Deformation Behavior and Microstructure Evolution of CoCrNi Medium-Entropy Alloy Shaped Charge Liners

Round 1

Reviewer 1 Report

Dear Editor: I would like to express my deep thanks for inviting me to review the manuscript.

Manuscript Number: metals-1708486

Full Title: Deformation behavior and microstructure evolution of CoCrNi medium-entropy alloy shaped charge liners.

The manuscript has good scientific result on the microstructure evolution and dynamic deformation behavior of a CoCrNi medium entropy alloy under an ultrahigh explosive loading rate. After taking into account the authors' corrections, I believe that the work can be recommended for publication in the metals. I have these comments:

1) The authors pay attention to the abstract. Please rewrite it according to your results.

2) The introduction part is too synthetic. I agree that there are the references but some brief explain of the high entropy alloys and the preparation method presented is necessary.

3) The authors pay attention to the addition of more elements usually produces intermetallic compounds with weak mechanical properties. I recommend paying attention to the Heusler alloys as conventional compounds, here I recommend the following papers: DOI: 10.1007/s00170-019-03534-3- DOI 10.1007/s10973-015-4716-8.  DOI: 10.1007/s10948-015-3100-z.

4) The authors should read the manuscript and clarify the command clearly. The authors have to care about typos. There are careless mistakes in some places.

5) The authors should write a short sentence about the correlation of physical properties of the produced samples.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

This is a correct experimental work on microstructural changes in CoCrNi medium high entropy alloy shape charge liner and brings incremental contribution to the material characterization of such processes before and after detonation deformation. The novelty is the application of a (medium) high entropy alloy. The introduction gives a good survey of the relevant literature. The presentation of the experiments and the description of the results, obtained by sophisticated, up-to-date techniques, is also good. The discussion and the conclusion chapters well reflects the main features and provide similar behaviour observed in other SCLs made from different metals/alloys.

Comments:

• In Fig. 3c there is also an indication that same elements have diffused into the Fe target, but later this is not discussed.
• in row 161 it is mentioned that “the width of the deformation zone reflects…”. What is this width in this investigation? (The distinction between the two, a1 and a2, zones in Fig.5 is clear, but both are the result of deformation and thus a bit confusing to call only the region a2 as deformation zone, if the authors meant this.)
• part about the segregation/desegregation is interesting. My comment to the interpretation: in the diffusion literature “short-circuit diffusion” or “diffusion short-cuts” is used to express the increased diffusivity along grain boundaries or dislocations. But as, I understood, in this case e.g. the Cr segregation is a consequence of the reduced bulk diffusion path (from the interior to the grain boundary) just because of the reduced grain size. Thus I propose to reformulate e.g. the corresponding sentence in the conclusions to make the above point more clear that it is bulk diffusion but on a nm-scale….

I propose to accept the paper after minor corrections.

Author Response

Please see the attachment

Author Response File: Author Response.pdf