The Effect of Yttrium Addition on Microstructure and Mechanical Properties of Refractory TiTaZrHfW High-Entropy Films

Round 1

Reviewer 1 Report

coatings-2537546

Effect of yttrium addition on microstructure and mechanical properties of refractory TiTaZrHfW high entropy films

 

Authors have done a worth investigation to study the effect of yttrium on high entropy films. Experimental studies like SEM, EDS, XRD, TEM and nanoindentation were explored in detail and produced good scientific results. Some of my concerns are as follows:

Ø  Clearly define main contribution of your study in the last paragraph of introduction.

Ø  Abstract, in the beginning, the research background should be given. In addition, the authors should provide more research results and conclusions, so that readers can better understand the main research work of this paper.

Ø  What is the major inference from this study? It should be clearly explained in the abstract and last paragraph of introduction section.

Ø  How does the obtained thermodynamic criteria validate the current investigation.

Ø  Some of the important publications related to this study should be referred and cited in the manuscript;

https://doi.org/10.1016/j.intermet.2021.107405; https://doi.org/10.1016/j.ijrmhm.2022.105946;

https://doi.org/10.3390/met11071024; https://doi.org/10.1007/s12633-019-00370-8

Ø  What is the reason for increase in modulus with reduced strength for two compositions compared to other? Will the hardness play any role in it?

Ø  Does the grain size have any impact on the obtained results?

Ø  How do you conform the phase transformation without studying the metallurgical properties of the alloy?

 

All the comments need to be addressed very carefully by considering the technical depth of the manuscript. I, as a reviewer of this manuscript, will accept this quality manuscript for publication after implementing all the major corrections.

The linguistic level and the mechanics of English writing are not appropriate for publication. There are few grammatical and typing errors in the manuscript, so please check and revise. The way of writing is not clear and it is difficult for the readers to understand. The paper should be rewritten and proofread again thoroughly. Extensive editing of English language is required.

Author Response

Authors thank the Reviewer for these comments.

 

R1_Q1: Clearly define main contribution of your study in the last paragraph of introduction.

Answer to R1_Q1: The main contribution of the study is now clearly defined at the end of the introduction.  

 

R1_Q2: Abstract, in the beginning, the research background should be given. In addition, the authors should provide more research results and conclusions, so that readers can better understand the main research work of this paper.

Answer to R1_Q2: The abstract and the conclusion are improved.  

 

R1_Q3: What is the major inference from this study? It should be clearly explained in the abstract and last paragraph of introduction section.

Answer to R1_Q3: The study reports on yttrium effect on the microstructure and mechanical properties of TiTaZrHf refractory high entropy films. The text is improved in the revised version. 

 

R1_Q4: How does the obtained thermodynamic criteria validate the current investigation.

Answer to R1_Q4: The thermodynamic criteria can help to predict of the formation of new phases of the alloys. In this study, ΔS, Ω and δ were calculated and the results are presented as function of yttrium content. These parameters reveal the formation of solid solution at low Y content while at high Y content metallic compounds are formed. The calculation is consistent with XRD and TEM results. The related text is improved in the revised version.

 

R1_Q5: Some of the important publications related to this study should be referred and cited in the manuscript;

https://doi.org/10.1016/j.intermet.2021.107405; https://doi.org/10.1016/j.ijrmhm.2022.105946;

https://doi.org/10.3390/met11071024; https://doi.org/10.1007/s12633-019-00370-8

Answer to R1_Q5: Three references are added to the revised version. One reference reports on cutting tools development under cryogenic process which hardly correspond to aim of this study and more generally to HEA.  

 

R1_Q6: What is the reason for increase in modulus with reduced strength for two compositions compared to other? Will the hardness play any role in it?

Answer to R1_Q6:  The two compositions TiTaZrHfW_0.50Y_0.50 and TiTaZrHfW_0.44Y.56 have quasi-similar values of the modulus, 80.55 and 82 GPa. The difference lies within the error bar.

 

R1_Q7: Does the grain size have any impact on the obtained results?

