Surface Quality of Metal Parts Produced by Laser Powder Bed Fusion: Ion Polishing in Gas-Discharge Plasma Proposal

Round 1

Reviewer 1 Report

The article is very interesting, touching and indicating many problems related to the production with the use of incremental methods, and thank you for bringing up these topics in the publication.

The authors in their article discuss the issues of finishing metal materials (different grades) produced with the use of additive methods very broadly and indicate their own experimental results (but I am not sure of it). The paper is a review type of paper what indicated that all discussed results should be found in specific papers.

The research focused on the 12kH18N9T steel for which it was indicated, roughness results (Fig. 4), or surface morphology (photo 5 lacks the scale - it is worth completing it). But the most of the paper authors indicate references to the works of other scientists, but do not refer all of them to specific works, e.g. in line 279-281 - The results obtained by various authors indicate that the bubble's symmetric collapse creates high-intensity fields of pressure (5 –10 thousand atm .) and temperatures (up to 2000 ° C) or line 339-341: In recent years, many researchers have been using the experimentally validated two-structure model. Considering the fact that the authors make analytical research and the article has mainly of a review nature, the discussion should include the analysis and discussion of the results of specific papers, and not a general nature of problem (except conclusions).

 The article reads well and is understandable, but the scientific factor is missing, which makes it mainly technical paper - especially up to the 610 line. Moreover, when analyzing the experimental data, it is not clearly indicated what is a direct result of the authors' own work, and what is taken from literature.

The proposed 3 title’ stages are purely theoretical (in my opinion) and do not necessarily have to bring the assumed end result - especially that the discussion is conducted for various material groups, starting from the general concept of metal through titanium and its alloys, cobalt, stainless steel, etc.

I recommend:

- supplementing the data from the literature with the indication of literature sources, e.g. lines 378-381.

- considering addition chapter titled for example “research/ analysis methodology” along with an indication of the material used in the analysis/ research / discussion and the methodology of research according to the process parameters and it effects, which will allow for a direct separation of the results of own analytical research (if shown in the work) from those referred to in the literature. Moreover, it allow to calculate the proposed values of parameters considering specific materials and its properties.

Author Response

Response to Reviewer 1 Comments

 

Dear reviewer,

Thank you very much for your high evaluation of our work and valuable comments. We have modified the manuscript according to them. Introduced changes were marked by green in the text of the manuscript.

 

Kind regards,

Authors.

 

Point 1: The article is very interesting, touching and indicating many problems related to the production with the use of incremental methods, and thank you for bringing up these topics in the publication. The authors in their article discuss the issues of finishing metal materials (different grades) produced with the use of additive methods very broadly and indicate their own experimental results (but I am not sure of it). The paper is a review type of paper what indicated that all discussed results should be found in specific papers.

Response 1:  Thank you once again for your kind evaluation of our work. We have tried to work in the field that is very important for the industry and, at the same time, is not enough covered with scientific research and publications.

We would add that the presented work is an analytical review and discussion on achievements in the proposed area. Our research group works on this topic since 2011, and we have noticed that the surface quality of complex-shaped parts produced with additive manufacturing method is critical for most industrial applications. Some of the presented results are based on our research projects and published work published before 2021. This paper aims to propose a new vision and approach in solving the problem of surface quality using the ion polishing method in gas-discharge plasma based on the conducted work and experience. We went further in our research within the discussion and have proposed three stages for ion polishing in gas-discharge plasma for parts produced by laser powder bed fusion.

Nonetheless, if the reviewer finds that touched material is excessive for the current publication and goes out of the review work, we are ready to revise it totally and remove everything related to our proposal on the ion polishing in gas-discharge plasma.

