Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Micro arc oxidation, for the generation of a protective oxide coating layer, has been extensively applied to aluminum alloys and other metals over the last decade. There are several studies available that detail the effects of processing parameters on the various aspects of the coating(s) generated. While the current manuscript also highlights the effects of different processing parameters on the coatings’ properties, it is very difficult to justify the originality and significance associated with this work. This work unfortunately does not, in any way, extend the literature that is already available. Hence, I believe that this work might be suitable for another journal.

Author Response

Comments: Micro arc oxidation, for the generation of a protective oxide coating layer, has been extensively applied to aluminum alloys and other metals over the last decade. There are several studies available that detail the effects of processing parameters on the various aspects of the coating(s) generated. While the current manuscript also highlights the effects of different processing parameters on the coatings’ properties, it is very difficult to justify the originality and significance associated with this work. This work unfortunately does not, in any way, extend the literature that is already available. Hence, I believe that this work might be suitable for another journal.

Response: Thank you very much for your suggestions on my article. I have revised the article according to the requirements of other experts, and added the reasons for doing this research in the introduction. I look forward to your review and thank you again for your suggestions. (in the annex)

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The investigation examined the influence of electric parameters on the micro-arc oxidized film of aluminum foil under constant voltage mode. The study involved the variation of voltage, frequency, and duty cycle, and the analysis included measurements of thickness, pressure resistance, corrosion resistance, morphology, and phase composition. Therefore, the manuscript can be suitable for publication in the Journal of METALS. However, the reviewer wishes to provide constructive feedback and suggestions for further refinement of the manuscript.

1.      Brands of Feedstock materials are missing

2.      How do frequency and duty cycle parameters influence the thickness of the oxide film in micro-arc oxidation, and what is the optimal frequency and duty cycle for achieving a certain thickness of the oxide film?

3.      How do high voltage parameters influence the Rp (polarization resistance) and icorr (corrosion current) values in the kinetic potential polarization curves of aluminum foil specimens, and what is the relationship between them?

4.      How does the density and size uniformity of microporous apertures in the oxide film relate to the energy generated at high voltage, the repeated penetration through the thick oxide film, and the formation of dense and regular holes during the late stage of micro-arc oxidation?

5.      What are the differences in the cross-sectional morphology of the micro-arc oxidized film layer under low voltage and high voltage conditions, particularly in terms of layer thickness, stratified appearance, and the distribution of the inner and outer layers?

6.      How does X-ray diffraction analysis provide insights into the composition of the micro-arc oxidation film layer, particularly in terms of the dominant diffraction peak of Al, and how does this peak relate to the presence of different Al2O3 phases in the film layer?

Author Response

Please see replies in the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The article presents the results of research on the influence of electrical parameters on the formation and properties of oxide layers on aluminum.

 

In the overall assessment, the article is properly organized, but the discussion requires supplementation to maintain the appropriate scientific level.

 

Comments on the article:

 

Introduction describes the current state of knowledge with reference to References. However, there is no indication of the problem that requires solution and justification for undertaking this research. I believe that this information should be supplemented.

 

Procedures, materials and research methods have been sufficiently described.

 

Results and Discussion

The results of the coating thickness measurements should be specified as an average value with measurement error.

"Nacl" - should be NaCl.

 

Chapter 3.2: Discussion, in which the authors correlated the results of corrosion tests with the parameters and porosity of coatings is not documented with research results. It is required here to present research results documenting porosity. Or, better, discuss this correlation with the microstructure results.

Figure 2: The designation of the area from which the magnification is made is illegible.

 

In the overall assessment, the research results are presented as a research report. There is no proper discussion of the research results obtained in relation to the existing state of knowledge on this subject. The discussion should include a comparison of the research results obtained to alternative solutions and indicate why these results are important. I believe that this discussion should be supplemented to ensure the appropriate scientific level of the article for publication.

Author Response

Thank you very much for your comments and suggestions on my article, which is very helpful to me. Please see replies in the attachment, please check it. Thanks again for your suggestions.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

The authors provided a revised article and responded to all my comments.

 

The authors supplemented the article with their suggestions regarding the Introduction and discussion of the research results. They improved the quality of the figures and minor editing errors.

 

It is not clear to me why the authors think it is better not to include the measurement error for the average thickness values. It is obvious to me that the average value was calculated based on several measurements and it is obvious to calculate the standard deviation as well. But I leave the decision on this matter to the Editors.

 

It is also not clear to me why the authors changed the symbol of the corrosion current density from "Jcorr" to "Icorr" (Table 3). The symbol "I" is reserved for the current intensity, and the current density defines the current intensity per unit area according to the relationship J=I/S. Therefore, current density and current intensity are not the same, they have different units and are marked with different symbols.

 

Apart from that, I have no further comments and I think the article can be considered for publication.