Microstructure and Tribological Properties of HVOF-Sprayed Nanostructured WC-12Co/Fe3O4 Coatings
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis paper effectively demonstrates the potential of using nanostructured WC-12Co and Fe3O4 powders in composite coatings and demonstrates an innovative approach to improve tribological properties through HVOF spraying. The manuscript is generally well-structured with a clear division of sections. However, responding the following comments are important to make suitable the study for publication.
(1) -In Tables, there are commas in decimal numbers.
-There are errors in the numbering of the figures. For example, there is Figure 16 after Figure 14.
-The graphics and images in some figures are blurred and the image quality is poor. In addition, the numbers in the text and measurement bars are very small and very difficult to read.
For example, Figures 2,3,8,9,9,10,10,11,12,12,13,14,14,16,14
(2) The manuscript states, "the most significant impact on the friction coefficient is the Fe3O4 content in the sprayed mixture," but it does not provide a clear mechanistic explanation for why Fe3O4 impacts the friction coefficient significantly. It would be beneficial to elaborate on how Fe3O4 affects the tribological properties of the coating.
(3) The text mentions the formation of W2C due to decarburization of WC under high temperatures during spraying. However, the implications of this phase change on the properties of the coating (like hardness and wear resistance) are not discussed. A discussion on whether the presence of W2C is detrimental or beneficial would provide a more complete understanding of the material's performance. In addition, it is a known fact that this phase is a hard phase, but it is important to compare the results of the present study with similar studies in the literature.
(4) The manuscript concludes that "Other input parameters do not have such an influence," based on ANOVA results showing F-values below 1 and p-values greater than 0.05. It would be clearer to state that these other parameters were found not to have a statistically significant impact on the measured properties, which implies that their effects are either negligible or need further investigation under different experimental conditions.
(5) The way in which results are reported in the statistical sections can be modified as in the following example. For instance, the manuscript could benefit from a consistent format when discussing the results of the ANOVA, including always specifying the corresponding F-values, p-values, and what they imply about the data.
(6) In the study, it should be stated which other process was applied after the sanding process of the coated samples. The reason for this is as follows. When SEM images are examined, no sanding traces are seen. Therefore, it is an indication that an additional process was applied.
(7) Literature support in the "results and discussion" section was found insufficient. Comparisons and discussions with similar studies in the literature should be increased.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsIn this paper, composite coatings containing solid lubricants were prepared by HVOF spraying technique, however, the friction properties were only studied by obtaining the friction coefficients to be statistically analyzed without analyzing the friction and wear mechanisms. I think the manuscript is more like a project report than an academic paper and I do not recommend it for publication.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe paper is written about the Microstructure and Tribological Properties of HVOF Sprayed Nanostructured WC-12Co/Fe3O4 Coatings, it is a well-written paper, but there some major concerns about it, for example, there isn’t enough explanation about the reason for considering linear behavior in modeling or the main reason for ANOVA using, or it needs more explanation about experiments, you can find more details about the paper in the below:
1. In the introduction, it is better to provide a more detailed explanation of the paper's innovation. Additionally, a brief description of the paper's structure should be included.
2. A binomial distribution was used for conducting the research. Can you explain the reason for selecting this distribution? Are there any references to support this selection? And another question about modeling, Why ANOVA?
3. In the paper line 128, it is written that: “In HVOF spraying processes, it is assumed that the coating property (output parameter) is related to the input factors of the spraying process by a mathematical relationship (1)” Why? I think is better to add more detail here or add a reference.
4. In line 132, “It seems that the following linear function meets our expectations (2): 132 y = a0 + a1x1 + … + anxn”, What are your expectations? It is unclear, Why the authors just considered a simple linear behavior. If it is a simplification, it should address some hypotheses with reference to previous papers or scientific facts.
5. In line 135, what was the normalization method?
6. Please add more detail about imaging (equipment, etc.) for Figure 1 and other similar figures.
7. Legend for Figure 2 is needed (for example line with circle represents….)
8. I think maybe using a bar chart is a better explanation for grain size.
9. The numbers in fig9, are Unclear.
10. The quality of Figure 10 is low and needs more explanation (Also Fig.13).
11. About experiments, how many times do authors repeat the tests? Is better to add more detail about experiments.
12. More explanations are needed for Fig.10, Fig.14, and Fig.17.
13. There are some minor problems too:
- The font of the tables does not match the text
- Plots in the figures need a legend
- If is possible, is better to make an appendix and send some figures there, there are 17 figures in the paper, or if is not impossible, maybe merging is a better solution.
Comments on the Quality of English LanguageMinor editing of English language required
Author Response
Please, see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
Comments and Suggestions for AuthorsDear Authors, thank you so much for providing information and answering.
All issues are solved.