Answer to R1_Q7: Yes, as Y content increases, more nano-grains are formed (ones within others at high Y content) which weakening the films leading to the reduction of hardness and young modulus decrease. This is added in section 3.6   

 

R1_Q8: How do you conform the phase transformation without studying the metallurgical properties of the alloy?

Answer to R1_Q8: The two phases are formed depending on Y content and they are confirmed by XRD and TEM analysis. The films with low Y amount show diffractograms with one halo-shaped peak revealing amorphous structure. TEM show the formation of nano-grains with fcc and hexagonal structure according to Y content. This is discussed in the new version. 

 

R1_Q9: The linguistic level and the mechanics of English writing are not appropriate for publication. There are few grammatical and typing errors in the manuscript, so please check and revise. The way of writing is not clear and it is difficult for the readers to understand. The paper should be rewritten and proofread again thoroughly. Extensive editing of English language is required.

Answer to R1_Q8: The manuscript is revised and the language is improved.

Reviewer 2 Report

In this work, the authors studied the effect of Y content in a new refractory TiTaZrHfW equimolar film on microstructural and mechanical properties. Thus, it can be recommended for publication in the journal of “Coatings” after the following addressed:

(a) All results need in-depth discussion and correlation with the literature;

(b) Show better statistical detail about the ideal condition of the photocatalysis process, such as compound central rotational design (CCRD), as well as correlations between photocatalytic activity and characterization results, such as SPSS Statistics;

(c) Further characterization techniques are needed such as FTIR, ATR-FTIR, N₂ porosimetry and zeta potential.

Author Response

Authors thank the Reviewer for these comments.

 

R2_Q1: All results need in-depth discussion and correlation with the literature;

Answer to R1_Q8: The manuscript is revised and the text is improved in the new version.

 

R2_Q2:

(b) Show better statistical detail about the ideal condition of the photocatalysis process, such as compound central rotational design (CCRD), as well as correlations between photocatalytic activity and characterization results, such as SPSS Statistics;

(c) Further characterization techniques are needed such as FTIR, ATR-FTIR, N2 porosimetry and zeta potential

R2_Q2, b and c: Authors do not understand the question of the Reviewers. There is no photocalysis phenomenon in this study. The objective is the study of yttrium effect on the microstructure and the mechanical properties of TiTaZrHfW refractory high entropy films.

Reviewer 3 Report

The manucript provides an overview of the study on the effects of yttrium (Y) addition as a rare earth element on the microstructure and mechanical properties of TiTaZrHfW refractory high entropy films (HEFs). The manucript covers the key points of the study; however, there are areas that can be improved for clarity and precision. Here are specific suggestions for modification:

1.      Introduction:

Provide a more comprehensive introduction to the importance of refractory high entropy films and the role of yttrium as a rare earth element in modifying their microstructure and mechanical properties;

Clearly state the objectives of the study, which are to investigate the influence of yttrium content on the microstructure and mechanical properties of TiTaZrHfW HEFs and to analyze the phase evolution using thermodynamic criteria;

Emphasize the significance of the study in advancing the understanding of rare earth element doping in high entropy films and its potential applications in developing coatings with improved high-temperature oxidation resistance.

2.      Experimental details:

Provide more details about the specific deposition technique and parameters used to fabricate the (TiTaZrHfW)100-xYx films, including the magnetron sputtering process and the range of Y content variations;

Specify the characterization techniques employed, such as SEM-EDS, XRD, TEM, and nanoindentation, and briefly explain their purpose in analyzing the microstructure and mechanical properties of the films;

Quantify the results obtained from the characterization techniques, such as grain size measurements, phase identification, and hardness and Young's modulus values, along with their corresponding Y content variations.

3.      Results and Discussion:

Organize the results in a more structured manner, discussing the microstructural evolution and phase formation as a function of Y content in the TiTaZrHfW films;

Clearly explain the observed changes in the grain size, phase composition, and mechanical properties of the films with increasing Y content, emphasizing the influence of Y on the formation of nanocomposites and the resulting grain size coarsening;

Discuss the TEM and XRD results in relation to the identification of L12 and Y-hexagonal structures, and their consistency with the observed microstructural changes;

Provide a more detailed explanation of the thermodynamic criteria (ΔHmix, ΔSmix, Ω, and δ) used to analyze the phase evolution and clarify their relevance to the formation of new metallic compounds.

