Numerical Analysis of Serrated Chip Formation Mechanism with Johnson-Cook Parameters in Micro-Cutting of Ti6Al4V

Round 1

Reviewer 1 Report

The article can be proposed for publication after minor revision. The following recommendations should be considered when revising:

1. The keywords should be renamed, since the keywords denote the main terms used in the article, and not proper names or designations of materials (see line 22)
2. The radius of the cutting wedge must be specified, even if it is constant (see line 151 - 152)
3. The three stages of the cutting process should be named and explained (see line 186). What is the purpose of paying attention to these three stages?
4. Point „c” is not shown in Fig. 2
5. What is indicated with S₁₂. This must be checked before using this designation.

Author Response

Dear Reviewer 1

Thanks very much for your recognition of our recent research work. On behalf of all co-authors, we greatly appreciate your precious time and efforts that you have spent reviewing and commenting on our manuscript (ISSN 2075-4701). Your professional comments on our manuscript are of great value and significance for refining our paper. All changes made to the revised manuscript are marked using a yellow background. Point-to-point responses to the reviewers’ comments are in the uploaded attachment. 

Best regards
Zhongpeng Zheng

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear Authors,

 

I would like to congratulate you for your work presented in manuscript titled "Numerical analysis of serrated chip formation mechanism with Johnson-Cook parameters in micro-cutting of Ti6Al4V". I've found the idea behind the manuscript well thought and expressed and useful for readers. The followings are my questions and suggestions to improve the manuscript:

1. The JC equation used in the study should be presented before Table 1. Maybe before Line 69. Please re-arrange the section 2.2 to be read before Table 1.
2. In section 3.1, explain clearly which physical/temperature related parameters was used to perform FE studies.
3. What is the step time/strain/increment used in each figures shown in Fig. 3 and 4? When does the material exhibit each of the shown phenomena (chip initiation, strain localization, softening and serrated chip formation)?
4. Use a single uniform legend for Fig. 6 and 15 to save space and better visualization.
5. For all the discussions about the effect JC constitutive and damage model, given values (original) and actual numerical range (i.e. for -10%, -30%) should be given. For example, at beginning of section 3.2. the range of A, B, n, C, and m should be given as well as the percentage change of them.
6. Fig. 7, vertical axes should match with the units in text.
7. The manuscript has too many figures, some are very small to read especially in printed version. Please reduce the number of figures and focus only on the most important ones that backs up the main discussion presented.
8. Each conclusion started with an introductory sentence which is not needed. Please revise and shorten the section.

 

Please check the the manuscript throughly again to ensure it meets journal's requirements. There are a few editorial corrections and typos both in the text and figures. The following are some of the ones I found:

• Line 35: revise the sentence for better read.
• Line 39: what does "it" refers to. To FE or Serrated formation, please
• revise.
• Line 42: F.E.M. abbreviation was not explained before, please revise.
• Line 64: revise for better grammar: "to identify" instead of "for identifying".
• Line 243: revise the typo "increase es"
• Line 246: revise for better flow.
• Line 325: revise the typo.
• Line 396: typo n one of the figures, both marked as "Without thermal factors".

 

Sincerely

 

 

Author Response

Dear Reviewer 2

Thanks very much for your recognition of our recent research work. On behalf of all co-authors, we greatly appreciate your precious time and efforts that you have spent reviewing and commenting on our manuscript (ISSN 2075-4701). Your professional comments on our manuscript are of great value and significance for refining our paper. All changes made to the revised manuscript are marked using a yellow background. Point-to-point responses to the reviewers’ comments are in the uploaded attachment. 

Best regards
Zhongpeng Zheng

Author Response File: Author Response.pdf

Reviewer 3 Report

The paper discussed the effect of simulation parameters on the mechanism of chip formation in micro-machining of Ti alloy

1. Did the authors consider validating the simulation results with experimental findings? Given the goal of the paper is to solve the ambiguity seen in the literature comparing with experimental results seems to be the most direct way to establish the correct parameters. 
2. It is not clear to the reader what is the difference in the simulation parameters between micromachining and traditional machining. 
3. Finite element models may not be the best method to describe mechanisms at the micron scale as material grain structure plays a more important role. Did the authors consider mesoscale simulations in their comparisons?
4. More literature review is required as some relevant papers such as the one below have been omitted.
   • Calamaz, M., Coupard, D., Nouari, M., & Girot, F. (2011). Numerical analysis of chip formation and shear localisation processes in machining the Ti-6Al-4V titanium alloy. The International Journal of Advanced Manufacturing Technology, 52(9-12), 887-895.
5. Many terms have not been defined in the paper such a PEEQ (Fig 16). Some of the figures have fonts that are too small to read and missing units.

Author Response

Dear Reviewer 3

Thanks very much for your recognition of our recent research work. On behalf of all co-authors, we greatly appreciate your precious time and efforts that you have spent reviewing and commenting on our manuscript (ISSN 2075-4701). Your professional comments on our manuscript are of great value and significance for refining our paper. All changes made to the revised manuscript are marked using a yellow background. Point-to-point responses to the reviewers’ comments are in the uploaded attachment. 

Best regards
Zhongpeng Zheng

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Thank You for the responses. Good luck with the future multi-scale studies.