C2O3 for example.

Response 4. Thank you very much that you noticed it. Due to the large volume of the discussed material, we tried to give for each chemical composition formula and texted name to avoid any misunderstanding. In this case, it was misprinting. We tried to follow your advice and have checked it through the text of the manuscript.

Author Response File: Author Response.docx

Reviewer 2 Report

The proposed manuscript deals with the combination of materials for electrical discharge machining of non-conductive ceramics such as Al₂O₃ and ZrO₂.

In this review author present a comprehensive theoretical background to the principles of electrical discharge machining of ceramics, properties and sintering of ceramic materials.

 

I have recognised that interesting results have been put forward in Authors paper. The characterization and analysis of the existing nonconductive ceramics and materials for auxiliary electrodes, electrode tools, conductive additives and powders was carried out correctly. The authors show here a high orientation in relevant literature but also in practical questions of used technologies.

 

There are however some recommendations for minor revision.

 

• Page 4, raw. 117. The reference of Lazarenko at al. work is suitable to add instead of prof. Boris Lazarenko and prof. Natalyia Lazarenko.

 

• Page 6, raw 208. Not only addition of secondary phase in the form of powders and tubes to ceramic matrix can improve the mechanical properties, but also phases in the form of nano or micro platelets and fibers are helpful to increase strength and fracture toughness.

 

• Page 7, raw 225. The statement that cold-pressed ceramics are slightly higher than hot –pressed ceramics is very disputable.  I suggest addition more references to confirm it.

Author Response

Dear reviewer,

Thank you very much for your time and high evaluation of our researching work. We found the comments very useful and detailed. We believe that it can improve the quality of this manuscript. We would like to introduce our response to your kind comments below.

Kind regards,

Authors

Response

Point 1. Page 4, raw. 117. The reference of Lazarenko at al. work is suitable to add instead of prof. Boris Lazarenko and prof. Natalyia Lazarenko.

Response 1. We do agree with the valuable suggestion of the reviewer. The relevant reference was included in the text.

Point 2. Page 6, raw 208. Not only addition of secondary phase in the form of powders and tubes to ceramic matrix can improve the mechanical properties, but also phases in the form of nano or micro platelets and fibers are helpful to increase strength and fracture toughness.

Response 2. We do agree with the proposed correction. The relevant changes were introduced in the text on page 6, line 221-223.

Point 3. Page 7, raw 225. The statement that cold-pressed ceramics are slightly higher than hot –pressed ceramics is very disputable.  I suggest addition more references to confirm it.

Response 3. We do agree with the proposed critique. It was decided to reveal the topic related to different pressing and compaction methods for ceramics since there are not so many classifications published in open access journals.  The relevant changes were introduced in the text on page 7, line 253-287. The added references are provided below. We hope that the reviewer finds them appropriate and adequate for the introduced changes.

