Cutting Performance and Tool Wear of AlCrN- and TiAlN-Coated Carbide Tools during Milling of Tantalum–Tungsten Alloy

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1.        The abstract should summarize the key points of the research, avoiding excessive detail. For instance, mentioning the "KDVM800LH vertical machining center" should only be done if the choice of this equipment is of particular significance. The abstract should clearly highlight the main findings of the research and their importance. Although the text mentions a comparison of the performance of AlCrN and TiAlN coated tools, these findings could be more explicitly outlined in terms of their specific significance to the relevant fields;

2.        Chapter 2: The manuscript briefly addresses the hardness and yield strength of Ta-2.5W, yet it omits a critical discussion on the methodologies employed to ascertain these parameters. For the sake of completeness and to increase the credibility of the findings, it is recommended that the authors detail the specific techniques and procedures used to measure these properties;

3.        The data points presented in Figure 2 lack error bars, failing to illustrate that these values are averages derived from multiple datasets. It is strongly recommended to supplement with relevant data to address this issue. Additionally, Figures 3 and 4 require repositioning to display a clearer and more accurate magnification of ×200. Regarding Figures 5 and 6, the scanning electron microscope images intended to show the wear of AlCrN and TiAlN coated cutting tools do not adequately reveal the wear patterns and the micro-details of tip wear. I suggest providing images with higher magnification or annotating the current images with clearer localized magnified views to better illustrate these details;

4.        Page 5, line 9: The conclusion proposed here lacks a detailed mechanism analysis to substantiate the viewpoint presented. It is recommended that this conclusion would be more appropriately included in Section 3.3;

5.        Section 3.4: please further discuss the possible reasons for the differing sensitivities of TiAlN coated tools and AlCrN coated tools to surface roughness under the same cutting conditions;

6.        Chapter 4: While the conclusion lists some results, it lacks sufficient explanation or theoretical support for why these phenomena occur. For instance, why do AlCrN coated tools perform better in terms of cutting force and surface roughness, and what principles lead to this outcome? Providing more theoretical explanations could enhance the persuasiveness of the conclusions. In this chapter, when stating “When milling Ta-2.5W within the selected range of cutting parameters…,” it is suggested to specify the range of parameters. Try to avoid overly absolute statements such as “…mainly exhibit adhesive wear with slight diffusion wear”.

Comments on the Quality of English Language

1.        Chapter 1,"However, the cutting mechanism of Ta-2.5W is not clear due to less research work on that.". The expression "on that" is not clear;

2.        Chapter 1, "The main objective of this study...wear mechanisms are presented", please reduce repetitive expressions in the text and improve sentence fluency and directness；

3.        Chapter 2, "The main chemical composition of the Ta-2.5W is presented in...", suggesting a more appropriate replacement for "presented".;

4.        Chapter 2, the phrase "The data was displayed on a laptop using…" should use "were" as in "The data were displayed on a laptop using…"；

5.        Section 3.1, paragraph 1, line 3, "take the forces" is unclear and it is suggested that it be replaced with a clearer form of the verb;

6.        Section 3.1, paragraph 2, lines 3-4, "As can be seen from the figure...", remove unnecessary passive voice;

7.        Page 4, lines 11-12: Repeated use of "additionally" and "due to", suggesting other words;

8.        Section 3.2, paragraph 1, line 7: "This surface is more prone to ... the cutting edge, resulting in ..." lacks clarity of subject reference;

9.        Section 3.2, "... the surface quality and dimension accuracy of the machined surface would be affected ...", the tense of the sentence is inconsistent；

10.    Section 3.3, paragraph 2, line 11, "AGrN" is misspelled.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The reviewer believes that this study is very practical and could be of great importance to industry. However, from a scientific point of view, the results are too sparse and there are many problems with the design of the experiment.
I have several questions and comments for the authors:
The dynamometer frequency was only 2 kHz. Why? Surely there were only a few samples per one egage for the higher cutting speed. The data must have been heavily skewed (sort of like a filter) and most likely incorrect. This could explain such small forces. Could you provide a recording of the cutting force measurements and describe how you measured the forces from the signal.
The tower you built on Kistler 9257b could also greatly affect the results. A large weight causes a significant change in the natural frequency of the dynamometer as well as the damping. On the other hand, too high a height causes a tilting moment. I think this setting has strong effect on the cutting force measurement.
What was the path of the cutting tool? Was it a spiral, a circle or a straight line?
Cutting conditions are unlikely to be suitable for both tool types when the cutting edge or coating fails. When did you see the first signs of chipping or breaking? Or did you only take two tool wear measurements?

Author Response

Thanks for your comments, please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

machines-2863955

The manuscript with a title “Cutting Performance and Tool Wear of AlCrN and TiAlN Coated Carbide Tools During Milling of Tantalum-Tungsten Alloy” presents a study that examines the machining performance of coated carbide tools in milling Ta-2.5W alloy. It focuses on the effects of AlCrN/TiAlN coatings on cutting forces, tool wear, and surface roughness. The study finds that AlCrN coated tools exhibit lower cutting forces and better wear resistance compared to TiAlN coated tools, attributing the main wear mechanisms to crater wear, adhesive wear, and diffusion wear. The topic is relevant and important.

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:

Abstract

1.    The abstract lacks specific quantitative results, such as exact percentages or values for the reduction in cutting forces or improvement in wear resistance, which would enhance its informativeness and usefulness for readers seeking detailed insights into the study's outcomes.

Results and discussion

2.   It would be beneficial to include a comparative analysis with existing literature to highlight the novelty and significance of the findings.

Conclusions

3.     Future research directions could be suggested.

The manuscript needs minor 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

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Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The pictures you provided reveal that you really have few points in one engagement (very sharp peaks in the picture indicate this). However, more detailed pictures where individual engagements could be seen would prove it better. In my estimation, you could lose up to 20% of the magnitude of the force at the highest cutting speed, while at a low cutting speed the error would be significantly smaller, possibly negligible. Therefore, one cannot rely too much on absolute values. Damping due to the large mass on the dynamometer could imply similar errors. Never the less, despite the fact that the method of measurement and evaluation used does not reveal anything about the resultant force of the cutting edge in the engagement, it is used equally for both types of coatings. So it is possible to compare the presented data at least relatively to each other.
I am asking for corrections in the text that will take this fact into account. I would prefer more general formulations in conclusion and in the main body, such as: for milling this alloy one could use low cutting speeds, small feeds, etc.. Compared to specific values, which are unreliable for me.

It would be appropriate to mention which tool paths were used in the text.

I would also like to read if the results of the force measurements could also be significantly affected by wear, which you assume is faster for higher cutting speeds. It would depend on when you measured the forces.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 3

Reviewer 2 Report

Comments and Suggestions for Authors

ok