Point 2: The research focused on the 12kH18N9T steel for which it was indicated, roughness results (Fig. 4), or surface morphology (photo 5 lacks the scale - it is worth completing it). But the most of the paper authors indicate references to the works of other scientists, but do not refer all of them to specific works, e.g. in line 279-281 - The results obtained by various authors indicate that the bubble's symmetric collapse creates high-intensity fields of pressure (5 –10 thousand atm .) and temperatures (up to 2000 ° C) or line 339-341: In recent years, many researchers have been using the experimentally validated two-structure model. Considering the fact that the authors make analytical research and the article has mainly of a review nature, the discussion should include the analysis and discussion of the results of specific papers, and not a general nature of problem (except conclusions).

Response 2: We have chosen this steel as one of the most demanding in the aircraft industry. Both of the figures present our results for chrome-nickel steel of our previous research work series. We have added some additional pictures that were never published before. Figure 5 (now it is Figure 7) was modified according to the recommendations (the scale is added).

In our own work, we try to reduce using figures of published works that were presented by other authors to avoid copyright issues and use only original figures or figures published in our own works.

The fragment on bubble collapse during cavitation abrasive finishing is revised, and two additional references are added.

The fragment on the two-structure model of high water is revised, and additional references are added.

We tried to follow the recommendations on making an analytical article and we hope that, in the current version of the manuscript, our idea is clearly presented for potential readers of the journal.

Point 3: The article reads well and is understandable, but the scientific factor is missing, which makes it mainly technical paper - especially up to the 610 line. Moreover, when analyzing the experimental data, it is not clearly indicated what is a direct result of the authors' own work, and what is taken from literature.

Response 3: All the data with no analytical character are not our direct results and were taken from the published papers since the presented article is a critical and comprehensive review of the current surface quality problem. It covers all possible methods to improve surface quality steel parts produced by laser powder bed fusion. Some of these methods are underestimated (such as ultrasonic plastic deformation) when other methods were never proposed for the complex parts produced by additive manufacturing. The scientific factor is in the scientific proposal of technical principles and general conception of ion polishing in gas-discharge plasma.

We would like to add that there are two types of review writing. One of them is to list all scholars in the subject area who have publications on the topic. Our research team sometimes writes detailed reviews like this. If you pay attention to the works that have been reviewed and published in various journals in recent years, you will notice that the review comes down to listing all those involved in the topic of research, without a built-in logic of storytelling, which significantly reduces the overall impression of the article. The second type of review is aimed at identifying the motives of the research, where the main idea of ​​the article, aimed at solving a specific scientific and technical problem, which has a fundamental and quantifiable result for the industry, where references to literature sources are only intended to support the developing thought of the authors and lead to specific and countable conclusions.

Point 4: The proposed 3 title’ stages are purely theoretical (in my opinion) and do not necessarily have to bring the assumed end result - especially that the discussion is conducted for various material groups, starting from the general concept of metal through titanium and its alloys, cobalt, stainless steel, etc.

Response 4: Thank you, it is revised.

Point 5: I recommend:

- supplementing the data from the literature with the indication of literature sources, e.g. lines 378-381.

Response 5: Thank you for your kind suggestion. We have some doubts on this fragment since in the mentioned 4 lines 2 references were provided:

“this case, complete passivation occurs and the transition of the surface layer of the metal from the active state to the passive state, at which the process of anodic dissolution stops [92].

Prof. A.M. Chirkov and his colleagues proposed to solve the problem roughness of additively manufactured parts using the laser-plasma polishing of a metal surface [93]. They are ignited in metal.”

Thus, we have added a reference in the previous fragment:

“Under certain conditions, an increase in the current density relative to its optimal value can lead to the formation of oxide films of a complex composition, which do not dissolve during classical electrolysis [96]. The complete passivation occurs and the transition of the surface layer of the metal from the active state to the passive state, at which the process of anodic dissolution stops [97]. The pH of the used electrolyte in electrochemical abrasive polishing of cobalt influences the thickness of the complex oxide film: the thickness increases when pH is varied in the range of 5.0 – 8.0 and decreases when pH is 8.0 – 9.0 combined increased wear [98].”

