Microplasma-Sprayed V2O5/C Double-Layer Coating for the Parts of Mini-Hydropower Systems
Round 1
Reviewer 1 Report
The scope of the individual chapters is not well balanced. The introduction is very intensive, while important information is missing in the experimental part and the results. The experiments are insufficiently described. The evaluation of the measurement results is incomplete or incorrect. The calculated data of the corrosion experiments are in contrast to the measured values of lg(i). A chapter 4 does not exist.
All results must be checked carefully. There is largely no interpretation and discussion of the results.
The following examples are representative of some of the shortcomings of the manuscript.
- Materials and Methods
In the experimental part, complete information on all methods, measuring devices used and the respective manufacturers must be given (e.g. CoatMaster – which instrument? MPN-004 plasmatron – manufacturer? JEOL JSM-6390LV – transmission microscope?).
In addition, the information on the experimental conditions must be completed (e.g. graphite coating – gases, temperature? hardness – Vickers, Knoop, Brinell? wear resistance – material of the ball? corrosion test – potentiostatic or potentiodynamic, oxygen-free electrolyte: yes or no, solution buffered: yes or no. What do you mean by potential feed rate and what by average sweep speed? How do the following values fit together potential feed rate 50 mV/s and average sweep speed 603.94 mV/s?
- Results
Figure 4: The scale is difficult to see. What is the meaning of the text field “spectrum” in the REM picture? No spectra are shown throughout the article.
Figure 5: What do the four pictures show? Usually the distribution of elements is examined during the mapping.
Figure 6: How was the sample prepared for the TEM investigation? Furthermore, a scale should be given in the pictures.
Figure 7: Are these the results of multiple measurements? How big is the standard deviation?
Table 1: What is the relationship between the measured and calculated values? What is the relationship between wear rate and wear resistance?
Figure 8: What relationship is shown in the graph? The axis labeling is missing.
Table 3: The calculated values cannot be correct. Was the mass loss measured or calculated?
Author Response
Please see the attachement
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Dear Authors,
The topic is interesting and probably of interest of thermal spray community. However, if you consider the publication in the journal with such high quality and IF, the manuscript needs serious correction. All my comments are mentioned in the attached .pdf file. I would suggest to work on the quality of all figures given in the paper as well.
Best regards
Comments for author File: Comments.pdf
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
There are some spelling errors (see attached file).
When comparing the two versions, it is noticeable that a number of significant values / measurement parameters have been changed drastically without any comments for the reviewers, e.g.:
thickness of the V2O5-layer: 4.5 µm (version 1, row 142), 84.5 µm (version 2, row 138)
thickness of the C-layer: 6 µm (version 1, row 157), 115.4 µm (version 2, row 160)
potential sweep rate: 50 mV·s-1 (version 1, row 171), 0.2 mV·s-1 (version 2, row 192)
The calculated values given in Table 3 are still incorrect. The individual values are contradictory and must be corrected. This is valid for all three samples. An example is given below.
If lg(i)=-2.36 then i=4.365·10-3 and not 6.31·10-4 as indicated in the table.
The values for j can neither be calculated from lg(i) nor i.
j=i/S=6.31⋅10-4A/0.601cm2=1.05⋅10-3A/cm2 ≠3.08⋅10-4A/cm-2.
Which material do the masses refer to? There is no proportional relationship between icorr and m.
When the values of m and l relate to a period of one year, what is the relationship between l and R?
Table 3 needs to be thoroughly revised before the paper can be published.
Comments for author File: Comments.pdf
Author Response
Many thanks for the valuable comments. Please see the response in the attached file.
Author Response File: Author Response.pdf
Reviewer 2 Report
Dear Authors,
Some comments are given within the text. The most important for me is to address the following:
- microhardness and wear resistance - the results are given in some old-fashioned way (like hardness in MPa. Why not in acc. to Vickers scale?). It would be a way easier if you would use units similar as in other, ongoing publications. You will find some other comments in .pdf
- adhesion - there is confusion here. Different values are given in abstract and then later, within the results section. There is no evidence of the testing (figures, description of fracture, no. of samples) and comparison to literature data
- you forgot to discuss you work in the context of literature. Please, add some comparison on wear resistance, adhesion, microhardness etc.
- some figures are still in a very low quality
The article should be really carefully checked before another re-submission.
Comments for author File: Comments.pdf
Author Response
Thank you for the comments. Response is in the attached file.
Author Response File: Author Response.pdf
Round 3
Reviewer 1 Report
The quality of the item has been improved through a number of corrections.
Line 181: 4.5*4.5 mm should be replaced by 4.5*4.5 mm2.
Line 311: Please indicate the substrate and the coating in the Figure 9 (Line 299: The total thickness of the coatings is ~ 200 μm (84.5 μm V2O5/115.4 μm C).
Line 328: The icorr and jcorr values ​​given in the Table 3 are now correct. However, the approximately 20-fold corrosion current of sample 15CrMoV5-9 + V2O5/C should also be reflected in the mass and the corrosion rate.
If the masses have been calculated for different times (you write “mass lost in the process of corrosion”), it is advisable to state these values.
Reviewer 2 Report
Dear Authors,
Thank you for your revisions.
Please, double check your manuscript before the submission for the next time.
