A Physical Mechanism-Based Model of CoCrFeMnNi High Entropy Alloy Considering Adiabatic Heat Effect for Hot Bulk Forming Processes

Round 1

Reviewer 1 Report

The authors provide a paper dealing with the A physical mechanism-based model of CoCrFeMnNi high entropy alloy considering adiabatic heat effect for hot bulk forming processes. The paper can be of interest for Metals but MAJOR revisions are requested.

-          The authors must expand the literature work with more recent research on thin film high entropy alloys doi.org/10.1016/j.surfcoat.2021.126945 and doi.org/10.1016/j.mattod.2021.10.025. This will be very important to provide a broad overview of such materials either in bulk and in thin film form

-          Table 2 is impossible to understand. What are all those equations? What is the physical meaning ?

-          Similar to the previous point table 3 does not make too much sense. Can the authors provide a better way to present the data and describe the physical meaning ?

-          The authors must comment in a more detailed way about the local mechanical properties of the materials. As a matter of facts, there are techniques which manage to extract fracture toughness, residual stress etc. on the local scale such as in doi.org/10.1016/j.matdes.2019.107762, doi.org/10.1016/j.matdes.2016.06.003. The authors must comment on these work and provide an improved discussion of the mechanical properties at the submicrometer scale. This I think will be of capital interest for the present paper, while representing a good outlook for the future work.

-          Connected to the previous point, a nanoindentaion analysis can also be performed especially in cartography mode to extract the elastic modulus and hardness for this composite materials. This can provide really high quality results.

Author Response

Thanks a lot for your professional review on the manuscript. We have carefully considered the comments, and made necessary revisions on the manuscript. The revised contents are highlighted, and the one by one response is given in the attached word document.

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear authors,

The reviewed work A physical mechanism-based model of CoCrFeMnNi high entropy alloy considering adiabatic heat effect for hot bulk forming processes (metals-1761360) concerns an important area of science, namely design and manufacture of new materials with special properties, which are undoubtedly HEA alloys. The pursuit of the practical application of these materials by modeling their behavior in the hot-forming process is undoubtedly the right direction. And taking into account in the currently existing constitutive models the influence of the adiabatic thermal effect on the structure of the deformed material is your contribution to the development of this issue.

Overall, the article is based on a satisfactory literature review. Major flaws in the research and editorial process were avoided. The only drawback seems to be a too modest verification of the results of numerical calculations with a physical experiment (only 3 cases). This raises doubts as to the credibility of the considerations.

I recommend making the following corrections:

23 - … R-value and AARE … - the meaning of these acronyms is not defined.

63 - …FE… - the meaning of these acronyms is not defined, moreover, the literature uses the term FEM (finite elements methods), not FE.

68, 73 - … ZA model and Arrhenius-type model and Cook - no reference to the literature source describing these models is provided.

69-73 – Wang et al… - Stylistic errors - too complicated sentence structure causes problems with its understanding. Write shorter sentences. Similarly in paragraph 225-234, 315-327. This remark applies to the entire article, hence the recommendation to make a professional linguistic proofreading.

101 - …grain size is approximately 23.9103 μm… - the posted result has not been properly developed in terms of its notation.

Fig. 1 – No photo showing the microstructure of the material (SE or BSE). Fig. 1a and also Fig. 5 - the scale of the photos is misleading as the presented area is too small to correctly determine the grain size. Hence the question: what was the size of the area on the basis of which this parameter was determined, how many grains were counted and what exactly were its results (e.g. standard deviation ...). Write it down in the body of the article.

113 - … Gleeble 3800 thermal-mechanical simulator - Please, provide the name of the laboratory or institution where the tests were performed. In what kind of atmosphere were these tests performed?

114 … robust temperature - What does it mean?

124 - … between 950°C and 124 1050°C, and the strain rate range was 0.001/s~0.1/s - Not ranges, but specific values. There is no value for the cooling rate.

134 - …using the Euler method… - literature?

144 - However, high strain-rate deformation is often adiabatic… - This process may be accompanied by instabilities of the deformation process (e.g., adiabatic shear), which may cause significant differences between the experiment and its numerical model.

152 - … 8.042g/cm3, and the specific heat is 0.43J/g K - Check if the units used are compliant with the SI system.

Table 2 - Literature sources for each of the equations listed should be provided in the table.

207 - Please check the correct numbering of tables, figures, and their references in the text throughout the article (visible errors). Also 303 line.

251 - … R-values of 0.8926 (0.001/s), 0.8537 (0.01/s), 0.85405 (0.1/s)… AARE is 0.0103, 0.0224, 0.0254 - Please consider writing these values. These results were not analysed and elaborated. Especially in the conclusions they have already been given with accuracy to one and two significant places. Also in line 297.

Fig. 2 - Please standardize the drawings in terms of scale on the axes. In the caption to the drawing, state the test temperature.

269 - The comparison results are divided into a Figure 3(a) and Figure 3(b) and - It is superfluous to repeat - delete. Similarly in verse 333.

Fig. 3 - The value of the stress scale should be the same for both drawings. Please make the legend independent (symbol, line - meaning) and not as reference lines. Figure a and b have been mistaken in the caption.

354 - … for the strain rate 0.1/s in which the grain size remains almost constant - Why? Maybe it is wrong?

359 - … the fast deformation is not to enough form recrystallization … - This explanation is not satisfactory enough.

Fig. 6 - Please move the error bars so that they do not overlap. Why is the deformation for 0.001 / s different from for the other cases ?! In the description of the experiment there is only a note that it was 0.5. This is a serious incompatibility.

376, 378, 387 - …successfully…, excellent… - These are euphemisms, and the results obtained do not justify their use.

Author Response

Thanks a lot for your professional review on the manuscript. We have carefully considered the comments, and made necessary revisions on the manuscript. The revised contents are highlighted, and the one by one response is given in the attached word document.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

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