Point 6: - considering addition chapter titled for example “research/ analysis methodology” along with an indication of the material used in the analysis/ research / discussion and the methodology of research according to the process parameters and it effects, which will allow for a direct separation of the results of own analytical research (if shown in the work) from those referred to in the literature. Moreover, it allow to calculate the proposed values of parameters considering specific materials and its properties.

Response 6: Thank you for your kind suggestion that we highly appreciate. We have added a new chapter combined with the material we have already and new statements on research methodology. The article was reorganized according to the reviewer’s comments, and we hope that the reviewer will find the current form more suitable for publication according to his kind and valuable comments.

Author Response File: Author Response.docx

Reviewer 2 Report

This manuscript reviews current post-processing methods of laser additive manufactured parts and provides an innovative approach for finishing laser additive manufactured parts based on gas-discharge plasma, which is well-organized and is of interest to the readers of the journal. It is recommended for publication in Technologies. 

Author Response

Response to Reviewer 2 Comments

Dear reviewer,
Thank you very much for your kind evaluation of our work, and we wish you much success in all your current research projects.

Kind regards,
Authors.

Reviewer 3 Report

Dear Authors, I recomend following corrections:

1) line 53, stimulating

2) Fig. 3, line 190, Fig. 5, line 276, Please, change the grade of steel (12kH18N9T) on 12Cr18Ni9Ti steel,

3) Line 259-260, line 320-321. Delete the space.

4) Fig. 5, Please, add the scale on the images.

5) Line 278, change the magnification value to ×300

6) Line 429. Please, add reference not only on the patent, but onthe paper in the research journal including the mentioned installation description, e.g. Teresov, A.D., Ivanov, Yu.F., Petrikova, E.A., Koval, N.N. Structure and Properties of VT6 Alloy Obtained by Layered Selective Sintering of a Powder // Russian Physics Journal, 2017, Vol. 60, No. 8, pp. 1367–1372.

7) Fig. 8. I think that there is not one post-processing, it is laser and electron-beam polishing. Please, add it or write, why it is not?

Author Response

Response to Reviewer 3 Comments

Dear reviewer,

Thank you very much for your high evaluation of our work and valuable comments. We have modified the manuscript according to them. Introduced changes were marked by yellow in the text of the manuscript.

Kind regards,

Authors.

 

Point 1: line 53, stimulating

Response 1:  Thank you, corrected in text: “In most cases, it can be determined by developing the scientific and technological principles of post-processing based the analytical and experimental research.”

Point 2: Fig. 3, line 190, Fig. 5, line 276, Please, change the grade of steel (12kH18N9T) on 12Cr18Ni9Ti steel,

Response 2: Thank you, modified in the text as follows: 12Cr18Ni9Ti austenite chrome-nickel stainless steel (analog of AISI 321).

Point 3: Line 259-260, line 320-321. Delete the space.

Response 3: Thank you, modified in the text as follows: 2000°C.

Point 4: Fig. 5, Please, add the scale on the images.

Response 4: Thank you, it is revised.

Point 5: Line 278, change the magnification value to ×300

Response 5: Thank you, it is revised.

Point 6: Line 429. Please, add reference not only on the patent, but onthe paper in the research journal including the mentioned installation description, e.g. Teresov, A.D., Ivanov, Yu.F., Petrikova, E.A., Koval, N.N. Structure and Properties of VT6 Alloy Obtained by Layered Selective Sintering of a Powder // Russian Physics Journal, 2017, Vol. 60, No. 8, pp. 1367–1372.

Response 6: The list of references is revised.

Point 7: Fig. 8. I think that there is not one post-processing, it is laser and electron-beam polishing. Please, add it or write, why it is not?