4.      Conclusion:

Summarize the main findings of the study, highlighting the formation of nanocomposites and the phase evolution in the (TiTaZrHfW)100-xYx HEFs with varying Y content;

Clarify the relationship between the increase in grain size and the mechanical property deterioration in the films as a result of Y addition;

Discuss the potential implications of the study's findings, particularly the development of coatings with enhanced high-temperature oxidation resistance through the formation of nanoparticles by doping with rare earth elements, such as yttrium.

5.      Language and Style:

Review the entire manuscript for grammatical errors, clarity of expression, and scientific writing conventions;

Ensure consistent terminology throughout the manuscript, particularly when referring to the TiTaZrHfW films, yttrium, and the measured mechanical properties;

Consider rephrasing or restructuring sentences to improve the flow, readability, and logical progression of the whole manuscript.

The manucript provides an overview of the study on the effects of yttrium (Y) addition as a rare earth element on the microstructure and mechanical properties of TiTaZrHfW refractory high entropy films (HEFs). The manucript covers the key points of the study; however, there are areas that can be improved for clarity and precision. Here are specific suggestions for modification:

1.      Introduction:

Provide a more comprehensive introduction to the importance of refractory high entropy films and the role of yttrium as a rare earth element in modifying their microstructure and mechanical properties;

Clearly state the objectives of the study, which are to investigate the influence of yttrium content on the microstructure and mechanical properties of TiTaZrHfW HEFs and to analyze the phase evolution using thermodynamic criteria;

Emphasize the significance of the study in advancing the understanding of rare earth element doping in high entropy films and its potential applications in developing coatings with improved high-temperature oxidation resistance.

2.      Experimental details:

Provide more details about the specific deposition technique and parameters used to fabricate the (TiTaZrHfW)100-xYx films, including the magnetron sputtering process and the range of Y content variations;

Specify the characterization techniques employed, such as SEM-EDS, XRD, TEM, and nanoindentation, and briefly explain their purpose in analyzing the microstructure and mechanical properties of the films;

Quantify the results obtained from the characterization techniques, such as grain size measurements, phase identification, and hardness and Young's modulus values, along with their corresponding Y content variations.

3.      Results and Discussion:

Organize the results in a more structured manner, discussing the microstructural evolution and phase formation as a function of Y content in the TiTaZrHfW films;

Clearly explain the observed changes in the grain size, phase composition, and mechanical properties of the films with increasing Y content, emphasizing the influence of Y on the formation of nanocomposites and the resulting grain size coarsening;

Discuss the TEM and XRD results in relation to the identification of L12 and Y-hexagonal structures, and their consistency with the observed microstructural changes;

Provide a more detailed explanation of the thermodynamic criteria (ΔHmix, ΔSmix, Ω, and δ) used to analyze the phase evolution and clarify their relevance to the formation of new metallic compounds.

4.      Conclusion:

Summarize the main findings of the study, highlighting the formation of nanocomposites and the phase evolution in the (TiTaZrHfW)100-xYx HEFs with varying Y content;

Clarify the relationship between the increase in grain size and the mechanical property deterioration in the films as a result of Y addition;

Discuss the potential implications of the study's findings, particularly the development of coatings with enhanced high-temperature oxidation resistance through the formation of nanoparticles by doping with rare earth elements, such as yttrium.

5.      Language and Style:

Review the entire manuscript for grammatical errors, clarity of expression, and scientific writing conventions;

Ensure consistent terminology throughout the manuscript, particularly when referring to the TiTaZrHfW films, yttrium, and the measured mechanical properties;

Consider rephrasing or restructuring sentences to improve the flow, readability, and logical progression of the whole manuscript.

Author Response

Authors thank the Reviewer for these comments.

1. Introduction:

R3_Q1: Provide a more comprehensive introduction to the importance of refractory high entropy films and the role of yttrium as a rare earth element in modifying their microstructure and mechanical properties;

Answer to R3_Q1: The introduction is revised and improved.

