Combustion Synthesis of MAX Phases: Microstructure and Properties Inherited from the Processing Pathway

Round 1

Reviewer 1 Report

This is a very good review on the all routes of synthesis of MAX phase materials. It is a very vast field and a review on these methods was long overdue in the scientific literature. By the time I was dealing with this field I was missing such comprehensive reviews, to help me use the most appropriate synthesis route.

The paper can be considered for publication providing the following issues are properly addressed:

1. Tables 1 and 2 have the compositions written with elemental indexes not subscripted, as it is written in the text (for instance Ti3AlC2 should be Ti[sub3]AlC[sub2])

2. At the end of section 5. there is one extra sentence left from the explanatory template, so it should be removed.

3. There should also be a final section, Conclusion, that it is customary to have. At the present, this is missing.

 

Providing these issues are satisfactorily addressed, I recommend publication of this review paper.

English language is fine, I recommend a thorough rereading of the manuscript just to avoid mistypings.

Author Response

Reviewer 1

This is a very good review on the all routes of synthesis of MAX phase materials. It is a very vast field and a review on these methods was long overdue in the scientific literature. By the time I was dealing with this field I was missing such comprehensive reviews, to help me use the most appropriate synthesis route.

The paper can be considered for publication providing the following issues are properly addressed:

1. Tables 1 and 2 have the compositions written with elemental indexes not subscripted, as it is written in the text (for instance Ti3AlC2 should be Ti[sub3]AlC[sub2])

I highly appreciate reviewer’s comments and recommendations. All typo errors and indices were corrected.

 

2. At the end of section 5. there is one extra sentence left from the explanatory template, so it should be removed.

It was removed.

 

3. There should also be a final section, Conclusion, that it is customary to have. At the present, this is missing.

As it is common to present perspectives and conclusion sections together in reviews, by your favour, author prefers to present summary and outlook together. 

Reviewer 2 Report

The review article claims to be published the journal after elimination of minor comments:

1.The Title of the article must be corrected,the word protocol for the word analysis?the word critical review must be added.

2.It is necessary to add refferences to the first researchers of the Max-phases,but they are not indicated...

3.For an example,I am sending refferences to two review articles,{1,2} close in sbject matter to the review.

There are very few for review?there should be over 100 refferences,at least... The relevance of  the work is beyond doupt,the topic is interesting,you can publish after editing..

[1] Mxene-a new class of two-dimentional materials:  structure,properties and potential applications Nanomaterial,2021,11(12) 3412

[2]Polycaprolactone-MXene Nanofibrous Scaffolds for tissue Engineerings ACS Applied Mater.and Interfaces,2023,15,14033-14047

not bad

Author Response

Review 2

The review article claims to be published the journal after elimination of minor comments:

1.The Title of the article must be corrected,the word protocol for the word analysis?the word critical review must be added.

I highly appreciate reviewer’s comments and recommendations. The title was revised.

2.It is necessary to add references to the first researchers of the Max-phases,but they are not indicated...

References [1], [2], [3], [36], [91] directly refer to the first researches, [4], [5] and [6] – are comprehensive reviews that comprise all details from the first researches.

3.For an example,I am sending refferences to two review articles,{1,2} close in sbject matter to the review.

There are very few for review?there should be over 100 refferences,at least... The relevance of  the work is beyond doupt,the topic is interesting,you can publish after editing..

[1] Mxene-a new class of two-dimentional materials:  structure,properties and potential applications Nanomaterial,2021,11(12) 3412

[2]Polycaprolactone-MXene Nanofibrous Scaffolds for tissue Engineerings ACS Applied Mater.and Interfaces,2023,15,14033-14047

There are many works related to MXenes and MAX phases by different approaches; however SHS-produced ones were only selected in the current review.

Reviewer 3 Report

This manuscript reported the microstructure and properties inheritance in the combustion synthesis protocols of MAX phases. Accordingly, it delivers the main findings of the optimization of combustion synthesis of MAX phases and the influence of combustion wave on the microstructure features thereof. Therefore, it is recommended to be accepted after a major revision for this manuscript. The following questions need to be addressed for further improvement:

 

1. Detailed comparison and discussion on the cost of the optimized combustion synthesis are suggested.

2. The compositional characterization of MAX phase samples in recent articles need to be exhibited, which is favorable to understood and discerned.

3. The chapter 2 of the manuscript, which is too verbose, conclusive tables of the relevant features are suggested.

4. In the manuscript, the writing of words and grammatical problems need to be corrected, such as the consecutive use of multiple identical prepositions and the contextualization of chemical formulas.

5. The correction on the order of reference is suggested. It is possible to reduce the number of references cited in the preceding text by inserting them sequentially in the following text.

6. The presentation of the letters on the figures are not standardized, and the spacing of the figures is not controlled. Harmonization of formats for the above issues is suggested.