Response 7: We have revised Figure 8 and added data on laser ablation. If the reviewer thinks that we should also add electron beam polishing, we are ready to complete Figure 8 with an additional subfigure.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The paper is rebuild and some aspects are added what make the paper more valuable than previous version. The paper includes the concept of ion polishing method as the useful method for surface finishing steels i.e. for aircraft industry.

The work is, in my opinion, valuable review of the current statement of art and also includes some clues for interesting for reader.

In my opinion, the paper can be published in present form, but I am waiting for the test results of this concept.

The chapter of research methodology is added (after reviewer recommendation), but in my opinion it is the weakest part of the paper – it’s just to genetic. The figure 2 shows more in research methodology (I like it very much!, and I will present it on my classes after publication) then point 2.2.

 

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

(Figure 1,b) Correct the units of measure of the axes from mm to µm.

(Lines 103 to 107) It is recommended to review the relationship between Ra and H_a. It is not clear what is the origin of this relationship and how it relates to Figure 3.

(Figure 3) It is recommended to review the image in the figure and in particular the positioning of "Ra", as it is not possible to understand what it refers to.

Author Response

Response to Reviewer 1 Comments

 

Dear reviewer,

Thank you very much for your kind evaluation of our work. We do agree with all your proposals and comments and have modified the manuscript according to them.

Introduced changes were marked by yellow in the text of the manuscript.

 

Kind regards,

Authors.

 

Point 1: (Figure 1,b) Correct the units of measure of the axes from mm to µm.

Response 1: Thank you very much that you have noticed it. The correct unit is µm; the figure is revised.

Point 2: (Lines 103 to 107) It is recommended to review the relationship between Ra and Ha. It is not clear what is the origin of this relationship and how it relates to Figure 3.

Response 2: Thank you for your attention to the details. The equation is based on trigonometry identities. We have added an additional figure (3a) to make it more understandable and found a mistake in the mentioned equation.

The length of HC is equal to the multiplication of AC and cosα (the relevant figure is in the file). At the same time, OC is ½ of HC, then OC = ½AC·cosα. Since AC is the height of the layer, α is an angle of profile inclination, KE is the middle line, and then OC is the average height of roughness (Ra).

If the reviewer finds it suitable, we can introduce the relevant passage into the manuscript's text.

Point 3: (Figure 3) It is recommended to review the image in the figure and in particular the positioning of "Ra", as it is not possible to understand what it refers to.

Response 3: We have tried to revise it. We hope that the reviewer finds the current version suitable. Otherwise, we are ready to represent it in another way.

Author Response File: Author Response.pdf

Reviewer 2 Report

Ion Polishing in Gas-Discharge Plasma of Metal Parts Produced by Laser Additive Manufacturing has been studied in this paper. The topic is very interesting and relevant for the community. The authors reviewed one of the most important issues associated with laser additive manufacturing and available solutions but I would like to give few comments for publication.

1. Literature review is fair enough
2. Mass quotations like [3,4] should be avoided. Please link each statement in the text with the corresponding reference. In the case of mass citations, the assignment cannot be made.
   
   
3. The paper deals with a proposal for using ion polishing of laser AM parts to be used as a post-processing technique to reduce the surface roughness and increase the surface integrity where authors mentioned “The conducted analytical research proposes developing the application of one of the promising approaches in finishing the laser additively manufactured parts - ion polishing in a gas discharge plasma [92-96]. This technology was never proposed before processing parts after laser-based growing solids or for any other 3D-printing technology. Besides, it has strong advantages that improve operational ability and service life of the responsible surfaces”. I suggest the authors to support this statement using some experimental results.

Author Response

Response to Reviewer 2 Comments

 

Dear reviewer,

Thank you very much for your kind evaluation of our work. We do agree with all your proposals and comments and have modified the manuscript according to them.

Introduced changes were marked by green in the text of the manuscript.

 

Kind regards,

Authors.

 

Point 1: Literature review is fair enough

Mass quotations like [3,4] should be avoided. Please link each statement in the text with the corresponding reference. In the case of mass citations, the assignment cannot be made. 

