Phase Equilibria in the Fe-Mo-Co System: Experimental Investigation and Thermodynamic Calculation

Round 1

Reviewer 1 Report

Seem:

a) The work has relevance and scientific merit and is very interesting, because it deals with the study of the phase equilibrium of a high-performance Fe-Mo-Co alloy and the evolution of the microstructure during the manufacturing processes. In order for the work to be published, some modifications need to be made.

b) Summary meeting the objectives of the work.

c) The introduction and review of the literature meet the objectives of the work; However, a further review of the literature of the last 05 years should be included.

d) Methodology is well written.

e) All Figures - They need to be better discussed with data from the literature of the last 05 years.

f) Conclusion - meet the objectives of the work.

g) This reviewer understands that the work should be published after modifications.

Author Response

1. a) The work has relevance and scientific merit and is very interesting, because it deals with the study of the phase equilibrium of a high-performance Fe-Mo-Co alloy and the evolution of the microstructure during the manufacturing processes. In order for the work to be published, some modifications need to be made.

Answer: According to your suggestion, some modifications have been made.

1. b) Summary meeting the objectives of the work.

Answer: According to your suggestion, the summary has been rewritten.

As a kind of high performance tool material, the phase relationship and microstructure evolution of Fe-Mo-Co alloy during manufacturing processes deserve attention and study. In the present work, isothermal sections of the Fe-Mo-Co system at 800 and 1350 ℃ were investigated using equilibrium alloy method and diffusion couple technology. No ternary compounds were found in both isothermal sections. Four three-phase regions and two three-phase regions were determined at 1350 and 800 ℃, respectively. The μ-Fe₇Mo₆ phase presents a continuous solid solution in the two isothermal sections. A set of self-consistent thermodynamic parameters of Fe-Mo-Co ternary system were obtained. The calculated results using the obtained thermodynamic parameters are in good agreement with the experimental results.

1. c) The introduction and review of the literature meet the objectives of the work; However, a further review of the literature of the last 05 years should be included.

Answer: According to your suggestion, new literature of the last 05 years have been added and described.

1. Gupta, M. K.; Sood, P. K.; Sharma, V. S., Optimization of machining parameters and cutting fluids during nano-fluid based minimum quantity lubrication turning of titanium alloy by using evolutionary techniques. Journal of Cleaner Production 2016, 135, 1276-1288.
2. Bordin, A.; Sartori, S.; Bruschi, S.; Ghiotti, A., Experimental investigation on the feasibility of dry and cryogenic machining as sustainable strategies when turning Ti6Al4V produced by Additive Manufacturing. Journal of Cleaner Production 2017, 142, 4142-4151.
3. Niketh, S.; Samuel, G. L., Surface texturing for tribology enhancement and its application on drill tool for the sustainable machining of titanium alloy. Journal of Cleaner Production 2017, 167, 253-270.
4. Tillmann, W.; Stangier, D.;  Meijer, A.;  Krebs, E.;  Ott, A.;  Platt, T.;  Lopes Dias, N. F.;  Hagen, L.; Biermann, D., Adapting the Surface Integrity of High-Speed Steel Tools for Sheet-Bulk Metal Forming. Journal of Manufacturing and Materials Processing 2022, 6 (2).
5. Prasad, K. N.; Syed, I., Surface Texturing and Laser Shock Peening Processes on High-Speed Steel Tool for Sustainable Machining. Arabian Journal for Science and Engineering 2021, 47 (7), 8589-8600.
6. Zhang, X.; Sun, H.; Gao, S.; Luo, Y., Processing Fundamentals and Performance Investigation of Selective Laser Melting of High-Speed Steel in Reactive N₂ Atmosphere. steel research international 2023, 94 (6).
7. Hong, X. D.; Zheng, H. R.; Liang, D., Field emission behavior of titanium alloy nanosheets. Materials Letters 2021, 304.
8. Liu, W.; Li, G.; Shao, Z.; Wu, X.; Ma, G.; Wang, F., Advance in experimental research on cutting temperature of titanium alloys. The International Journal of Advanced Manufacturing Technology 2023, 126 (5-6), 1827-1844.
9. Chen, Y.; Wu, W.; Dai, H., Overview of titanium alloy cutting based on machine learning. The International Journal of Advanced Manufacturing Technology 2023, 126 (11-12), 4749-4762.
10. Schröders, S.; Sandlöbes, S.; Berkels, B.; Korte-Kerzel, S., On the structure of defects in the Fe₇Mo₆ μ-Phase. Acta Materialia 2019, 167, 257-266.
11. Schröders, S.; Sandlöbes, S.; Birke, C.; Loeck, M.; Peters, L.; Tromas, C.; Korte-Kerzel, S., Room temperature deformation in the Fe₇Mo₆ μ-Phase. International Journal of Plasticity 2018, 108, 125-143.
12. Xie, F.; He, Y.; Yuan, Z.; Kang, X., Microstructure and high-temperature sliding wear performance of Fe-Co-Mo alloy coating fabricated by plasma cladding. Surface and Coatings Technology 2022, 444, 128667.
13. Yang, G.; Yin, H.; Deng, Z.; Zhang, C.; Zhang, R.; Qu, X., Effect of chemical composition on the microstructure and mechanical properties of MoCoB based cermets. Ceramics International 2020, 46 (11), 18046-18055.
14. Ren, N.; Zhang, J., Site preference and alloying effect of tungsten in the μ phase of Co₇Mo₆. Philosophical Magazine Letters 2015, 96 (1), 1-8.
15. Sun, Y.; Ganin, A. Y., The Synergistic Effects of Alloying on the Performance and Stability of Co₃Mo and Co₇Mo₆ for the Electrocatalytic Hydrogen Evolution Reaction. Hydrogen 2020, 1 (1), 11-21.
16. Peng, Z. Y.; Wang, X. M.; Yin, F. M.; Ouyang, X. M.; Hu, J. X., Phase equilibria of Co-Mo-Zn ternary system. Transactions of Nonferrous Metals Society of China 2020, 30 (2), 417-427.
17. Li, P.; Zhang, J.; Ma, S.; Zhang, Y.; Jin, H.; Mao, S., First-principles investigations on structural stability, elastic and electronic properties of Co₇M₆ (M= W, Mo, Nb) µ phases. Molecular Simulation 2019, 45 (9), 752-758.
18. Khimich, M. A.; Ibragimov, E. A.; Tolmachev, A. I.; Chebodaeva, V. V.; Uvarkin, P. V.; Saprykina, N. A.; Saprykin, A. A.; Sharkeev, Y. P., Influence of thermal treatment duration on structure and phase composition of additive Co-Cr-Mo alloy samples. Letters on Materials 2022, 12 (1), 43-48.