References

1. Orlova, A.I.; Ojovan, M.I. Ceramic Mineral Waste-Forms for Nuclear Waste Immobilization. Materials2019, 12, 2638.
2. Kachaev, A.A.; Grashchenkov, D.V.; Lebedeva, Y.E.; Solntsev, S.S.; Khasanov, O.L. Optically Transparent Ceramic (Review). Glass Ceram 2016, 73(3-4), 117-123.
3. Lyamina, G.V.; Ilela, A.E., Dvilis, E.S.; Petyukevich, M.A.; Tolkachev, O.S. Medical Ceramics from Powders of the System Al2O3–ZrO2–Y2O3 Obtained on an Installation of Nanospray Drying. Nanotechnol Russ 2018, 13(5-6), 337-343.
4. Gommeringer, A.; Kern, F. Mechanical Properties and Electrical Discharge Machinability of Alumina-10 vol% Zirconia-28 vol% Titanium Nitride Composites. Ceramics2020, 3, 199-209.
5. Boulesteix, R.; Chevarin, C.; Belon, R.; Maître, A.; Cochain, L.; Sallé, C. Manufacturing of Large Size and Highly Transparent Nd:YAG Ceramics by Pressure Slip-Casting and Post-Sintering by HIP: An Experimental and Simulation Study. Materials2020, 13, 2199.
6. Maksimov, R.N.; Khrustov, V.R.; Shitov, V.A.; Yurovskikh, A.S. Effect of the Thermal Shrinkage Behavior of Yb:Lu2O3 Nanopowder Compacts on the Structural and Optical Characteristics of Ceramics. Inorg Mater 2019, 55(6), 634-639.
7. Grishaev, V.V.; Tostanovskii, V.I. Properties of oxide structural ceramics made from mechanically milled powders. Refract 1993, 34(1-2), 98-102.
8. Annenkov, Y.M.; Ivanov, V.V.; Ivashutenko, A.S.I.; Kondratyuk, A.A.; Sivkov, A.A. Efficiency of different compaction methods for corundum-zirconia powders. Refract Ind Ceram 2008, 49(6), 461-465.
9. Gavrilkin, S.M.; Kopaneva, L.I.; Batsanov, S.S. Anomalous Phase Transition in Shock-Compressed PbO. Combustion, Explosion and Shock Waves 2003, 39(6), 723-726.
10. Grigoriev, S.N.; Dmitriev, A.M.; Korobova, N.V.; Fedorov, S.V. A Cold-Pressing Method Combining Axial and Shear Flow of Powder Compaction to Produce High-Density Iron Parts. Technologies 2019, 7, 70.
11. Lazar, A.; Kosmač, T.; Zavašnik, J.; Abram, A.; Kocjan, A. TiN-nanoparticulate-reinforced ZrO2 for electrical discharge machining. Materials 2019, 12(7), 2789.
12. Morozova, L.V.; Kalinina, M.V.; Drozdova, I.A.; Shilova, O.A. Preparation and Characterization of Nanoceramics for Solid Oxide Fuel Cells. Inorg Mater 2018 , 54(1), 79-86.
13. Khasanov, O.L.; Pokholkov, Yu.P.; Sokolov, V.M.; Dvilis, É.S.; Slosman, A.I.; Matrenin, S.V. Ultrasonic compacting of zirconium ceramics from ultradispersed powders. Glass Ceram 1995, 52(7), 177-180.
14. Gadow, R.; Kern, F. Pressureless sintering of injection molded zirconia toughened alumina nanocomposites. J Ceram Soc Jpn 2006, 114(1335), 958-962.

Author Response File: Author Response.docx

Reviewer 3 Report

"On Combination of Materials for EDM of Non-Conductive Ceramics"

 

The Authors present and discuss on the research of a suitable combination of materials for processing (by electrical discharge machining - EDM) of oxide ceramics such as aluminium oxide and zirconium oxide, as non-conductive ceramics. The manuscript is very descriptive and needs further and thorough revision; it should not be accepted for publication in this present form.

The Authors need to also take into account the "General Considerations" of the "Manuscript Preparation", available at https://www.mdpi.com/journal/Technologies/instructions. 

• Title: remove the acronym and rephrase it; consider something simple and clear such as "Electrical discharge machining of non-conductive ceramics as composites";
• Abstract: not meaningful, please rephrase it to provide more on the actual and significant values / data; do not use acronyms prior to correctly presenting the full name of the device, technique, etc (e.g. electrical discharge machining - EDM);
• Graphical abstract: not provided;
• Highlights: not provided;
• Keywords: meaningful.

 

1. Introduction

• this section is comprehensive yet the Authors use long phrases, unnecessary examples, and in some cases it's rather difficult to follow; please rephrase it.
• the Authors must further insist on the importance and novelty of their work with respect to literature; further explain on your choice on this approach.
• further explain on your choice on this approach.
  
  

2. Experimental approach / Materials and methods

• this section needs to include sections "2. Problem statement", "3. Properties of Ceramics", "4. Sintering of Ceramics", and any discussion with respect to the experimental approach and/or the materials and methods;
• therefore, the Authors need to thoroughly rephrase and merge these sections.
  
  
  

3. Results and discussion

• this section should include "5. Combination of the Materials for EDM of Non-Conductive Ceramics", and any related discussion to understanding the data; please thoroughly rephrase;
• the Authors need to further discuss the results in a more correlated manner;
  
  
  

4. Conclusion

• this section is meaningful, but please rephrase it to insist more on the novelty and importance of your work; provide more on the actual and significant values / data.
  
