Review Reports - High-Efficiency Milling of Inconel 718 Superalloy: Effects of Cutting Conditions on Tool Life and Surface Roughness

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

machines-3868871

The manuscript “High Efficient Milling of Inconel 718 Superalloy -Effects of Cutting Conditions on Tool Life and Surface Roughness” explores the influence of cutting speed and feed rate on tool wear, chip formation, and surface quality during milling of the high-performance alloy Inconel 718. It highlights that optimal machining conditions balancing these parameters can enhance tool longevity and maintain high machining efficiency despite the material’s challenging properties.

However, the manuscript also has some limitations and weaknesses that need to be addressed and improved. Here are some specific recommendations and suggestions for each section of the manuscript:

1. The abstract itself contains no quantitative results summary.

2. The research gap is not clear and also the authors are stating that “there have been few studies on welding changes in intermittent cutting ...” but don’t cite the studies in their research gap paragraph.

3. The paper lacks a clear, dedicated aims paragraph. There's no concise statement of specific research objectives and expected contributions in the end of the Introduction section.

4. The current caption reads only “Figure 9. Elemental analysis by EPMA.” and omits the identities of panels (a), (b), (c), and (d).

5. The conclusions summarize the main findings but end abruptly; adding a short “Future Work” paragraph would signal next steps and practical impact.

The manuscript needs major revision before it can be considered for publication. The authors need to address all the recommendations and suggestions mentioned above to improve their manuscript.

Author Response

However, the manuscript also has some limitations and weaknesses that need to be addressed and improved. Here are some specific recommendations and suggestions for each section of the manuscript:

The abstract itself contains no quantitative results summary.

Response: Thank you for your comments. I revised abstract based on your comments.

The research gap is not clear and also the authors are stating that “there have been few studies on welding changes in intermittent cutting ...” but don’t cite the studies in their research gap paragraph.

Response: Thank you for your comments. The explanations were revised and added based on your comments and another Reviewer.

The paper lacks a clear, dedicated aims paragraph. There's no concise statement of specific research objectives and expected contributions in the end of the Introduction section.

Response: Thank you for your comments. The explanations were added in the end of the Introduction section based on your comments.

The current caption reads only “Figure 9. Elemental analysis by EPMA.” and omits the identities of panels (a), (b), (c), and (d).

Response: Thank you for your comments. The captions of panels (a), (b), (c), and (d) were added.

The conclusions summarize the main findings but end abruptly; adding a short “Future Work” paragraph would signal next steps and practical impact.

Response: Thank you for your comments. The future works and practical impact in conclusions were added.

Figures 5 and 6 have been deleted, so the subsequent figure numbers have been reduced by two each.

Reviewer 2 Report

Comments and Suggestions for Authors

The topic is relevant, but the article presents some technical inconsistencies and needs improvementThe abstract is too long. The abstract does not need a big introduction. The abstract needs to clearly state the authors' methodology, results, and conclusions.

Novelties and scientific contributions of the manuscript should be clearly stated in abstract and introduction.

- Literature review should be improved, making it broader and updated, including recent journal publications.

10.1115/1.4066954

10.1115/1.4066955

10.3390/ma17020443

10.1115/1.4065800

10.3390/coatings14030311

10.3390/ma17020443

Page 2, 20 and 21: The paragraph is too long. Please split the text into two or more paragraphs.

Methodology section, insert the meaning of acronyms (NC) used in the paper.

In Figures 3 and 4, some failure aspects are illustrated on the Rake and flank faces of the tool. Can these failures lead to the chipping process?

What equipment was used to obtain Figures 3 and 4? Give information about the equipment and the parameters analysis specification.

Page 4: Give information about SEM equipment (Manufacturer and specifications) and the parameters analysis specification.

Figure 6: The specimen was prepared before the SEM analysis. If so, please write in the methodology section the procedure.

Item 2.4: How many tools were used in this study? Explain how the experimental matrix was created? Were duplicate tests made?

Separate the methodologies for microscopic analysis. Separate them according to each stage of the study. Don't write everything in a single paragraph, as it may confuse the reader.

Since Figures 8, 9, and 10 are results in the results and discussion section.

Explain how to use EPMA?

Figure 10 is representative of the material welding on flank face? Explain the BUE on Figure 10.

Please rewrite all Figure legend explain correctly ewhta information can extract from the image.

Discuss how results may differ for larger cutter diameters, different coatings (e.g., Ti or Al) or coolant use. Explicitly note current limitations.

