Abrasive and Erosive Wear of TI6Al4V Alloy with Electrospark Deposited Coatings of Multicomponent Hard Alloys Materials Based of WC and TiB2
, Mara Kandeva 2, Valentin Kamburov 2, Antonio Nikolov 2 and Rayna Dimitrova 2Round 1
Reviewer 1 Report
The topic of the article is quite interesting. It provides novel information on the choice of the best material for the electrode for depositing spark-coating. The results show the feasibility of this technology in improving the wear resistance of Ti-based alloys. However, the structure of the coating is poorly studied. The authors should use high-magnification SEM/EDS analyzing the structural components and elemental distribution within the coating. It will help to improve the scientific value of the article.
The other comments are:
1. The image in Fig.2d is blurred. It should be replaced by the better one.
2. Fig.3 does not contain the scale bar. The images of the microstructure are of too low magnification, it is difficult to reveal the structural features. It is advised to replace them with SEM images of much higher magnification.
3. Where was the coating microhardness measured: on the top of the coating or in a cross-sectioned specimen? This should be added to the Methodology.
4. XRD pattern (Fig. 4b) does not contain the labels of the phases. Please add them.
5.. The axes of XRD patterns (Fig. 4) are too small and not readable.
6. The section “Discussion” should be added to substantiate the results obtained.
7. The authors mentioned the “amorphous-crystalline structures”, but they did not present compelling evidence of the amorphous status. The broadening of XRD peaks can be connected with other structural reasons (dislocations, residual stresses, etc.).
8. What phases are in an amorphous state?
9. The introduction is short. Please avoid the combination of many references in one brackets ([3-14]), and pay some attention to them to reveal their significance for the topic.
Author Response
Please see the attachment
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The aim of the work should be more distinctly formulated. It is of particular importance the choice namely of Ti6Al4V alloy should be accented. Shear strength and wear resistance are vulnerable properties of this alloy to be used especially as biocompatible material. The influence of these coatings on the above properties of this alloy is of an especial interest.
I believe that Introduction should be improved by comparing the influence of any coatings independently of the methods of deposition on the above properties of Ti6Al4V alloy.
Scientific language have to be corrected. The roughness, uniformity, homogeneity and even pores have not any point of view (line 200).
Under conditions (line 348)
Lines 206-207 …the surface micro hardness increases 2-4 times compared to that of the titanium matrix. I believe that it is really trivial fact. The more interesting thing is adhesion to substrate and erosion wear.
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Reviewer 3 Report
The current paper reports the wear behaviour of electrospark deposited hard coatings on Ti6Al4V alloy. The writing style is poor with not enough results and poor quality SEM images. A number of times, the authors claims are not presented/supported by experimental proof. There is hardly any scientific explanation/mechanism beyond some experimental data which are not even adequate. Based on that, I recommend major revision of the manuscript. The specific comments are as follows:
1. The paper require a moderate revision from grammar and language point of view.
2. The title can be revised and concise. It will be “Ti6Al4V” instead of “TI6AL4V”.
3. Line 4: “TiB2” instead of TIB2.
4. Abstract: It should be written in past tense. Why there is division sings in line 19, 20?
5. Better to use full form of the terms before using abbreviation in the abstract.
6. The introduction sections needs to be improved by stating the foreseen advantages of the proposed coating system and justification of it.
7. The writing style is really poor and hard to follow. For example, the last paragraph of the introduction section is 9 lines long in 1 sentence!
8. Were the electrodes manufactured in-house or procured commercially. Details should be mentioned on that.
9. Line 99-100: Does not make much sense!
10. Better to include the image of the tribological apparatus as it is hard to follow from the description.
11. There are no scale bars in most of the SEM images.
12. The cross-section images should be taken in much higher magnification to reveal any reasonable microstructure of the coatings.
13. Fig. 4b should be indexed.
14. Does the measurement of coefficient of friction took the contribution of the running -in phase or not? Should be stated clearly.
15. Fig. 5: SEM figures should be in much higher magnification as no deformation in the coatings are noticeable in this low magnification.
