New Die-Compaction Equations for Powders as a Result of Known Equations Correction: Part 2—Modernization of M Yu Balshin’s Equations

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Based on the theory of M. Yu. Balshin, the authors have derived two new compaction equations to describe the pressure-relative density relation during the compaction of powders. The accuracy of two equations was discussed by substituting various experimental data. The results show that the second equation is satisfying the precision and comprehensive applicability. Overall, the manuscript is well structured and understandable. It is recommended to be accepted after the following revision.

（1）page 1 line 11, ‘p’ is missing in the equation.

At present, equations derived from the nonlinear elasticity theory pay more attention to the fitting of the experimental data, ignoring the interpretation of the physical meaning of the parameters. However, the powder pressing process is complex and multifactorial. If probable, it will be further improved the accuracy of the equations by establishing the relationship between the parameters and the pressing process. Therefore, three questions are expected to be considered by the authors. Those are:

(1)     The authors obtained the constants in the equations by fitting the pressing-relative density curves of different powders. Obviously, the hardness of the various powders is different. Please consider that whether the constants in the equation are related to the hardness of the powders.

(2)     If comparing Table 2.5, Table 2.8 and Table 2.9, readers would appreciate an simple explanation on why the value of a in Table 2.8 is quite abnormal.

 

(3)     According to Table 2.8, it can be found that the value of a corresponding to the fine powders is much larger than the coarse powders, please consider whether particle diameter of the powder will affect the constants.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript "New die-compaction equations for powders as a result of known equations’ correction. Part 2." proposed two fitting pressure-density equations for powder compaction. Overall, the content would be meaningful in this field. However, some issues should be addressed before making a final decision on this manuscript.

1. The introduction part doesn't meet the academic requirement, though this manuscript is the second part of a series. The readers want to know the background, meanings, related work of this manuscript, without checking another one. The authors only cite one reference - their own under-peer-review paper, which is not acceptable for a journal paper in my opinion. So I suggest the authors carefully rewrite the introduction part and cite properly, in accordance to the main contents of this second-part manuscript.

2. Please delicately explain why the title mentions this approach is "discrete", I cannot find much information about this key concept.

3. Most of the cited references are quite old, and a few key references are in Russian, which hinders the readers to dig and track the references. Actually, there are numerous up-to-date papers on powder compaction recent years. The authors should revise and properly cite some newly published papers.

4. The authors could add some discussion about accuracy, physical meaning, application feasibility, by comparing two proposed equations with some others, for example, Heckel, double logarithmic equation.

5. Some concern about the fitting coefficients in Table 2.4, why w of FeKH2 is only 14.974, much smaller than others, though the differences in Fig 2.4 are not obvious. The same issue in Table 2.5, w=5.0 for FeKH3, very small compared to others. The authors should double check and make some discussion about the fitting coefficients in the context.

Comments on the Quality of English Language

The English language is good to go.

 Some typos: line 11 miss p; line 231 should remove of.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The author of the article focuses on the issue of modifying the Balshin equation describing the process of compaction of powder materials. The article lacks a materials and methods section, the author refers to his previous work, which cannot be found on the Internet. In the cover letter, there is a reference to Part I of this article, but it has not yet been published. For this reason, it is not clear how he arrived at the experimental data that are used in the graphs. Adequate world sources are not used in the references, the author refers purely to Eastern European literature, and omits authors such as R. Heckel, Kawakita, etc., who are groundbreaking in the field of powder compaction. The graphic editing of the article is at an acceptable level, but it does not follow the paragraphs found in the template. To recommend this article, I would ask for a major revision, especially by adding Materials and methods and adding references.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have carefully addressed the question, and thus the publication of this manuscript is recommended.

Reviewer 3 Report

Comments and Suggestions for Authors

Paper Can be published in this form.