  
  
  Minor aspects
  
  The Authors need to avoid providing redundant data, superfluous text, or the repetitive use of speculative words or phrases; check the manuscript for typographical errors (language, spelling, punctuation, numbering of sections, etc).
  
  
  
  To conclude, the manuscript should not be accepted for publication in its present form. Further revision is needed.

Author Response

Dear reviewer,

Thank you very much for your time and high evaluation of our researching work. We found the comments very useful and detailed. We believe that it can improve the quality of this manuscript. We would like to introduce our response to your kind comments below.

Kind regards,

Authors

Response

Point 1. The Authors need to also take into account the "General Considerations" of the "Manuscript Preparation", available at https://www.mdpi.com/journal/Technologies/instructions.

Response 1. We do agree with the valuable suggestion of the reviewer. We tried to follow the standards of the journal for review manuscripts. Top- and backstages were introduced from the template. The other sections are related to the literature review. The graphical abstract is provided. All the figures are drawn with the quality of representation of 600 dpi. Abbreviations are removed from the title, abstract, everywhere in the text where it is possible. All the data provided in the International System of Units. Equations are presented in the Microsoft Equation Editor. The authors provided no supplementary materials. The representation of the manuscript was checked once again according to the https://www.mdpi.com/editorial_process

Point 2. Title: remove the acronym and rephrase it; consider something simple and clear such as "Electrical discharge machining of non-conductive ceramics as composites";

Response 2. We do agree with the valuable suggestion of the reviewer. The acronym was removed from the title. The current title is “Electrical Discharge Machining Non-Conductive Ceramics: Combination of Materials”.

Point 3. Abstract: not meaningful, please rephrase it to provide more on the actual and significant values / data; do not use acronyms prior to correctly presenting the full name of the device, technique, etc (e.g. electrical discharge machining - EDM);

Response 3. We do agree with the valuable suggestion of the reviewer. The abstract was rewritten. We tried to do it actual and significant, provided more data on the review, deleted all acronyms. We hope that the reviewer will find this abstract more adequate to the high standards of the journal.

NOW: One of the promising processing methods for non-conductive structural and functional ceramics based on ZrO₂, Al₂O₃, and Si₃N₄ systems is electrical discharge machining with the assistance of an auxiliary electrode that can be presented in the form of conductive films with a thickness of 4-10 µm or nanoparticles - granules, tubes, platelets, multidimensional particles added in the working zone as a free poured powder the concentration of which provided by ultrasound emission or by dielectric flows or as conductive additives in the structure of nanocomposites. However, the described experimental approaches did not reach the production market and industry. It is related mostly to the chaotic development of the knowledge and non-systematized data in the field when researchers often can not ground their choice of the material for auxiliary electrodes, assisting powders, or nano additives or they can not explain the nature of processes that were observed in the working tank during experiments when their results are not correlated to the measured specific electrical conductivity of the electrodes, particles, ceramic workpieces or nanocomposites but depends on something else. The proposed review includes data on the main electrophysical and chemical properties of the components in the presence of heat when the temperature in the interelectrode gap reaches 10,000°C, and the systematization of data on ceramic pressing methods, including spark plasma sintering, the chemical reactions that occur in the interelectrode gap during sublimation of primary (brass and copper) and auxiliary electrodes made of transition metals Ti, Cr, Co, and carbon, auxiliary electrodes made of metals with low melting point Zn, Ag, Au, Al, assisting powder of oxide ceramics TiO₂, CeO₂, SnO₂, ITO, conductive additives Cu, W, TiC, WC and components of Al₂O₃ and Zr₂O workpieces in interaction with the dielectric fluid - water and oil/kerosene medium.

