FEM Simulation of Surface Micro-Groove Structure Fins Produced by Cryogenic-Temperature Extrusion Machining

Round 1

Reviewer 1 Report

The paper contains new and significant information and the paper demonstrates an adequate understanding of the relevant literature in the field. However, the manuscript can be modified and needs substantial revision based on the following:

 1. This article fails to present the gaps and opportunities. I hope the authors could have demonstrated innovative point in their article.

 2. Exhaustive adequate and relevant Literature Review should be carried out. More recent literatures/references need to be added and properly discussed by highlighting the importance and limitations of the works reported.

 3. The authors need to provide a justification/rationale for selecting as well as limiting the variable inputs. The emphasis is more on methodology than the mechanism. No physical consideration of the process is seen in this article. 

 4. The paper is significantly lacking in scientific explanations for the observations reported. The engineering explanation should have been offered to justify the optimized results.

 5. One significant deficiency of the study is that the authors have not put their conclusions in perspective of the currently available literature. The major breakthrough of this study in relation to the existing knowledge could have been discussed.

 6. The “Conclusion” section is not acceptable as it contains merely a brief restatement of the work carried out. The entire point is to look at the major findings of the current study in relation to the existing knowledge, however qualitative/quantitative.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

This manuscript presents the effects of four parameters (compression ratio λ, rake angle of the tool α, friction coefficient μ and constraining tool corner radius R) investigated by FEM simulation of CT-EM and room temperature extrusion-cutting (RT-EM). The results show that the maximum effective stress and temperature of the fins decrease with the increase of λ and α, but increase with the increase of μ, and the effective stress of CT-EM is larger. The smaller λ and α are, the bigger the height and the cross-sectional area of fins are. At the λ of 0.7, the formability of fins produced by CT-EM is the best. When α is greater than 15°, the formability of CT-EM is better. With the increase of μ, the length of the fins decreases, but the cross-sectional area of CT-EM can also be improved. At the R of 0.1mm, the cross-sectional area of CT-EM is larger, but the effective stress, temperature and morphology of the fins change little under different value of R.

This paper presents reasonable structure and sufficient data. But some improvements are required before this manuscript can be considered for publication:

1. There are some grammar, format and word errors in this paper. Please revise the document and make the necessary modifications.

2. The drawing number (Figure 4(b), 6, etc ) is marked in the wrong order.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

The authors presented an article «FEM Simulation of Surface Micro-groove Structure Fins Produced by Cryogenic Temperature Extrusion-Machining». The authors are advised to consider the following comments for this paper.

 

·         Abstract

The abstract need to be improved. The abstract is written long. Shorten and core findings of the study should be given. Please provide the main quantitative and qualitative research core findings. Demonstrate in the abstract novelty, practical significance. Briefly list the input and output parameters of the research.

·         Introduction

Seemingly, a comprehensive literature review was given. However, they were just summarized one- by-one. The authors have to stop after writing each example and think about the contributions and lack of knowledge for each paper. After that, in the final lines of the introduction give the blank spots of the topic. Then it will be clear what did authors make differently from the open literature. More references should be included in the reference. Some key references were studied in several paper as follows: (I) An Overview of Deformation Path Shapes on Equal Channel Angular Pressing, (II) Large strain extrusion machining of magnesium alloys for biomedical applications, (III) Influence of extrusion parameters on drilling machinability of AZ31 magnesium alloy, (IV) An Experimental Investigation on Machinability of AZ31B Magnesium Alloy under Dry and Dipped Cryogenic Approaches, (V) Drilling of AZ31 Magnesium Alloy under Dry and Cryogenic Conditions.

In the last paragraph of the introduction section; What is the scientific novelty of the paper? What is the practical value? What makes this approach different from other researchers? Please specify. Gap and significance of the work must be included.

·         2. Establishment of finite element model

What are the standards used in the tests?

Describe the experimental and measurement procedure in more detail. At what point in time? How is the measuring set up?

Please provide more detailed basis and reference for selecting cutting parameters and their levels. Please specify.

A brief information about the cryogenic process and the temperatures at which it is carried out should be given.

“the mesh is locally refined in the cutting deformation zone, as shown in Figure 3.” Mesh properties in the shear zone should be detailed. Has the mesh size been optimized in this region?

·         3. Simulation results and analysis

It is useful to add explanations of parameters to the results obtained. At least five sentences for each Figures. The results obtained should be explained by supporting the literature.

How was the accuracy of the FEM results checked? Literature comparison, experimental verification, etc.

Figure 8, 14, 20 and  26 shows the cross-sectional shape of the three-dimensional morphology of micro-groove fins. The cross-sectional shape should be drawn on the actual form for a better understanding of the changes.

·         Conclusions

The conclusions need to be improved. It is necessary to more clearly show the novelty of the article. Add qualitative and quantitative results of your work. What is the difference from previous work in this area? Show practical relevance. What are the differences from previous works?

Suggestions should be made to increase the studies to be done in this field in conclusion section.

·         Authors should carefully study the comments and make improvements to the article step by step. All changes should be highlighted in color.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Authors have modified the manuscript by addressing most of the reviewer's comments and hence the manuscript can be accepted in its present form.