Influence of Spray Angle on Particle Deposition and Thermal Shock Lifetime of Embedded Micro-Agglomerated Particle Coatings
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe Reviewer would like to thank the Authors for their submission. The proposed manuscript is very interesting as it explores the influence of spray angle on particle deposition and the thermal shock lifetime of embedded micro-agglomerated particle (EMAP) coatings. This topic seems to be a continuation of prior work published elsewhere by the Authors and therefore, the new findings build strongly on prior knowledge and concepts. It clearly provides valuable and interesting information that furthers the initial work and the scientific quality of the work is overall, very good. Nevertheless, there are numerous sections of the work that provide numerous questions and doubts as to how some conclusions are drawn, notably in the first sections of the manuscript, and these need to be addressed. Some questions and comments are made and follow, as well as suggestions to improve the overall impact of the paper through improved contextualization of the current study.
Please see attached PDF file for further detail.
Comments for author File: 
Comments.pdf
A lot of grammatical mistakes, misattributed adverbs and imprecise vocabulary appear throughout the manuscript. In some areas, this is not a major issue, but when discussing hypotheses, choices of powders/phases or experimental procedures, topics quickly become confusing to follow and the manuscript loses a lot of quality as a result.
For improved quality, I would strongly suggest having it reviewed by others who may assist on this aspect. Some of these points may be brought up in this review, but the list will not be exhaustive.
Please see attached PDF file for further detail.
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe manuscript provides a fresh look at one of the key parameters used in coating research. The methodology is well designed, and the results are presented in a manner that is easy to understand. However, the authors must address the following key points in order for the manuscript to be suitable for publication.
Line 45, 54-57: provide reference sources for these claims.
Always leave a space between the number and % sign, wherever used.
Provide all the available properties regarding the powder used in both phases, preferably in a table.
Line 151: instead of relying on such a relationship, use a relationship curve, which would provide a higher accuracy.
Figures 4, 6, 8, 10, 14, and 15: the resolution of all the images is too low to assess the porosity. Provide higher-resolution images.
Authors should address the variation of the hardness with the porosity as there are conflicting results when the angle is 50°.
Provide SEM images of the cross-section of the specimens used. Need to evaluate the bonding of the layers to justify the thermal shock-resistant results by eliminating poor bonding to the substrate.
Comments on the Quality of English LanguageThere are minor editorial errors, which can be eliminated by proofreading the manuscript again.
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe authors have investigated the influence of spray angle on particle deposition and thermal shock lifetime of embedded micro-agglomerated particle (EMAP) coatings. The investigation is suitable for publication in Coatings but some minor corrections should be made.
Lines 9-12: It’s better to move the first two sentences of Abstract to the Introduction.
What is the error of porosity measurements? All porosity values are very close and additional data should be included on the porosity measurement metrology. The best way is to confirm the measured values by additional methods, for example, nitrogen adsorption method.
The confidence intervals are very large in most figures. What is the reliability of conclusions about observed trends based on these figures?
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsI would like to thank the Authors for their extensive revision as the quality of their submission has increased. Nevertheless, I believe there are certain sections where improvements may still be made.
0. Surprisingly, the "Response to the Reviewer" includes a Review that does not reflect this Reviewer's initial assessment. Notably, "Extensive editing of English language" was required, and the "Response to the Reviewer" indicates that "No issues were detected". Over 60 comments were made in the first review to assist with this point (as English may not be an easy language), but it was clearly indicated that they weren't complete and the latest additions have introduced further vocabulary and grammatical errors. More specifically, the English in this paper must again be revised by the Authors.
1. Line 29: please clarify the value of all 4 references that are listed. What value do all 4 hold to be cited here?.
Answer: Thank you for your suggestion. These four articles have relevant introductions to thermal barrier coatings, which played an important role in my initial learning of the basic knowledge of thermal spraying, so they has been cited
Response : It is still unclear what these 4 references bring to the discussion : it should be clear in the text why these 4 references are useful to your Introduction, notably because 3 of the references are from the same author (Padture et al.) and therefore they seem quite redundant. In other words, only 1 of the references would actually be useful unless explained otherwise.