BEFORE: Non-conductive ceramics become more widespread nowadays due to its excellent exploitation properties. However, there are a few opportunities to machine them. One of the actual methods for processing of non-conductive oxide ceramics is electrical discharge machining with the assistance of an auxiliary electrode that can be presented in the form of thin films of nanoparticles in the new nanocomposite. Both of the approaches did not reach the production market and manufacturing industry and stay on the stage of experimental approbation. The article is related to the research on a suitable combination of the materials for processing oxide ceramics as aluminum oxide and zirconium dioxide. The dialectical method of cognition was used as a scientific approach to solve the problem of the combination of the materials based on their electrical conductivity and chemical activity in the presence of the heat associated with the sublimation phenomena in the inter-electrode gap. The developed approach includes the systematization of the most common non-conductive ceramics and materials for auxiliary electrodes, electrode-tools, conductive nanoparticles in the role of conductive additives of ceramic nanocomposites, and assisting powder. The results of the study are aimed to update the existing knowledge about EDM of the most hard-to-machine materials as non-conductive ceramics are.

Point 4. Graphical abstract: not provided;

Response 4. Thank you for this useful suggestion. The graphical abstract was provided.

Point 5. Highlights: not provided;

Response 5. Thank you for this useful suggestion. The highlights were provided at the end of the manuscript.

Highlights

• The systematization of data on ceramic pressing and sintering methods
• The systematization of electrophysical and chemical properties of oxide ceramics in the presence of heat.
• The classification of chemical reactions during sublimation and cooling of droplets of components of primary (brass or copper) and auxiliary electrodes made of transition metals Ti, Cr, Co, and carbon with components of Al₂O₃ and Zr₂O workpieces, water or oil/kerosene medium in the interelectrode gap
• The classification of chemical reactions during sublimation of primary (brass or copper) and auxiliary electrodes made of metals with low melting point Zn, Ag, Au, Al with components of Al₂O₃ and Zr₂O workpieces, water or oil/kerosene medium in the interelectrode gap
• The classification of chemical reactions during sublimation of primary (brass or copper) and assisting powder of oxide ceramics TiO₂, CeO₂, SnO₂, ITO and components of Al₂O₃ and Zr₂O workpieces, water or oil/kerosene medium in the interelectrode gap
• The classification of chemical reactions during sublimation of primary (brass or copper) and conductive additives Cu, W, TiC, WC and components of Al₂O₃ and Zr₂O workpieces, water or oil/kerosene medium in the interelectrode gap

Point 6. Keywords: meaningful.

Response 6. Thank you for your kind evaluation. They were updated.

Point 7. Introduction

this section is comprehensive yet the Authors use long phrases, unnecessary examples, and in some cases it's rather difficult to follow; please rephrase it.

the Authors must further insist on the importance and novelty of their work with respect to literature; further explain on your choice on this approach.

further explain on your choice on this approach.

Response 7. We tried to revise the Introduction according to the reviewer's comments. We hope that the reviewer will find the revised introduction more suitable for publication. We have deleted an example to simplify the text. We would like to stay the rest if the reviewer will find it suitable for keeping the main idea of the study. We introduced two paragraphs at the end of the introduction – the novelty of the study and the purpose of this study. If the reviewer will find them not suitable, we are ready to rephrase or revise them.

Point 8. Experimental approach / Materials and methods

this section needs to include sections "2. Problem statement", "3. Properties of Ceramics", "4. Sintering of Ceramics", and any discussion with respect to the experimental approach and/or the materials and methods;

therefore, the Authors need to thoroughly rephrase and merge these sections.

Response 8. In the article, we tried to follow the recommendation of the Journal about the more flexible structure of the text, when we had no experiments that we would like to discuss in the text, but to do a completely analytical study. We are ready to provide the publish examples if it is required.

Point 9. Results and discussion

this section should include "5. Combination of the Materials for EDM of Non-Conductive Ceramics", and any related discussion to understanding the data; please thoroughly rephrase;

the Authors need to further discuss the results in a more correlated manner;

Response 9. All our results are a discussion on the proposed subject. There are only analytical data of the literature review that discussed in each section. The systematizations of literature data are presented in the form of tables and figures.

Point 10. Conclusion

this section is meaningful, but please rephrase it to insist more on the novelty and importance of your work; provide more on the actual and significant values / data.