 

Response 1: Thank you very much for your suggestion; we have modified the manuscript and applied your recommendation where it was possible. The discussion stayed as it is since it is quite challenging to summarize individual. Furthermore, for the passage over Figure 4, we have split citations into two groups – selective laser melting and laser cladding without slitting with the type of metals and alloys to avoid overloading of the text.

 

Point 2: The paper deals with a proposal for using ion polishing of laser AM parts to be used as a post-processing technique to reduce the surface roughness and increase the surface integrity where authors mentioned “The conducted analytical research proposes developing the application of one of the promising approaches in finishing the laser additively manufactured parts - ion polishing in a gas discharge plasma [92-96]. This technology was never proposed before processing parts after laser-based growing solids or for any other 3D-printing technology. Besides, it has strong advantages that improve operational ability and service life of the responsible surfaces”. I suggest the authors to support this statement using some experimental results.

 

Response 2: This paper does not show the experimental results but aimed to review science's state on existing post-processing methods and the last achievements. It is evident that additive manufacturing methods exhausted their potential until now and took their place in the production industry and market. Further development is hampered by the existing obstacles – the existing post-processing methods' inability to improve wear resistance of the complex-shaped functional surfaces. The conclusion that the proposed idea is known is proved by observing the last achievements in the post-processing of additively manufactured parts. However, we have planned to show the experimental results in further research since we are sure of the proposed idea's potential. We have added the relevant passages into the manuscript text.

 

Author Response File: Author Response.pdf

Reviewer 3 Report

 

The paper is a review paper.

In AM I recommend to use ISO / ASTM52900 – 15 Standard Terminology for Additive Manufacturing – General Principles – Terminology. For the sake of clarity and for future understandability and indexing when standard name overrules other.

The review is not very well structured. What is a common thread and what do you want to review? See example: Gustavii, Björn. How to write and illustrate a scientific paper. Cambridge University Press, 2017. Can be found free online.

When referring what others has done there is no need to mention institute, country etc. Makes text really hard to read. Those details can be found based on references. Example

“Researchers from the Vyatka machine-building enterprise Laser Technics and Technology LLC (Kirov, Russia) proposed to solve the problem roughness of additively manufactured parts using the laser-plasma polishing of a metal surface [85,86]”

In the other chapters there are parts that fit better in introduction – example leap jet engine story etc.

If this is a review there seems to be descriptions that would fit better in materials and methods? Is this are review or original article? Also in Author Contributions there is roles that does not fit in review article?

Literature part there should be more relevant references related to post processing AM parts especially related alternative post processing and comparison. Example references to read:

Frazier, William E. "Metal additive manufacturing: a review." Journal of Materials Engineering and Performance 23.6 (2014): 1917-1928.

Salmi, Mika, Juha Huuki, and Iñigo Flores Ituarte. "The ultrasonic burnishing of cobalt-chrome and stainless steel surface made by additive manufacturing." Progress in Additive Manufacturing 2.1-2 (2017): 31-41.

“Additive Joins Subtractive on Advanced All-in-One Machines." Manufacturing Engineering 152.4 (2014): 67-69.

 

How the review was performed? What databases were used and which keywords? Was there a structed way of doing that or just a random?

 

I recommend Major revision for the paper to see more about the details and novelty of the submission.

Author Response

Response to Reviewer 3 Comments

 

Dear reviewer,

Thank you very much for your kind evaluation of our work. We do agree with all your proposals and comments and have modified the manuscript according to them.

Introduced changes were marked by blue in the text of the manuscript.

 

Kind regards,

Authors.

 

Point 1: In AM I recommend to use ISO / ASTM52900 – 15 Standard Terminology for Additive Manufacturing – General Principles – Terminology. For the sake of clarity and for future understandability and indexing when standard name overrules other.

