Electrodeposition of Copper-Based Nickel–Graphene Coatings: Effect of Current Density on Microstructure and Properties
Round 1
Reviewer 1 Report
Comments and Suggestions for Authors1. The paper's structure is unconventional and confusing. The use of a "3. Results and Discussions" section followed by a separate "4. Discussion" creates significant redundancy. It is strongly recommended to merge these into a single, comprehensive "Results and Discussion" section and then add a dedicated "5. Conclusion" section to summarize the key findings and their implications, as the paper currently lacks a proper conclusion.
2. The calculation for thermal conductivity depends on density (ρ) and specific heat capacity (Cp), yet the manuscript provides no method for how these values were determined for the coatings. This is a critical omission that undermines the validity of the thermal conductivity results. The authors must describe how these parameters were measured or, if assumed, provide a clear justification.
3. The claim that the effect of current density has received "scant discussion" should be revised. The novelty should be more precisely framed around the comprehensive and simultaneous optimization of mechanical, tribological, corrosion, and thermal properties, which is a stronger and more accurate contribution.
4. The manuscript inconsistently refers to the carbon additive as "Graphene powder" and "graphite." Given the large particle size (7–10 µm), the authors should precisely define the material (e.g., graphene nanoplatelets, few-layer graphene) and use this term consistently throughout the paper for technical accuracy.
5. The discussion would be significantly strengthened by quantitatively comparing the key results (e.g., hardness of 284 HV, friction coefficient of 0.43) with values reported in the nickel-graphene literature cited in the introduction. This would provide essential context for the significance of the current work.
6. The introduction's literature review on Ni-Gr coatings is split into two separate paragraphs (lines 71-91 and 92-104); merging them would improve flow. Additionally, adding a brief introductory sentence at the start of each major section (e.g., after the "3. Results and Discussions" heading) would help guide the reader.
7. It would be good practice to briefly acknowledge that EDS has limitations for accurately analyzing light elements like carbon. Mentioning that other techniques (like Raman spectroscopy) could provide more definitive data on graphene quality would add depth to the analysis.
8. In Figure 10, the x-axis label "Cu" is inconsistent with the "Brass" substrate described in the text and tables. This should be corrected to "Brass" for consistency.
Author Response
Dear Reviewers,thank you very much for your constructive comments and valuable suggestions on our manuscript (Manuscript ID: [coatings-3969686], Title: [Electrodeposition of Copper-Based Nickel-Graphene Coatings: Effect of Current Density on Microstructure and Properties]). We have carefully considered all your comments and made corresponding revisions to improve the quality of the manuscript.In this revision, we have addressed every comment raised by both Reviewers 1 and 2 in detail. The responses are organized by reviewer (Reviewer 1 first, followed by Reviewer 2) and presented in the order of your original comment numbers . For each comment, we have clearly stated the revisions made, and marked the corresponding modified positions in the manuscript (e.g., Page X, Line X) for your convenience.Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe manuscript presents the experimental results on an important technological aspect of how current density influences the microstructure and properties of copper-based nickel–graphene (Ni–Gr) composite coatings prepared by electrodeposition. The optimal current density that balances mechanical, tribological, corrosion, and thermal performance was found and adequately described.
The topic is relevant and moderately original within the field of surface engineering and materials science. While nickel–graphene coatings have been studied before, this work properly emphasizes the systematic effect of current density as a critical parameter on multiple performance indicators.
Compared with existing literature, this study offers a comprehensive quantitative assessment of the effect of current density, linking structural evolution to functional performance. It integrates SEM, XRD, EDS, tribological, electrochemical, and thermal analyses in a unified framework, clearly identifying an optimal current density (2 A/dm²). That is good.
The conclusions are consistent with experimental evidence and logically address the central question. The data properly substantiates the correlation between microstructural refinement at 2 A/dm² and superior mechanical, corrosion, and thermal performance.
The references are comprehensive and mostly appropriate, covering studies on electrodeposition, nickel-based composites, and graphene-reinforced coatings.
The tables and figures are well-organized and clearly labeled, effectively illustrating trends in microstructure and properties. SEM and XRD images are especially helpful in visualizing grain evolution. Overall, the visual presentation is strong and effectively supports the narrative.
However, some improvements could be made:
The references provide solid theoretical and experimental context. Nevertheless, more recent references on hybrid coating systems and advanced electrodeposition modeling could enhance the theoretical foundation and broaden the contextual discussion.
The materials description in “2.1 Materials” is quite confusing: “the bras”, “copper alloy”; “copper plates” were used. Which one is true? Later, “brass” is used. In addition, Cu plate used in Figure 1. It would be useful to uniformize it.
What are the coating thicknesses in all electrodeposition cases?
Where can developed coatings be used in an industrial environment? Such discussions would strengthen the applicability of the results received.
Comments on the Quality of English Language
A native speaker should check the language. For example, in the introduction: “The results show that current density significantly influences coating properties…”, should be “The results show that current density during electrodeposition significantly influences coating properties…”, etc.
Author Response
Dear Reviewers,thank you very much for your constructive comments and valuable suggestions on our manuscript (Manuscript ID: [coatings-3969686], Title: [Electrodeposition of Copper-Based Nickel-Graphene Coatings: Effect of Current Density on Microstructure and Properties]). We have carefully considered all your comments and made corresponding revisions to improve the quality of the manuscript.In this revision, we have addressed every comment raised by both Reviewers 1 and 2 in detail. The responses are organized by reviewer (Reviewer 1 first, followed by Reviewer 2) and presented in the order of your original comment numbers . For each comment, we have clearly stated the revisions made, and marked the corresponding modified positions in the manuscript (e.g., Page X, Line X) for your convenience.Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe manuscript has been significantly improved and now presents a much stronger, clearer, and more compelling study. The authors have done an excellent job of addressing all the concerns raised during the initial review process. This work represents a valuable contribution to the field of composite coatings and surface engineering. The paper is now suitable for publication. However, there are a few minor typographical and consistency errors that are worth fixing before publishing.
On page 13, line 408, the heading for the "Thermal Conductivity" section begins with a stray letter 'F'. It currently reads: "F The variations in thermal conductivity..." This 'F' should be removed.
On page 10, line 314, the sentence reads: "The Vickers hardness of the Ni-Gr coatings initially tend to increase..." Since the subject is "The Vickers hardness" (singular), the verb should be "tends". The sentence should be corrected to: "...initially tends to increase..."
Throughout the manuscript, the unit for corrosion current density is presented in slightly different formats as listed below:
Abstract (line 21) - A·cm⁻²
Table 3 (page 13) - A/cm²
Conclusion (lines 453 & 471) - A-cm-2
It would be best to choose one format and use it uniformly throughout the text, tables, and abstract.
Authors are also advised to check the whole text for similar issues.
Author Response
Dear Reviewer, We would like to express our sincere gratitude for devoting your precious time and providing valuable professional insights to review our manuscript. Your positive evaluation of the revised work and affirmation of its contribution to the field of composite coatings and surface engineering have greatly encouraged us. We have carefully addressed all the minor typographical errors, grammatical inconsistencies, and unit format issues you kindly pointed out, with detailed revisions implemented as required. Please find our point-by-point responses to your comments below, and all corresponding corrections are clearly highlighted/in track changes in the re-submitted manuscript files. We appreciate your continued guidance and look forward to your further feedback. Please see the attachment.
Author Response File: Author Response.pdf
