Determination of Critical Velocity of Cold-Sprayed NiCoCrAlY Coating via Arbitary Lagrangian-Eulerian (ALE) Method of Finite Element Simulation

Round 1

Reviewer 1 Report (New Reviewer)

The authors presented an article about “Determination of critical velocity of cold sprayed NiCoCrAlY Coating via Arbitary Lagrangian-Eulerian (ALE) method of finite element simulation.”

In this study, the authors conducted numerical studies. I would only like to state that simulation models are not scientifically valuable because they have not been verified. Simulation studies become more useful when such studies are confirmed experimentally. My advice to authors would be to validate such studies experimentally.

The introduction and material-method sections are explained very well. I think the paper is well organized and appropriate for the “Coatings” journal, but the paper will be ready for publication after minor revision.

·       The abstract looks good. Please include all significant numerical results.

·       What is the problem? Why was the manuscript written? Please explain the reason in the introduction part. In the last paragraph of the introduction, the novelty of the study and the differences from the past in detail should be expressed.

·       Has a mesh independence test been performed? If so, please share the results with readers.

·       Please improve the image quality of Figure 3. Texts should be more readable.

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·       Please improve the image quality of Figure 10. Texts should be more readable.

·       Please correct reference 14.

·       Please fix the typographical and eventual language problems in the paper.

·       The paper is well-organized, yet there is a reference problem. First, your reference list contains no paper from the “Coatings” journal. If your work is convenient for this journal’s context, then there are many references from this journal. Secondly, cited sources should be primary ones. Namely, the indexed area shows the power of a paper and directly your paper’s reliability. Please make regulations in this direction.

*** Authors must consider them properly before submitting the revised manuscript. A point-by-point reply is required when the revised files are submitted.

Comments for author File: Comments.pdf

Please fix the typographical and eventual language problems in the paper. (Extensive)

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report (New Reviewer)

Comments on the paper are given as follows:

1-      Abstract must be enriched via valuable results, which pave the way for understanding the audiences.

2-      The Abstract should be decreased; it is too long.

3-     The authors should the results of this work need to be compared with already existing work.

4-      Some references are missing such as ASTM C633-13 standard and, standard metallographic procedures….

5-      What are the advantages and disadvantages of the current subject compared to other subjects? Authors are invited to comment this situation.

Minor editing of English language required

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report (New Reviewer)

The authors have made improvements to the manuscript following the revision. However, there are additional points that should be further addressed and considered in the manuscript:

(1) Specify the explicit dynamics method used in the finite element numerical simulation to model particle deposition in the cold spray process.

(2) Provide details on the methods employed to validate the accuracy of simulation results, especially in replicating deposition behavior across varying impact velocities and particle sizes.

(3) Elaborate on the importance of altering impact velocities and particle sizes in the simulation study. Discuss how variations in these factors impact temperature, equivalent plastic strain, and deformation characteristics of both particles and substrate.

(4) Explain how the insights gained regarding critical velocity can be practically utilized to improve deposition efficiency in experimental processes.

(5) Describe the alignment between experimental results and simulation predictions. Highlight any notable differences observed between the two.

(6) Identify potential parameters or variables that could be explored in future research to advance the understanding and control of the cold spray deposition process.

Ensure consistent use of verb tenses throughout the paper for clarity and precision in conveying the timeline of events and findings.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 4 Report (New Reviewer)

The current study deals with determining the critical velocity of a cold sprayed NiCoCrAlY coating with FEM which is an interesting topic. Overall, the introduction describes adequately the method and provides the state of the art in cold spraying technology as well as the simulation methodology that has been followed. The results were sufficiently described and conclusions , in general, were supported by results and discussion. Certain drawbacks have been reported in text mainly with text editing have been detected that need to be addressed prior to publication (authors will find more details further below). In addition, in results it has been stated that when the particle is larger its kinetic energy increases even though the velocity decreases which is contradictory and the authors need to elaborate why the kinetic energy increases in larger particles. Moreover, another point that needs to be addressed is why larger particles are deposited in substrate more easily since larger particles need more time to impact the substrate. For these reasons the recommendation is accept after minor revision. 