16. There is little to no scientific explanation regarding the presented results. The presentation of only data does not provide enough merit to the paper to get published.
17. Post SEM images after the wear test must be included to reveal the coating degradation mechanisms with proper scientific explanation to support the findings.
18. The conclusion section should start with a paragraph before heading to the pointed conclusion.
19. The authors may include the following papers:
(i) https://doi.org/10.1016/j.wear.2006.03.026
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Reviewer 4 Report
1. After each terminology firstly appear in this paper, it necessary to explain, for example Ra, δ, Hv.
2. “with sizes 12×12×4 mm” was changed to “with sizes 12×12×4 mm3”
3. What is the “2÷4 times”? The same situation occurs elsewhere in this paper.
4. The authors declared that “Higher values were measured in ESD with the KW10T10B10 electrode, but the differences in the micro hardness values of the coatings from the two electrodes are relatively small. With an increase in the pulse energy, a tendency towards an increase in the micro hardness is also noticed.”. Why?
5. One suggestion, “coefficient of friction” and “friction coefficient” was used in this paper. Which is right? The same situation (KW10T10B10 and KWW10T10B10 in Figure) occurs elsewhere in this paper.
6. Pay attention to superscripts and subscripts on proper nouns or symbols. For example, TiB2
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Reviewer 5 Report
Dear Authors,
the manuscript entitled "Abrasive and erosive wear of TI6AL4V alloy with electrospark deposited coatings of multicomponent hard alloys materials based of WC and TIB2" by Todor Penyashki and co-workers discusses the use of different coatings applied on titanium surface to reduce the abrasive and erosive wear. The article presents the results of experimental studies of wear, surface roughness, microstructure as well as microhardness for titanium substrate and two types of elecrodes. I appreciate the contribution that the Authors made in preparing the experiment and manuscript. However, in my opinion the manuscript needs to be improved in some fields and some general remarks as well as the specific comments are bellow.
Evaluation of the paper, general remarks:
- Please add full affiliation and email addresses for all Authors of the manuscript.
- The Abstract section should present quantitative results and not only the most important qualitative results and/or generic considerations. Therefore, significant improvements are expected in this section of the manuscript.
- In the first chapter of the manuscript, the Authors have written in line 31:"Currently, various methods and means of applying coatings are offered - electrochemical, galvanic, thermochemical, vacuum, electrophysical, etc. [3-14],...". First of all, please look at the Instructions for Authors on how to describe literature in a manuscript (it should be [3–14]). Second, this sentence refer to 12 articles at once. It makes sense to describe in detail these articles if they are important to the research presented by the Authors in the manuscript.
- In line 50, the Authors use the personal form ("… but they do not always provide..."). This is not correct in high-quality articles. It suggests modifying this part of the article. Please check the entire article in terms of personal form.
- How many samples were used during the implementation of the study? The question is legitimate from the point of view of the reproducibility of the research and the obtained results.
- What is the accuracy of the mass measuring instrument? Please on the wear charts add the measurement uncertainty in the form of error bars. Without this information, it is difficult to clearly discuss the differences in wear for the different coatings (comment applies to Figure 6, 7, 8 and 9).
- Please add a view or diagram of the wear test bench in the section describing the test methodology.
- In the “3. Results” section, Authors present their results but without any discussion supported by the literature. When the results are not discussed and conveniently supported by the open literature, questionable conclusions are obtained. Currently, the article looks more like a report from wear research than a scientific article. Significant improvement in the description of the test results is required.
- Where is the Author contribution? Please add this information to the revised version of the manuscript.
- Please read the instructions on how to describe the references at the end of the article in the Authors' guide and change it. Currently, the references at the end of the text are not in line with the journal requirements. Journal title should be written by italic font and the year - bold.
- General language comment. The article is difficult to read due to the use of compound sentences in many places. An example is the description of the goal of the study. I ask that the Authors perform extensive linguistic proofreading to refine the text. It will then be easier to read.