 

1. d) Methodology is well written.

Answer: According to your suggestion, the methodology part has been polished.

1. e) All Figures - They need to be better discussed with data from the literature of the last 05 years.

Answer: The phase relations of the Fe-Co-Mo system is seldom reported. So it is hard to make a comparative analysis with the literature of the last 05 years.

1. f) Conclusion - meet the objectives of the work.

Answer: According to your suggestion, the conclusion has been rewritten.

In this work, two isothermal sections at 1350 and 800 °C of the Fe-Mo-Co system were systematically established. No ternary compounds were found in both isothermal sections. Four three-phase regions and two three-phase regions were determined at 1350 and 800 ℃, respectively. The μ-Fe₇Mo₆ phase as the enhanced phase in the Fe-Co-Mo cutting tool material presents a continuous solid solution in the two isothermal sections. Based on the experimental data and binary parameters, the thermodynamic assessment of Fe-Co-Mo system was performed. The calculated results can provide theoretical support for optimization of composition and heat treatment process for Fe-Co-Mo alloy as a tool steel.

1. g) This reviewer understands that the work should be published after modifications.

Thank you.

Thanks for the reviewer’s suggestion.

Reviewer 2 Report

The Authors, after analysing the literature and the state of the art, put forward the interesting thesis that it is possible to use a three-component system to improve the cutting process of titanium alloys.

The aim of the work was to determine the phase equilibrium in Fe-Mo-Co system 800°C and 1350°C, and develop a set of self-consistent thermodynamic parameters of Fe-46 Mo-Co system using CALPHAD.

For the purpose of the article, a detailed analysis of available scientific articles was carried out. The Authors showed a multitude of studies but concerning binary systems.

The description of the experiments is accurate and contains all the necessary information for their verification.

The literature review contains relevant items, demonstrating the innovative nature of the research described in the article.

 Comments related to the article:

1. Why did the Authors perform annealing of the alloy at 1350°C? This should be explained further to the readers?

2) An analogous question applies to the experiments carried out at 800°C.

3. Whether the results obtained from the model used in CALPHAD were verified by examining the mechanical properties of the alloys obtained?

Author Response

The Authors, after analysing the literature and the state of the art, put forward the interesting thesis that it is possible to use a three-component system to improve the cutting process of titanium alloys.

The aim of the work was to determine the phase equilibrium in Fe-Mo-Co system 800°C and 1350°C, and develop a set of self-consistent thermodynamic parameters of Fe-46 Mo-Co system using CALPHAD.

For the purpose of the article, a detailed analysis of available scientific articles was carried out. The Authors showed a multitude of studies but concerning binary systems.

The description of the experiments is accurate and contains all the necessary information for their verification.

The literature review contains relevant items, demonstrating the innovative nature of the research described in the article.

Thanks for the reviewer’s comments.

 Comments related to the article:

1. Why did the Authors perform annealing of the alloy at 1350°C? This should be explained further to the readers? 2) An analogous question applies to the experiments carried out at 800°C.