 

R3_Q2: Clearly state the objectives of the study, which are to investigate the influence of yttrium content on the microstructure and mechanical properties of TiTaZrHfW HEFs and to analyze the phase evolution using thermodynamic criteria;

Answer to R3_Q2: The manuscript is revised and the objective of the study is clearly stated in the new version. 

 

R3_Q3: Emphasize the significance of the study in advancing the understanding of rare earth element doping in high entropy films and its potential applications in developing coatings with improved high-temperature oxidation resistance.

Answer to R3_Q3: The effect of rare earth elements on the oxidation and mechanical properties of HEFs is discussed and the manuscript is improved.  

 

2. Experimental details:

R3_Q4: Provide more details about the specific deposition technique and parameters used to fabricate the (TiTaZrHfW)100-xYx films, including the magnetron sputtering process and the range of Y content variations;

Answer to R3_Q4: Details of the experience are added to the revised version. 

 

R3_Q5: Specify the characterization techniques employed, such as SEM-EDS, XRD, TEM, and nanoindentation, and briefly explain their purpose in analyzing the microstructure and mechanical properties of the films;

Answer to R3_Q5: All characterization techniques are specified and the related results are improved.  

 

R3_Q6: Quantify the results obtained from the characterization techniques, such as grain size measurements, phase identification, and hardness and Young's modulus values, along with their corresponding Y content variations.

Answer to R3_Q6: The results obtained from the characterization technique are quantified and discussed in the manuscript. 

 

3. Results and Discussion:

R3_Q7: Organize the results in a more structured manner, discussing the microstructural evolution and phase formation as a function of Y content in the TiTaZrHfW films;

Answer to R3_Q7: The results are structured and the evolution of the microstructure is discussed in the new version.

 

R3_Q8: Clearly explain the observed changes in the grain size, phase composition, and mechanical properties of the films with increasing Y content, emphasizing the influence of Y on the formation of nanocomposites and the resulting grain size coarsening;

Answer to R3_Q8: The results are discussed and the related sections are improved.

 

R3_Q9: Discuss the TEM and XRD results in relation to the identification of L12 and Y-hexagonal structures, and their consistency with the observed microstructural changes;

Answer to R3_Q9: TEM and XRD results are discussed and improved regarding the microstructural changes.

 

R3_Q10: Provide a more detailed explanation of the thermodynamic criteria (ΔHmix, ΔSmix, Ω, and δ) used to analyze the phase evolution and clarify their relevance to the formation of new metallic compounds.

Answer to R3_Q10: The thermodynamic criteria are discussed and their relation to phases evolution is improved.

 

4. Conclusion:

R3_Q11: Summarize the main findings of the study, highlighting the formation of nanocomposites and the phase evolution in the (TiTaZrHfW)100-xYx HEFs with varying Y content;

Clarify the relationship between the increase in grain size and the mechanical property deterioration in the films as a result of Y addition;

Discuss the potential implications of the study's findings, particularly the development of coatings with enhanced high-temperature oxidation resistance through the formation of nanoparticles by doping with rare earth elements, such as yttrium.

Answer to R3_Q11: The conclusion is revised and improved in the new version.

 

5. Language and Style:

R3_Q12: Review the entire manuscript for grammatical errors, clarity of expression, and scientific writing conventions;

Ensure consistent terminology throughout the manuscript, particularly when referring to the TiTaZrHfW films, yttrium, and the measured mechanical properties;

Consider rephrasing or restructuring sentences to improve the flow, readability, and logical progression of the whole manuscript.

Answer to R3_Q12: The manuscript is revised, corrected and improved in the new version.  

Round 2

Reviewer 1 Report

I have gone through the manuscript completely and satisfied with the revision. As such, I will recommend this paper for publication in its present form.

 

Author Response

The authors would like to thank the Reviewer.

Reviewer 2 Report

All the comments were addressed and the manuscript can be accepted in its current form

Author Response

The authors would like to thank the Reviewer.

Reviewer 3 Report

Accept

Accept

Author Response

The authors would like to thank the Reviewer.