Specific remarks/editorial comments/typos:
- line 65 - why does a sentence start with - ?, please remove these hyphens from the revised version of the manuscript.
- line 124 - please add the numbering of the formulas included in the manuscript.
- line 152 - Figure 1 caption - please adapt the figure caption (text formatting) to the requirements of the journal and the instructions for authors. Remark applies to all drawings in the text. Some of these drawings do not have a measurement scale (e.g. Figure 1a and 1b). In addition, the marking (a) and (b) should be under the figure and not on the figure - instructions to authors.
- for all Figure and Table captions the dot is missing at the end of the sentence.
- Where is Table 1 in the text?
- line 188 - Table 2 - the table style is not in line with journal requirements.
- line 219 - The scales on the figures are illegible, please enlarge them.
- line 349 - is CONCLUSIONS, should be Conclusions.
Article is interesting but the modifications should be implemented before considering the manuscript for publication. I hope these suggestions can help to improve the quality of this paper.
I wish you all the best.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors revised the paper properly.
Author Response
Dear Reviewer,
Dear Editors,
We, the authors, thank the reviewers for highlighting the shortcomings, errors, and omissions and for recommendations for improvement of the quality of the manuscript.
Thank you for accepting the revised manuscript.
We gratefully accept all your comments and recommendations. The manuscript has been restructured again according to your comments and recommendations, and all the errors, omissions, and shortcomings you pointed out have been taken into account and corrected.
Reviewer 3 Report
Can be accepted in current form.
Author Response
Dear Reviewer,
Dear Editors,
We, the authors, thank the reviewers for highlighting the shortcomings, errors, and omissions and for recommendations for improvement of the quality of the manuscript.
Thank you for accepting the revised manuscript.
We gratefully accept all your comments and recommendations. The manuscript has been restructured again according to your comments and recommendations, and all the errors, omissions, and shortcomings you pointed out have been taken into account and corrected.
Reviewer 4 Report
NO
Author Response
Dear Reviewer,
Dear Editors,
We, the authors, thank the reviewers for highlighting the shortcomings, errors, and omissions and for recommendations for improvement of the quality of the manuscript.
Thank you for accepting the revised manuscript.
We gratefully accept all your comments and recommendations. The manuscript has been restructured again according to your comments and recommendations, and all the errors, omissions, and shortcomings you pointed out have been taken into account and corrected.
Reviewer 5 Report
Dear Authors,
The article has been significantly improved in accordance with the remarks. However, not all comments have been taken into account.
- please check the whole text for different fonts, such as the abstract line 18,19,23 and others,
- this is a remark for references, in the instructions for authors it says: "References should be numbered in order of appearance and indicated by a numeral or numerals in square brackets-e.g., [1] or [2,3], or [4-6]." Why the authors did not follow the suggestions and requirements of the journal - line 32,33,39 and others, please in the next version of the manuscript take this into account,
- line 54 - is "...surfaces[18-20]...". - should be surfaces [18-20],
- line 55 - "...because they allow using...". - personal form, please change it,
- line 71 is blank, please remove it,
- equation marks 3,4 and 5 should be aligned to the right and equations centered,
- Fig. 1 - there is a) and b) - should be (a) and (b),
- Fig. 2. - incorrect labeling of the different parts of the figure,
- line 230 and 256 - there are two dots, please remove one,
- Fig. 4. - why are the figure captions (a) and (b) in the figure and not in the caption? please adjust the captions of the drawings to the requirements of the magazine, the same remark for figure 5.
I wish you all the best.
Author Response
Please see the attachment
Dear Reviewer,
Dear Editors,
We, the authors, thank the reviewers for highlighting the shortcomings, errors, and omissions and for recommendations for improvement of the quality of the manuscript.
Thank you for accepting the revised manuscript.
We gratefully accept all your comments and recommendations. The manuscript has been restructured again according to your comments and recommendations, and all the errors, omissions, and shortcomings you pointed out have been taken into account and corrected.
Author Response File: Author Response.pdf