Response 1: Thank you much for your suggestion. We have double-checked the used terminology in the manuscript according to the mentioned ISO standard https://www.astm.org/Standards/ISOASTM52900.htm. If the reviewer points us the particular fragment where it can be improved, we will update the mentioned fragment with much pleasure.

Point 2: The review is not very well structured. What is a common thread and what do you want to review? See example: Gustavii, Björn. How to write and illustrate a scientific paper. Cambridge University Press, 2017. Can be found free online.

Response 2: Thank you very much for your kind suggestion. B. Gustavii is a known author who has been teaching courses in scientific writing for doctoral (Ph.D.) students in medicine for more than 25 years, and he brings his personal experience to the books he has written. He wrote more than 100 scientific papers (H-index) and even worked as a journal editor. However, his impact on the science state was more extensive than his metrics in the international citation system.

However, his book is full of terms related to medicine and far for manufacturing, metals, and production. Some of his sentence structures can be used indeed for preparing the manuscripts in technology. However, we do not agree with some pictures, as presented in Figure 23.1. We think that we should not pre-demonize editors since they are friendly people who do their work great and help to improve the manuscript. We would like to point out that some of our authors also has impressive experience in writing scientific papers and reviews:

Authors	H-index in Web of Science	ResearcherID Web of Science	Published papers in the journals, included in Web of Science	Editorship
Prof., Dr. in Eng. Sci., Sergey N. Grigoriev	26	AAF-8027-2019, J-2463-2012, AAF-8027-2019,	205	Coatings, Metals (2019-2020), Mechanics and Industry (2015-2017), Material Science Forum (2015,2016)
Prof., Dr. in Phys. and Math. Sci., Alexander S. Metel	17	L-8736-2013	81	-
Doc., Dr. in Ph. (Eng. Sci.), Marina A. Volosova	15	B-3020-2013	126	Metals (2019-2020), Mechanics and Industry (2015-2017), Material Science Forum (2015,2016)
Dr. in Ph. (Phys. and Math. Sci.), Yury A. Melnik	12	C-3193-2011	52	-
Dr. in Ph. (Eng. Sci.), Anna A. Okunkova	11	B-3358-2013	50	Metals, Mechanics and Industry (since 2015); constant reviewer for Materials (Q1-2), Material and Design (Q1)
Mr. Pavel A. Podrabinnik	5	T-6980-2017, U-5447-2019	18	-
Mr. Enver Mustafaev	1	AAD-2983-2019	5	-

However, I have found a few interesting suggestions for a review paper in the recommended manual:

1) A review article can, however, have a title ending with a question mark, because some papers reviewed say one thing; others, the opposite. The title of a mini-review published in Nature (Pitnick et al. 1995) presumably covering all or most facets of the debate is, for example: How long is a giant sperm? (Page 50) – We would like to stay as it is if the reviewer agrees with it.

2) I advised the author to open the introduction with the third sentence. The reference (1) should be to a carefully chosen review article describing the problem. You probably need more than two or three sentences for your introduction, but it should preferably not exceed one page in length (typed double-spaced). More space may be required for certain topics, such as occupational science, medical ethics, and nursing and health care. Check the current version of the Instruction for Authors. (Page 62) – We did our best.

3) The common subtitle “A review of the literature” is inappropriate, because a case report is too brief (usually only two pages of running text) to permit even a mini-review. Couldn’t the young author (it often is a junior) write a review article separately? No, an acknowledged expert should write the review, often after an invitation. He or she is supposed to have the experience to evaluate the articles, emphasize the good ones, merely mention others, and, above all, have the courage to exclude works that are below standard. Reviews may include hundreds of references and are often used when you have to limit your bibliography – and you must be able to rely on them. (Page 103) – We tried to follow this suggestion: this review is invited, we have a solid team, and our reference list is more than 100 positions.

