Effect of Recovery Treatment on the Microstructure and Tribological Properties of Ultrasonic Impacted Al₂FeCoNiCrW_0.5 High-Entropy Alloy Coatings

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1. I believe the keywords are of too general character. Recovery treatment or wear resistance could be keywords in any research of this type. The substrate is the main item of the research. Isn’t it? It seems to me, the coating material merits to be mentioned in the list.

 

2. The respected authors are encouraged to underline more clearly the novelty of their research the readers to see the relevance of the improvement proposed and by what reason this coating composition was chosen.

 

3. And what about the all-over coating thickness? All mechanical characteristics, including corrosion resistance, depend on this parameter in large extent.

 

4. It should also be interesting to know the effectiveness of adhesion of the coating to the substrate.

 

5. What is exactly the mechanism of mitigation of defects by the high-temperature UIT (lines 50-70)? These factors affect synergistically in all cases, do they?

 

6. Many metals are known to form local intermetallic compounds, carbides and silicides exhibiting different microhardness and other properties. Did the respected authors control or neglect the possibility of this effect, especially by UIT?

 

7. It seems to me, the explanation of the relationship between grain refinement and UI are perhaps reasonable but too simple.

Author Response

请参阅附件。

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The paper presents some objections that I transfer to the editor. Those must be corrected/improved from the scientific-technical point of view.

The paper presents defects/gaps that must be corrected or improved from the scientific-technical point of view. These objections are specified in the following: 

1. The steel of the substrate must be referenced according to the international standard AISI, ASTM, UNS. It is a very simple carbon steel and therefore 45# is not correct.

 

2. The operational conditions or parameters chosen both in Laser technology, UIT must be specified as to why these and not others, as well as the temperature of the recovery heat treatment after UIT. Why this or  not others that could also be used.

 

3. Within the elements chosen for the manufacture of the high entropy alloy, why W was included?

 

4. Can you clarify those sentences in function of the results:

 

“No carbon is present in the top microstructure, indicating that the carbon from the substrate did not migrate into the top of the melt pool during cladding.”

 

and :

 

 "As shown, ultra- 192 sonic impact treatment increases the dislocation density in the cladding layer, gradually refining grains and forming a nanocrystalline layer".

 Please, which is the evidence?.

 

5. The work indicates that there is a process of reduction of dislocations, presence of new phases, precipitates, depending on the UIT process or the subsequent heat treatment. The images presented in SEM are not really of very high quality and of course it would be satisfactory to include TEM/STEM images that really confirm their working hypothesis.

 

6. No international standard is followed in wear resistance tests, for example ASTM, so their results can only be compared with each other but not with other works by other authors. Please, it is essential that we follow joint standards in research work in order to compare the quality of the final result.

 

7. The authors make a final discussion, but a conclusions section would be appreciated.

Author Response

Please check the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The paper now has been improved a lot, nevertheless :

- The use of TEM/STEM and also HRSEM technologies will be necessary, in future papers, based on this topic.

- Please, always use, international standards in all your testing.

- Finally use, in the text, the following reference UNS (Unified Numbering System) in the used carbon steel, G10450 instead of 45.

REGARDS 

Author Response

请参阅附件。

Author Response File: Author Response.pdf