2. Line 37 : the modification "plasma flame" is incorrect as a "plasma", by definition, is not a flame. Please remove "flame".
3. Line 37 : As already mentioned in the initial review, the use of all accronyms should be revised. Once TBC has been established as an accronym in text (line 29), all occurences of "thermal barrier coating" should be abbreviated to "TBC" (there are currently 4 in the text that require revising)
4. Line 54-55 : While HVOF does correspond to a supersonic flame spraying technique, the actual accronym should be explicited. Also, as APS has been described in Line 36, "atmospheric plasma spray" should be revised and replaced throughout the rest of the text (3 remaining occurences).
5. Line 56 : There is an occurence of "HOVF" that is still remaining.
6. Line 63-64 : This phrase currently has no meaning. "the coating **exhibits**" maybe ? Please revise.
7. Line 60 : it is unclear how the variation in spray angle contributes to reducing roughness, as low angle erosion mechanisms from solid particles would lead to a higher degree of plowing or abrasive wear. Furthermore, the roughness values provided by [14] overlap and the trend that is ascertained does not seem valid, nor is the scale of differences even really noticeable. Please clarify and revise.
Answer: Thank you for your suggestion. The trend of decreasing roughness is indeed unclear in [15], but in [17], there is a more significant decrease in roughness. Relevant changes can be seen in the revised draft
Response : If the Authors agree that the reference in question (now reference [16]) does not show a decrease in roughness, it must be removed from this part as it does not defend the point they are looking to make.
8. Line 59-64: How are the wear properties of HVOF coatings and decomposition behavior of WCrelevant in this situation? While the variation in properties related to varying the spraying angle has value, the detail that is given does not appear to be relevant. Please revise and clarify.
Answer: Thank you for your suggestion. Relevant changes can be seen in the revised draft. Line 66-69: ...Additionally, the smaller spray angle prolongs the period of reaction between the WC-Ni powders and oxygen mainly from ambient air entrained in the slow-down region adjacent to the deposited surface, and thus promotes the decomposition of the WC phase [17].
Response: This point does still not appear relevant to your work (which does not discuss WC-Ni, nor the decomposition of phases related to spraying) and a suggestion would be to remove it.
9. Line 100 : the phrasing "changes in the internal special pores of the coatings" is very unclear. Please clarify in the text what is meant by this.
10. Line 119-120: What is the origin/manufacturer or manufacturing process for the described powders ?
Answer: Thank you for your suggestion. Two powders are all from Anhui Yingrui Youcai Technology Co., Ltd., Anhui, China
Response: This should appear in the text. Please include it.
11. Line 147: Which polishing procedure ?
Answer: Thank you for your suggestion. Adopting mirror polishing
Response: Please clarify this in the text.
12. Line 169-170: Please discuss the validity of such a formula to determine the elastic modulus of the coating. A reference or two to support this would be ideal.
Answer: Thank you for your suggestion. This formula has been applied in previous work [21].
Response: Prior work that simply uses a formula without discussing it is not a valid reference. Please refer to the actual source reference (that [21] uses) and that is Marshall et al, "A simple method for determining elastic‐modulus–to‐hardness ratios using Knoop indentation measurements" (1982)
13. Line 190-191 : do you not mean "images" instead of "planes" ?
Comments on the Quality of English LanguageSurprisingly, the "Response to the Reviewer" includes a Review that does not reflect this Reviewer's initial assessment. Notably, "Extensive editing of English language" was required, and the "Response to the Reviewer" indicates that "No issues were detected". Over 60 comments were made in the first review to assist with this point (as English may not be an easy language), but it was clearly indicated that they weren't complete and the latest additions have introduced further vocabulary and grammatical errors.
More specifically, the English in this paper must again be revised by the Authors.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsNecessary changes have been carried out and the manuscript can be accepted in the present form.
Author Response
谢谢你的建议。