Author Response

See attached file.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This paper presents milling of Inconel 718 using TiAlN-coated carbide end mills, focusing on the effects of feed rate and cutting speed on the life of tool, welding, wear, and surface roughness. The investigation shows that high feed per tooth suppresses welding combined with low cutting speed reduces achieves longer tool life and higher milling efficiency as well as reduced wear, compared to high-milling speed. The paper is well structured, the comments and observations are given below:

The figures captions need to be more descriptive e.g. 1-6, 9, 10,
Were multiple repeats conducted for each condition for accounting variability? If not, how was the reliability of the single measurement ensured?
The only roughness parameter chosen was Ra, what was the reason behind that? With the inclusion of Rz and 3D surface matrices may improve the methodology and results.
What standards were chosen for the tooling life? why use 0.1 mm flank wear / 0.2 mm chipping criteria?
Only 4-flute-coated tool geometry was tested, how the results extended to variable helix or different coatings?
Authors mentions low cutting speed and high feed as optimal, the trade-off in terms of surface quality degradation vs. productivity should also be quantified.

Author Response

See attached file.

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

A brief summary:

The aim of the paper was to investigate the influence of cutting speed and feed rate on tool life and surface roughness during high efficient milling of Inconel 718. Author conducted experimental tests in order to determine the most favorable cutting conditions. Research provides insight into tool wear and adhesion conditions, tool life and efficient cutting conditions. Author found that by keeping the low cutting speed and increasing feed, it was possible to achieve both high process efficiency and long tool life.

Broad comments:

A significant achievement of the presented work is conducting experimental research into tool life and surface roughness depending on process efficiency during milling of Inconel 718. Experimental tests allowed to establish relationships between cutting parameters and surface roughness and tool wear. The introduction is well written, albeit quite short. It could be improved by mentioning other machining methods and their efficiency in comparison with milling. The research design and methods are mostly appropriate and clearly described. The literature references are numerous and mostly up to date. The editing of the paper is fine, with very few minor typos that should be addressed.

Specific comments:

Line 72: Author write that “there has been little study on Inconel 718 superalloy concentrating on the feed rate, and attention has been paid to the feed rate rather than the cutting speed.” Author should address this contradiction, possibly translation error.
Table 1: what is the point of including the freezing point in the table (which Author wrote as N/A)?
Author keeps mixing tenses, i.e. line 109 “…was used. The tool is…”
Figures 5 and 6 seem to be quite redundant. Figure 7 give the same info that is included in Figure 5
Authors assumed table feed rate as an index of milling efficiency. While it is not wrong considering machining with a single end mill in this study, it would be beneficial and made research more applicable if Author presented the efficiency in terms of machining volume.
Why Author decided no to use any design of experiment and create any mathematical models to describe the dependencies between input and output variables?
Figure 11: notation of the last letter on the horizontal axis should be: i.
The scale on any of the EPMA images is completely indecipherable.
Figure 27 in Discussion constitutes merely the dependencies that can be calculated without any experimental research. Much more interesting to the reader would be a graph which would illustrate how tool life and how surface roughness were affected by the changes in machining efficiency. This is the point of the paper and there are no graphs in the paper that would illustrate it, only graphs showing tool life and surface roughness depending on machining parameters, which do not present as clearly the influence of machining efficiency on those output variables.

Author Response

See attched file.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I would like to thank the authors for their responses and revisions to the manuscript entitled “High Efficient Milling of Inconel 718 Superalloy -Effects of Cutting Conditions on Tool Life and Surface Roughness” .

The paper has improved in clarity and structure; however, several issues remain that should be addressed before the manuscript can be accepted for publication.

1. Abstract – Lack of Quantitative Results and Ambiguous Terminology

Although the abstract was revised, it still does not include a quantitative summary of the main experimental results. These data are important for illustrating the magnitude of the observed effects.

3. Aims and Objectives

While the Introduction now includes sentences describing the scope of the experiments, it still lacks a dedicated and well-structured Aims/Objectives paragraph that clearly summarizes the goals and expected contributions of the study.

5. Conclusions and Future Work

The authors have added a “Future Work” remark; however, the final sentence remains vague

"When the results will be applied to complex shape structure of Inconel 718 superal-480 loy in the future, aerospace industry will develop more and more".

This statement needs clarification. What specific application does the authors refer to? How exactly would the findings contribute to advancements in aerospace industry?

Recommendation: Minor Revision

Author Response

Thank you for your comments again. Please see attached file.

K. Kawasaki

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript “High Efficient Milling of Inconel 718 Superalloy-Effects of Cutting Conditions on Tool Life and Surface Roughness´ aims to clarify the effects of cutting speed and feed rate on tool chipping, tool wear, surface roughness of the workpiece, coating damage, and welding. The results were compared and conclusion were drawn. The new version of the manuscript has been reviewed by the authors. All comments made by this reviewer have been taken into account and significantly improved the content of the article. The article can be accepted and published as is.

Author Response

I revised the manuscript again

Reviewer 4 Report

Comments and Suggestions for Authors

Author has provided all the necessary explanations and have made corrections to the manuscript according to the suggestions

Author Response

I revised manuscript again.