Electrochemical Behavior of Nickel Aluminide Coatings Produced by CAFSY Method in Aqueous NaCl Solution

Round 1

Reviewer 1 Report

This manuscript provides the detailed characterization of Ni-Al coatings produced by CAFSY method in NaCl solution. An extensive range of literature was reviewed to justify the need for this research. The experimental section is clear and reproducible. It was concluded that Ni-Al coatings produced by the CAFSY method exhibit similar electrochemical behavior to those produced by the traditional methods with pre-alloyed powders. The conclusions were drawn from the experimental observations and it definitely expanded the current knowledge on this topic. However, the manuscript is too long, and thus, will lose the attraction needed by the readers. The followings need to be addressed before accepting the manuscript:

1. A lot of grammatical errors are present in the manuscript. It started from the abstract (line 10-- "[resent" should be "present") and throughout the manuscript it has used different fonts, styles etc. even some traces from the track changes appear in the manuscript. Please go through English Editing.

2. line 64-74: Do we need these simple basic equations?

3. Line 110: Please write a narration and FULL form of COMPO, DIST, SUBTEM, and COATR. Also, please explain why Table 1 starts with COMPO 5. What happened to COMPO 1-4? The same for COATR. Why do they start from 5 instead of 1?

4. Figure 1: Please remove the red underlined marks from NiAl.

5. Line 206- Fig.3α should be Fig. 3a.

6. There is a mixture of Fig. and Figure throughout the text. Please use only one format.

7. Lines 589-601: "Ahn et al [48] have claimed that chloride catalyzes the ejection of cations from the barrier layer/electrolyte interface leading to an increase in the cation vacancy concentration in the passive film and, hence, breakdown of passivity. The bi-layered structure of the passive film of Al is long known [49]. According to Bockris et Kang [50], the outer layer consists of Al-oxide, hydrated alumina and fibril-like AlOOH. The inner layer is mainly composed of Al2O3 with small amounts of fibril AlOOH. According to Zamazande, Bockris and Rosalbino, oxides of alloying elements (such as Cr, Ta, Si, Ge) may benefit localized corrosion resistance of Al and Fe-aluminides by blocking the Cl- adsorption sites [50-52]. The presence of transition metals (TM), such as Cr [51, 53-55], W [56-58], Mo [56-57], Ta [56, 59] etc. in the Al2O3-based passivating layer reportedly improves the localized corrosion resistance in Cl- containing solutions [60]."

All these are redundant. Please remove them from the result section. They can be in the introduction section not in the results section.

8. Lines 622-628: They are redundant. Please remove them.

Author Response

We would like to thank the reviewer for the very useful suggestions regarding the review of our paper. We have tried to conform to every single one of them. Please, find attached the revised manuscript, where the modifications are highlighted by a light-blue color, as well as they are marked up using the “Track Changes” function, “All-markup” sub-function.

Author Response File: Author Response.pdf

Reviewer 2 Report

The article discusses the electrochemical behavior of Ni-Al coatings produced by CAFSY method in aqueous NaCl solution. In my opinion, this article largely repeats the previously published article by Int. J Self Propag. high temp. Synth. 24, 192–202 (2015) https://doi.org/10.3103/S106138621504007X by the same author. In fact, this article is autoplagiarism. As I see it, based on the data presented in the photo, these studies were carried out in 2012 - 2015 and for the most part previously published. Accordingly, I do not consider it possible to republish previously published materials.

I also found a number of shortcomings of this article, which I give below:

Abstract: In this work we [resent results for... typo?

"CAFSY is a novel, cost-efficient and on-site-applicable..." - more like an advertising slogan, not part of a scientific article!

"under optimized conditions..." - which ones?

In general, the Abstract is extremely vague and is more of an advertising character. This is more acceptable for an advertising booklet, but not for a scientific pack. I recommend redoing the Abstract, focusing on: - The objectives of the study and - The results of the study (in a specific form, and not in the categories of "best", "effective", "optimal", etc.).

It is not clear why it is necessary to provide data on the reaction formulas (1-11) - how they help in the future. If the authors consider it necessary for the reader (I'm not sure about this), then at least they should be correctly referenced: (2) or (3,4,5).

Figures 1,3,5,7. How do the Authors distinguish between the different factions in the image? An appropriate EDS, preferably SAED, must be performed in order to identify NiAl, NiAl3, Ni2Al3 and Ni3Al. But I don't see this data!

Figures 1,3,5,7. Judging by the dates on the pictures, these photos were taken in 2012-2013! 10 years ago!!! It has never been used in other articles in the past 10 years ? Waiting for "their hour"?

Figure 12. These photos are a little younger - taken in 2015! When were these studies carried out? How new and original is this data?

Figure 12. How was the EDS analysis done? What is the size of the study area? These areas must be marked on the image!

Conclusions also include a discussion. It is not right.

References do not meet the requirements of the publisher.

The article looks like self-plagiarism. At least a number of drawings repeat the article https://doi.org/10.3103/S106138621504007X

I believe that such reuse of old materials previously published is unacceptable!

Comments for author File: Comments.pdf

Author Response

We would like to thank the reviewer for the very useful suggestions regarding the review of our paper. We have tried to conform to every single one of them. Please, find attached the revised manuscript, where the modifications are highlighted by a light-blue color, as well as they are marked up using the “Track Changes” function, “All-markup” sub-function.

Author Response File: Author Response.pdf

Reviewer 3 Report

Dears Authors,

Generally, the work is good and the results are interesting. The research methods selected by the authors are adequate for the subject of the paper.

Please add the results of XRD studies and reference numbers conforming to JCPDS/ICDD files.

Lines 255-257, Figure 11., Line 415, 425 - Please improve grade C

Please correct the figure - it is illegible.

At SEM cross-section and EDS, we cannot measure oxygen. Please correct these results.

Conclusions 2 and 3, on what basis they were saved? Please enter specific values.

Where are the test results? Please give me a method to measure porosity in coatings.

The topic of the paper is very interesting and worth publication.

I recommend the article for publication after a minor revision.

Regards

Author Response

We would like to thank the reviewer for the very useful suggestions regarding the review of our paper. We have tried to conform to every single one of them. Please, find attached the revised manuscript, where the modifications are highlighted by a light-blue color, as well as they are marked up using the “Track Changes” function, “All-markup” sub-function.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The reviewer is satisfied with the response from the authors

Author Response

We would like to thank the reviewer for the useful suggestions regarding the review of our paper. Please, find attached the revised manuscript

Thank you

Reviewer 2 Report

The authors made a number of corrections to the manuscript, improving its quality. But I highly recommend the author:

1. At least remove the date (2011, etc.) from the photo (it's easy to do).

2. I still consider it unacceptable to use photos that have previously been used in other articles (or at least you need to give the appropriate reference).

Author Response

We would like to thank the reviewer for the useful suggestions regarding the review of our paper. Please, find attached the revised manuscript.

Thank you

Author Response File: Author Response.pdf