Response 10. Thank you for your valuable comment. We have updated this section by summarizing the most valuable conclusions in our opinion and the novelty of the work.

Point 11. Minor aspects

The Authors need to avoid providing redundant data, superfluous text, or the repetitive use of speculative words or phrases; check the manuscript for typographical errors (language, spelling, punctuation, numbering of sections, etc).

Response 11. Thank you for pointing it. We tried to follow your suggestion.

Author Response File: Author Response.docx

Reviewer 4 Report

I think that the present review is well written and the topic is interesting but some parts are too scholastic for a review, e.g. section 3. Properties of ceramics and the next Sintering of ceramics, that is numbered as section 3 as well. 

I'm not fully convinced that all the contents of this work represent a significan contribution for the scientific community. 

Author Response

Dear reviewer,

Thank you very much for your evaluation of our researching work, our work with the large volume of sources with the purpose of highlighting the existed problem related to the lack of knowledge in the basic principles of physics and chemistry of materials. We found the comments very useful and detailed. We believe that it can improve the quality of this manuscript. We would like to introduce our response to your comments below.

With best regards,

Authors

Response

Point 1. I think that the present review is well written and the topic is interesting but some parts are too scholastic for a review, e.g. section 3. Properties of ceramics and the next Sintering of ceramics, that is numbered as section 3 as well.

Response 1. We do agree with the valuable opinion of the reviewer. Some fragments of the review indeed look too scholastic. We tried to rewrite some paragraphs to make them more analytical for the potential readers of the journal. We had modified a number of the section related to the description of the sintering technology of ceramics from 3 to 4 and numbers of other following sections.

Point 2. I'm not fully convinced that all the contents of this work represent a significan contribution for the scientific community.

Response 2. Some parts of the review may repeat well-known physics of materials, non-organic chemistry, and technology knowledge. Meanwhile, if we look carefully at the current tendencies in the researches of young and non-experienced authors, we will find plenty of doubtful examples on a combination of materials, especially in the cases of additives, assisting powders, or auxiliary electrodes that, e.g., related to an absence of minimal understanding of the fundamental processes that happened during electrical discharge machining with components. If the process of electrical discharge machining of conventional materials is well known, the new techniques of electrical discharge machining non-conductive materials stay unveiled and demand new studies that will help to open a new stage in the industry.

Among new studies, we can find plenty of works that based only on ANOVA with a combination of the materials that are not suitable for machining, can have not electro physical nature of destruction, undesired consequences, or be even dangerous [1,2]. However, the researchers did try what they propose on practice and promise outstanding success with their optimized parameters. It is one of the typical flaws. E.g., the authors propose to use aluminum powder during electrical discharge machining in oil or kerosene. They do not understand why the process provides a cloud of dirty stuff in the work tank [3-5]. Other authors tried to use cerium dioxide powder with a brass tool or suggest to machine nickel alloy with a brass tool when a combination of Ce and Zn or Ni and Zn gives at least sparks and dirty dust in the work tank, and the quality of the obtained surfaces quite low due to not electro physical but chemical nature of destruction [6-9]. Sometimes we can also find in the papers that they had a melting process (“through melting and vaporization”) instead of sublimation [10-12]. There is definitely no melting at 10,000K.

One of our high-reputation colleagues have sintered for plenty of years for his research pure ceramics Al₂O₃ and ZrO₂ but in black color. Then someone has noticed it, that they should be more white than black or grey, they had found out that their high-pressure sealings were worn out and they do not why. Probably, that can find it in our modest review that we what to publish in this open-access journal their first mistake was the use of carbon dies during sintering of alumina.

Once we met a work where the authors under the supervision of a very famous and known professor of the top-50 world technical universities found out experimentally some blue powders in the working zone. In the conclusions of this manuscript, they did not specify it when it was a toxic form of copper. Luckily, one of our authors had reviewed this manuscript, and the text of the manuscript was updated by a phrase that this experiment should be repeated only in the proper conditions to avoid any consequences for the technical staff. Usually, they should recognize it before writing a manuscript as one of the co-authors worked in the chemical department. Unfortunately, we can provide a link on this paper with the purpose of keeping the reviewing process anonymous.