Point 3: When referring what others has done there is no need to mention institute, country etc. Makes text really hard to read. Those details can be found based on references. Example “Researchers from the Vyatka machine-building enterprise Laser Technics and Technology LLC (Kirov, Russia) proposed to solve the problem roughness of additively manufactured parts using the laser-plasma polishing of a metal surface [85,86]”

Response 3: Thank you. The text is revised.

Point 4: In the other chapters there are parts that fit better in introduction – example leap jet engine story etc.

Response 4: Thank you for this suggestion. We have tried to improve it.

Point 5. If this is a review there seems to be descriptions that would fit better in materials and methods? Is this are review or original article? Also in Author Contributions there is roles that does not fit in review article?

Response 5: It is a review. If you find a section with the description of the more relevant passages for the section of materials and method, we kindly ask to point it for revising. The contributions of the authors are revised, thank you for pointing it.

Point 6: Literature part there should be more relevant references related to post processing AM parts especially related alternative post processing and comparison. Example references to read:

Frazier, William E. "Metal additive manufacturing: a review." Journal of Materials Engineering and Performance 23.6 (2014): 1917-1928.

Salmi, Mika, Juha Huuki, and Iñigo Flores Ituarte. "The ultrasonic burnishing of cobalt-chrome and stainless steel surface made by additive manufacturing." Progress in Additive Manufacturing 2.1-2 (2017): 31-41.

“Additive Joins Subtractive on Advanced All-in-One Machines." Manufacturing Engineering 152.4 (2014): 67-69.

Response 6: Thank you very much for your suggestion. We can use two of provided references for research in the field of post-processing methods of additively manufactured parts. However, we cannot refer them right due to ethical issues since any of the provided references can be related to the reviewer's publications.

The last article has no data even on abstract and no reference list registered in Web of Science and even absent in the open research bases. We had the impression that the article is not scientific but has editorial or publicity character. The author of this publication has such a large field of interest including COVID and additive manufacturing that we have doubts on citing him. His articles https://www.sme.org/technologies/articles/2020/august/covid-19-disrupts-planning-not-advanced-technology/ have definitely non-scientific character but some kind of media with not numbered figures, pictures have more social character than informative, no references; it does not have even any conclusions or any discussion on proposed research subject. Thus, we hesitating on citing non-scientific material in such high ranked scientific journal as Metals.

At the same time, Frazier, William E. Metal Additive Manufacturing: A Review. J. Mater. Eng. Perform. 2014, 23, 1917-1928 is cited already 1608 times. Moreover, in the Web of Science, you can find at least 471 articles with the same topic, including 105 articles published in 2020. We have tried to concentrate more not on metal additive manufacturing in common since there is more than enough works, most of them since the last three years already have lost their actuality but on post-processing methods that have not been enough researched staying deprived of attention from the scientific community. It can be proved by only 7( !!!) articles devoted to the post-processing methods of additively manufactured parts this year and 29 articles in total.

Prof. Salmi's article deserves attention in further research since it is in open access and has many interesting passages and conclusions. Thank you!

Point 7: How the review was performed? What databases were used and which keywords? Was there a structed way of doing that or just a random?

Response 7: We are afraid that these questions are out of the field of competences required for the scientific publication. This kind of data is required to be mentioned in such works as reports on patent research. There we are obliged to mention used search tools and keywords. We would notice that all referred articles are presented and can be easily found in Web of Science. Mentioned patents can be found with the open research tools. The way of the search was structured – we had a defined research subject, grounded actuality of the conducted work (a red line in the Introduction, if we can say), formulated scientific tasks, and novelty.

Point 8: I recommend Major revision for the paper to see more about the details and novelty of the submission.

Response 8: Thank you very much for your kind evaluation. This analytical research's scientific novelty is determined by an overview of finishing methods and their influence of functionality and operation ability of the product responsible surfaces, and that are still not fully and completely overviews, by the proposal of using ion polishing in gas-discharge plasma for finishing and theoretical development of three stages of detailed post-processing for the first time.

Author Response File: Author Response.pdf