Analysis of the Relationship between APS Thermal Spray Parameters of Ni5Al Particles and Coating Characteristics
Round 1
Reviewer 1 Report (New Reviewer)
1. The labels of rhombohedral and stellate don’t represent the velocity and temperature clearly in Fig.9.
2. What is the substrate material and its state? It is related to the adhesion strength between the Ni5Al coating and the substrate.
3. What’s the coating’s porosity after deposition? It takes great effect on the coating’s properties.
4. What’s the coating’s cross-sectional microstructure? It is essential.
5. Figure 16 shows the rupture surface after the adhesion test. The rupture surface could be magnified to characterize the fracture mechanism.
6. The conclusion was so complex. It should be refined.
Author Response
Dear Editor:
Responses to your comments have been addressed in the attached file.
Author Response File: 
Author Response.pdf
Reviewer 2 Report (New Reviewer)
1. The title of the paper is “Analysis of the relationship between APS thermal spray parameters of Ni5Al particles and coating characteristics”, but the paper lacks quantum of studies and discussion relative to the title of this work.
2. Avoid the irrelevant references. In page 1, Line no. 24: [4-18]. Provide the specific reference to the sentence.
3. Thermal spray equipment is given in Fig. 1, but where is the results of specimens coated with this XRD, SEM, and XPS etc.? Without providing results, what is the significance of the experimental setup?
4. In Table 1, the operating parameters, such as Current, Gas flow rate, Powder flow rate are given. What about the Voltage/Power, Carrier gas for powder, Substrate distance etc…
5. Proper modelling is required to explain the in-flight particle velocity and the temperature measurement.
6. The present condition is suitable only for this Ni5Al material; how could it possible to denote the same for other materials, and using other gases.
7. What is the reason for choosing H2 gas?
8. Particle temperature, velocity profile graphs can be represented together; there is no point of providing separately. The discussion portion is very weak.
9. Check the references 26 and 27, provide the correct source.
10. Without all these how to explain the relationship between the operating parameters and the parameters characterizing the particles. The entire paper is to be rewritten completely including all the necessary studies, results and proper discussion.
English should be improved.
Author Response
Dear Editor:
Responses to your comments have been addressed in the attached file.
Author Response File: Author Response.pdf
Reviewer 3 Report (New Reviewer)
It is required to incorporate the suggestions/comments in their manuscript.
1. The author must include the result part in the abstract and make it more quantitative.
2. The research gap followed by the objective of the work should be more elaborated for better understanding.
3. The heading should be Materials and Methodology. Further, the author can include the materials used in this study with their supplier name.
4. The heading should be Results and Discussion. The discussion part is missing. The author has only written down the result part. Therefore Include the discussion for each figure with proper justification and scientific way.
5. The author should provide the schematic image of the experiment and sample fabrication procedure rather than the machine image.
Author Response
Responses to your comments have been addressed in the attached file.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report (New Reviewer)
Accept
Author Response
Thanks for your valuable advice
Reviewer 2 Report (New Reviewer)
The authors have addressed the few queries satisfactorily; still, the authors have not provided the necessary studies, which was been sought in the previous review,
The confirmation study on the composition of the material used Ni5Al (XRD / XRF / EDS) is not provided.
Fig. 18 morphological features are not clear; the micron scale represented is not visible. The authors have mentioned only the porosity of the coating, no further discussion about the coating microstructure is found in the manuscript. What about the phase formation after coating? As it is the atmospheric coating, the oxide phase will be formed along with Ni and Al. Hence, give clear studies and results on the same.
“The power of the spray is set up by the current, one of the parameters studied” What about the Power in Watts (Power = Current X Voltage)?
Avoid the usage of the first-person pronoun “we can”. Reduce the usage of the word “information”.
English should be improved.
Author Response
In the attached document you can find the answers to the comments.
Author Response File: Author Response.pdf
Reviewer 3 Report (New Reviewer)
No Comments
Author Response
Thanks for your valuable advice
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
The manuscript reports the results of an investigation aimed at predicting particle velocity and temperature during APS as a function of 3 spraying parameters: arc current, H2 flow rate and powder flow rate.
The significance of the gathered results appears very limited. No additional information or interpretation was offered with respect to the very well-known mechanisms of coating build up, already widely discussed in the available literature. A simple DOE analysis (of just 3 parameters and 3 levels) of a physical phenomenon cannot be the only content of a scientific paper.
No evaluation of the properties of the deposited coatings was offered, and results are said to be “sufficiently flexible to allow its application when changing any parameter not incorporated in the analysis”, but no demonstration of the robustness of the analysis was offered.
It is the opinion of the reviewer that the present manuscript cannot be accepted for publication.
-
Reviewer 2 Report
In this manuscript the authors study the effect of different input parameters on the inflight characteristics of Ni-5Al particles that were sprayed with APS. They used a Surface One thermal spray booth and a thermal flux sensor to assess how current, H2 flow, powder flow rate affect the Ni-5Al particle temperature and velocity.
1) Introduction is poor. Authors should expand the introduction and discuss similar works in more detail.
2) What is the novelty of this work? Authors need to explain this in detail.
3) What is the reason behind the selection of the specific input parameters? Some of the selected input parameters like the powder flow rate of 60 g/min is very high and would lead to improper melting of the powder, poor adhesion and high porosity of the coating.
4) Results are very brief, authors just describe the figures with minimal analysis and without expaining the mechanisms behind every input parameter change. Results need to be expanded.
5) Figures 2-7 are not presented properly. The authors didn`t use units to the relevant axis. Flow on those figures corresponds to mass flow but this is not clear and the reader can be confused with H2 flow. The figure plotting is also poor.
Unfortunately, at its present state, this manuscript is like a technical report rather than a scientific paper. As such it is suggested to be rejected.
Some changes are required but in general the quality of the english language is good.