We suppose that nowadays people spend less time in the libraries when most of the published articles do not open access. Then we have a situation when some of the young scientists have no open sources for their research and can judge a manuscript only by an abstract.

We think that everyone should once think about what they want to combine as materials before experimenting with making their conclusions more clearly, e.g., on why they see bright sparks and dirty dust during electrical discharge machining of stainless steel with a brass tool.

We believe that our research published in the open-access journal can help the young and probably experienced authors to avoid these typical mistakes based on the absence of open knowledge. Furthermore, we would like to summarize a few studies on the electrical discharge machining of non-conductive materials. We kindly hope that the reviewer will find our idea exhaustive and helpful to make a decision on publishing the fully revised version of this manuscript.

References

1. Kumar Baroi, B.; Kar, S.; Kumar Patowari, P. Electric Discharge Machining of Titanium Grade 2 Alloy and its Parametric Study. Mater. Today Proc. 2018, 5(2), 5004–5011.
2. Selvarajan, L.; Sathiya Narayanan, C.; Jeyapaul, R.; Manohar, M. Optimization of EDM process parameters in machining Si3N4-TiN conductive ceramic composites to improve form and orientation tolerances. Measurement 2016, 92, 114–129.
3. Assarzadeh, S.; Ghoreishi, M. A dual response surface-desirability approach to process modeling and optimization of Al2O3 powder-mixed electrical discharge machining (PMEDM) parameters. International Journal of Advanced Manufacturing Technology 2013, 64(9-12), 1459-147
4. Prabu, M., Ramadoss, G., Senthilkumar, C., Boopathi, R., Magibalan, S. Experimental investigation on effect of graphite powder suspended dielectric in electric discharge machining of AL-TIB2 composites. Journal of Chemical and Pharmaceutical Sciences 2015, 7, 52-54
5. Ji, R.; Liu, Y.; Zhang, Y.; Wang, F.; Cai, B.; Fu, X. Single discharge machining insulating Al2O3stantaneous pulse energy in kerosene. Manuf. Process. 2012, 27(6), 676–682.
6. Rajamanickam, S., Prasanna, J., Chandrasekhara Sastry, C. Analysis of high aspect ratio small holes in rapid electrical discharge machining of superalloys using Taguchi and TOPSIS. Journal of the Brazilian Society of Mechanical Sciences and Engineering 2020, 42(2), 99.
7. Kumari, S., Datta, S., Masanta, M., Nandi, G., Pal, P.K. Electro-Discharge Machining of Inconel 825 Super alloy: Effects of Tool Material and Dielectric Flushing. Silicon 2018, 10(5), 2079-2099.
8. Mohanty, C.P., Satpathy, M.P., Mahapatra, S.S., Singh, M.R. Optimization of cryo-treated EDM variables using TOPSIS-based TLBO algorithm. Sadhana - Academy Proceedings in Engineering Sciences 2018, 43(4), 51.
9. Kumar, A., Abhishek, K., Vivekananda, K., Upadhyay, C. Experimental study and optimization of process parameters during wedm taper cutting. Advances in Intelligent Systems and Computing 2019, 817, 721-736.
10. Raju, L., Hiremath, S.S. Machining and Characterization of Micro-Channels Generated on Phosphor Bronze Using μ –EDM. Journal of Advanced Manufacturing Systems 2020, 19(1), 87-106.
11. Qi, Y.; Nguyen, V.; Melkote, S.; Varenberg, M. Wear of WC inserts textured by shot peening and electrical discharge machining, Wear 2020, 452-453, 203279.
12. Singh, M.A.; Joshi, K.; Hanzel, O.; Šajgalík, P.; Marla, D. Identification of wire electrical discharge machinability of SiC sintered using rapid hot pressing technique, Ceramics International 2020 (in printing).

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

I noticed that most problems have been addressed thus I recommend publication of the manuscript.

Reviewer 3 Report

The Authors have correctly addressed most of the suggestions raised during the peer-review process, the manuscript is now suitable for publication.

Reviewer 4 Report

Thanks to the authours for theirs work. Now the paper is suitable for publication.