Answer: According to the literature, the sintering temperature Fe-Co-Mo alloy is about 1350 °C. The highest temperature reached by the cutting tool is about 800 °C。

2. Whether the results obtained from the model used in CALPHAD were verified by examining the mechanical properties of the alloys obtained?

Answer: This paper mainly aims at the correlation measurement and thermodynamic calculation of the system, and then selects the alloy according to the calculation result to carry on the mechanical property test.

Reviewer 3 Report

The manuscript with the title “Phase equilibria in the Fe-Mo-Co system: Experimental investigation and thermodynamic calculation" presents an interesting contribution to the materials synthesis area. In addition, the manuscript is well designed and easy to follow. The applied methodology is adequate. However, the literature cited is outdated. It deserves publication in Coatings after major revisions, according to the following comments:

1)     Do not use the words in the title as your keywords. Change the keyword “Phase equilibria” and “Fe-Mo-Co”. Besides, SEM-EDS and X-ray diffraction are not a keyword. Provide more innovative keywords.

2)     Improve academic English throughout the manuscript. Avoid overused of “which”. There are 13 in the article.

3)     Remove acronyms that are not used in the abstract, such as SEM, EDS, EPMA, XRD.

4)     Add a space between the number and °C.

5)     The quality of the graphics in Figure 1 needs to be improved. Increase the font size of the axes.

6)     Format references according to journal guidelines. There are several references that are not in the format.

7)     Only 5 references out of 31 present less than 10 years of publication. Authors should seek to add recent studies. At least 50% of references are expected to be less than 10 years old. Add current studies.

8)     The fourth column of table 4 can be removed.

9)     A conclusion section should not discuss the main results. A conclusion brings what the authors conclude with the results of the article. What advance did the article bring to this area? Rewrite the section.

Improve academic English throughout the manuscript. Avoid overused of “which”. There are 13 in the article.

Author Response

The manuscript with the title “Phase equilibria in the Fe-Mo-Co system: Experimental investigation and thermodynamic calculation" presents an interesting contribution to the materials synthesis area. In addition, the manuscript is well designed and easy to follow. The applied methodology is adequate. However, the literature cited is outdated. It deserves publication in Coatings after major revisions, according to the following comments:

Thanks for the reviewer’s comments.

1) Do not use the words in the title as your keywords. Change the keyword “Phase equilibria” and “Fe-Mo-Co”. Besides, SEM-EDS and X-ray diffraction are not a keyword. Provide more innovative keywords. 

Answer: The keywords have been changed to “Phase relationship; equilibrium alloy; thermodynamic modeling; CALPHAD”.

2) Improve academic English throughout the manuscript. Avoid overused of “which”. There are 13 in the article. 

Answer: Thank you for your suggestion. The sentences including“which” have been changed.

3) Remove acronyms that are not used in the abstract, such as SEM, EDS, EPMA, XRD.

Answer: According to your suggestion, the acronyms in the abstract have been deleted.

4) Add a space between the number and °C.  

Answer: Thank you for your suggestion. The spaces between the number and °C have been added.

5) The quality of the graphics in Figure 1 needs to be improved. Increase the font size of the axes.   

Answer: According to your suggestion, the figure 1 has been redraw.

6) Format references according to journal guidelines. There are several references that are not in the format. 

Answer: The format of the references has been checked and amended.

7) Only 5 references out of 31 present less than 10 years of publication. Authors should seek to add recent studies. At least 50% of references are expected to be less than 10 years old. Add current studies. 

Answer: The development of binary phase diagrams spans a long time. When it is described in detail, the references cited are older. We have revised the references to refer to the most recent ones as much as possible.

8) The fourth column of table 4 can be removed.  

Answer: According to your suggestion, the fourth column of table 4 has been removed.

9) A conclusion section should not discuss the main results. A conclusion brings what the authors conclude with the results of the article. What advance did the article bring to this area? Rewrite the section.

Answer: According to your suggestion, the conclusion has been rewritten as shown below.

In this work, two isothermal sections at 1350 and 800 °C of the Fe-Mo-Co system were systematically established. No ternary compounds were found in both isothermal sections. Four three-phase regions and two three-phase regions were determined at 1350 and 800 ℃, respectively. The μ-Fe₇Mo₆ phase as the enhanced phase in the Fe-Co-Mo cutting tool material presents a continuous solid solution in the two isothermal sections. Based on the experimental data and binary parameters, the thermodynamic assessment of Fe-Co-Mo system was performed. The calculated results can provide theoretical support for optimization of composition and heat treatment process for Fe-Co-Mo alloy as a tool steel.

Round 2

Reviewer 1 Report

All modifications suggested by the reviewer have been made. The article may be published.

Reviewer 3 Report

The authors performed all suggested revisions. Therefore, the manuscript must be accepted.