Line 43: Correct: "cold spray technology ... deposition temperature". This sentence has not written correctly. In addition, Cold spray must begin with capital C.

Line 88: "Rahmati et al." Reference is missing

Line 99: "Assadi et al." Reference is missing

Please whenever you mention Author et al. add also the number of reference.

Line 119: "many studies..." please add references.

Line 157-158: please mention he studies that have used explicit in cold spraying simulation.

Line 329: How is it possible to have high kinetic energy when the velocity decreases? What is the equation of kinetic energy this relationship?

Line 429: Correct: Results and discussion 

Line 473: Prior to "The results showed .." please add dot.

Line 490: Why is it easier to deposit a larger particle on the substrate.

Minor editing of English and text is required. Be careful with the syntax is some cases and spaces in text and capital letters after .dot in sentences.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report (New Reviewer)

The authors have corrected everything. The manuscript is ready for publication.

English can be double-checked for clarity.

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

This article titled "Determination of critical velocity of cold sprayed NiCoCrAlY Coating via Arbitrary Lagrangian-Eulerian (ALE) method of finite element simulation" presents a detailed investigation into the deposition behavior of NiCoCrAlY powder particles on a nickel-based superalloy substrate through finite element simulations. While the study provides valuable insights into the cold spray process, there are several issues which need to be improved:

Materials and Methods:

The section begins with vague general statements about the importance of detailed materials and methods. Instead, it should directly introduce the materials and methods used in the study.

The description of the software (Abaqus/Explicit) used for the simulations lacks detail. The reader would benefit from knowing more about this tool and why it was chosen.

The paragraph regarding meshing is quite technical. While meshing is a crucial aspect of FEM, it could be simplified for a broader readership. The selection of the C3D8RT element is mentioned without explaining what it is and why it was chosen.

Results and Discussion:

The results and discussion section lacks clear structure. There should be clear subheadings and an organized progression of information. There is an inconsistency in numbering the sections (3 and 3.2).

The conclusion that the "critical velocity" is approximately 600 m/s lacks strong empirical or theoretical support. It is unclear how this specific value was determined.

Experimental Materials and Methods:

This section is introduced abruptly without a transition from the previous discussion (additionally, there is no information about it in the title and abstract).

The description of the experimental setup is lacking detail. It should include information about the equipment used, the test conditions, and the procedure.

Conclusions:

The conclusions section should summarize the main findings of the study and their implications. However, it lacks a concise summary of the key results and their significance.

The statement about "critical velocity" is made without strong support from the simulations or experiments. This should be clarified and substantiated.

Overall Structure and Clarity:

The article's structure and organization need improvement. Subheadings should be clear, and the content should flow logically.

The terminology used in the study, particularly acronyms and technical terms, should be defined for readers who may not be experts in the field.

In summary, this article provides valuable insights into cold spray deposition, but it requires significant revisions to enhance clarity and organization. Additionally, the conclusions should be supported by stronger evidence.

Reviewer 2 Report

1. Experimental materials and methods section is not discussed properly. 

2. Results presented through simulation should have validated using appropriate experiments, however authors fails to provide detailed experiments and their correlation/validation based on selected parameters.

3. Figure 12: why the change in XRD peaks?

4. How the compressive or tensile stresses affects the peak shift?

5. Whether the authors used extensometer to calculate the error?

6. What was the value of True vs Engineering stress?

7. Overall, the presented results are weak and no in-depth discussion presented to justify the results. 

Reviewer 3 Report

1. The manuscript has written below the standard of the journal. The experimental part (section 4) is very vaguely written, with no separate result and discussion part. 

  2. It is highly recommended to measure grain size of the NiAl and Ni matrix from XRD pattern. 

3. Why the film formed has so much of roughness, not smooth? What is the thickness of the film deposited? 

4. Fig. 15: How to compare this results with the uniaxial tensile strength of the same material? Is there any similarity with the tensile strength value?

5. The results shown in Fig. 15 is true stress or engineering stress/strain ? Explain.

Writing skill is very poor.