Investigation into the Corrosion Wear Resistance of CoCrFeNiAl_x Laser-Clad Coatings Mixed with the Substrate

Round 1

Reviewer 1 Report

The manuscript studies laser clad HEA coatings (with and without Al content) On Ti6Al4V alloy. The manuscript cannot be accepted as such and needs to be improved. Following are comments on the manuscript:

1. Include a SEM image of the coating-base metal cross-section to show the interface more clearly.
2. For corrosion experiments was the solution maintained constant or recirculated to maintain the concentration? How was the stability of the system during PD curve established? Discussion on OCP to observed film stability is not given in the manuscript. Why was Nyquist plot not studied to observe stability of the passivation layer?
3. Figure 6, show a cross-section of the wear profile for substrate and with coating for one case to illustrate the change in profile depth. Also "substrate" is spelt wrong in the figure.
4. English language needs to be improved. The manuscript has been poorly compiled and is very difficult to follow and needs extensive language improvement.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

This manuscript presents a study on corrosion wear resistance of the high-entropy CoCrFeNiAlx coatings synthesized on Ti6Al4V by laser cladding. The manuscript is interesting for readers. However, some few points should be corrected before publishing:

1. A strong improvement is requested in order to provide the experimental informations related to the structural X-ray characterisation of the various phase structures indicated as being observed. Where is for example Ti2Ni phase in the coating coming from?
2. Clear chemical informations provided by SEM / EDS analyses and cartographies are also requested. Why only EDS point analyzes were performed and there is no analysis from a larger areas? Where are the main elements of the coating?
3. The microhardness was measured at cross sections in this study. How many cross sections were selected for each experiment case? How were the locations selected?
4. Why is there no image of the microstructure in the substrate-coating transition zone presented in this manuscript?

Author Response

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Reviewer 3 Report

- English language of the manuscript is acceptable in general. However, it would be much better to improve. Please avoid unnecessary long sentences. Also, some grammatical mistakes can be observed. For example dutectics.
- Avoid abbreviations in the “Abstract”. In addition, please mention your findings. This part should be written specifically not general. It is too lengthy and may be shortened.
- It is necessary to create a pure HEA coating without mixing with the substrate.
- It is necessary to study and compare the properties of pure coating without mixing, with coating mixed with a substrate.
- Interface of coating - substrate and composition changes in coating with sufficient evidence should be examined and characterized.
- Metallography of the cross-sectional structure of the sample should be given.
- The composition of the points specified in Figure 2 (a3 and b3) should be given in a separate graph.
- Title correction based on the lack of net HEA coating on the surface.
- It is necessary to study the influence of elements and changes in chemical composition in the joint interface. For this purpose, reviewing the following refs could be helpful:
Journal of Central South University, 25, 2018, 1849-1861
Scripta Materialia 210, 2022, 114473

Author Response

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Reviewer 4 Report

Dear Authors,

I have read with interesting your paper titled "Investigation into Corrosion Wear Resistance of the CoCrFeNiAlx Laser-Clad Coatings Fabricated on Ti6Al4V". It fulfills the aims and scope of the Metals journal. Presented investigations are very interesting. Results are described well. Moreover, they have been discussed and analyzed. The paper could be published in my opinion after minor revision.

My comments are listed below.

I suggest you put the phrase "HEA coating" in keywords.

Introduction: - This part is very strong. You have described relevant scientific background for presented investigations. However I have a few suggestions:
- line 33 "Ti6Al4V is a commonly used anticorrosive alloy" should be corrosion resistance alloy,
- Line 46 You have been mentioned about widespread interest and developed rapidly laser cladding with two references only, in that place I suggest to extend number of citations et least about 10.3390/ma14112745

Materials and Methods: This part is clear

Results and discussion:
- line 193 - "honeycomb-like structure is not suitable to describe microstructure of samples presented on Fig. 2. In my opinion cellular-like is more suitable for that state.

Conclusions: - I suggest to add an introductory sentences to the conclusions

Regards

 

Author Response

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Round 2

Reviewer 1 Report

The manuscript has been edited by the authors to include the changes suggested by the reviewers. The revised manuscript can be accepted for publication.  

Reviewer 3 Report

The revised manuscript is accepted.