7. Some related works and form of writing may be helpful for this work, such as, Nano Research, 12, 471-487 (2019); Nano Research, 15, 6551-6567 (2022); Adv. Energy Mater, 2023, 13, 2203903.

Need for further simplification and standardization

Author Response

Review 3

This manuscript reported the microstructure and properties inheritance in the combustion synthesis protocols of MAX phases. Accordingly, it delivers the main findings of the optimization of combustion synthesis of MAX phases and the influence of combustion wave on the microstructure features thereof. Therefore, it is recommended to be accepted after a major revision for this manuscript. The following questions need to be addressed for further improvement:

 

1. Detailed comparison and discussion on the cost of the optimized combustion synthesis are suggested.

I highly appreciate reviewer’s comments and recommendations. The economic aspects are very important, however it was out of scope of the current research, hence I have considered only energetic favorability of SHS procedure. References [https://doi.org/10.21203/rs.3.rs-2817391/v1] and [Ref 6] comprise detailed analyses of that issue, and showed that the key pricing factor is the electricity consumed at their production. In particular, 45% of the price is coming from precursors, 40% is electricity, and 15% - milling, drying, characterization (human efforts and equipment were not considered). Hence, SHS-derived ones due to energy-efficiency cost about 2 times cheaper than MAX phases obtained by other methods.

 

2. The compositional characterization of MAX phase samples in recent articles need to be exhibited, which is favorable to understood and discerned.

Supplementary Table 1 contains compositional characterization of MAX phases in chronological order.

 

3. The chapter 2 of the manuscript, which is too verbose, conclusive tables of the relevant features are suggested.

Conclusive Table (Supplementary Table 1) was prepared and attached as a supplementary file.

 

4. In the manuscript, the writing of words and grammatical problems need to be corrected, such as the consecutive use of multiple identical prepositions and the contextualization of chemical formulas.

Corrected.

 

5. The correction on the order of reference is suggested. It is possible to reduce the number of references cited in the preceding text by inserting them sequentially in the following text.

Author prefers to leave references in the standard form.

 

6. The presentation of the letters on the figures are not standardized, and the spacing of the figures is not controlled. Harmonization of formats for the above issues is suggested.

Figure 1 was corrected. Other figures were presented by copyright permission from original manuscripts without modifying.

 

7. Some related works and form of writing may be helpful for this work, such as, Nano Research, 12, 471-487 (2019); Nano Research,15, 6551-6567 (2022); Adv. Energy Mater, 2023, 13, 2203903.

Thanks for the suggestion, however they link to MXenes which is out of scope for this article.

Reviewer 4 Report

This review summarizes the effectiveness of the self-propagating high-temperature synthesis method and presents the main findings regarding the optimization of combustion synthesis and its influence on microstructure features. It also discusses the impact of sample preparation, such as ball milling, preheating, and mechanical activation, as well as heating and cooling rates and ambient gas pressure on combustion parameters. However, the content and depth are not enough to be considered as the full review article. The author should either expand this paper’s contents or shorten it to be the communication type.

This review can be supplemented by the following aspects:

1.      How does SHS compare with other sintering techniques? What’s its unique advantage? Because other sintering techniques, i.e., pressureless sintering, spark plasma sintering, and HIP have been reported extensively and have their particular benefits compared to SHS. If SHS doesn’t surpass other sintering techniques in some unique areas, then why do we choose this technique?  

 

2.      Any applications of MAX phases which are made from the SHS technique? How do they differ from the counterpart made from other sintering techniques?

Minor editing of English language required.

Author Response

Review 4

This review summarizes the effectiveness of the self-propagating high-temperature synthesis method and presents the main findings regarding the optimization of combustion synthesis and its influence on microstructure features. It also discusses the impact of sample preparation, such as ball milling, preheating, and mechanical activation, as well as heating and cooling rates and ambient gas pressure on combustion parameters. However, the content and depth are not enough to be considered as the full review article. The author should either expand this paper’s contents or shorten it to be the communication type.

This review can be supplemented by the following aspects:

1. How does SHS compare with other sintering techniques? What’s its unique advantage? Because other sintering techniques, i.e., pressureless sintering, spark plasma sintering, and HIP have been reported extensively and have their particular benefits compared to SHS. If SHS doesn’t surpass other sintering techniques in some unique areas, then why do we choose this technique?  

I highly appreciate reviewer’s comments and recommendations. SHS is discussed here as a synthesis technique favorable against powder metallurgy in terms of energy-efficiency and availability of precursors. Thermal explosion under pressure or SHS combined with pseudo-HIP can lead to compact samples, which were presented in supplementary Table 1.

 

2. Any applications of MAX phases which are made from the SHS technique? How do they differ from the counterpart made from other sintering techniques?

Thank you for suggestion. A paragraph was added on page 17.

Round 2

Reviewer 4 Report

All previous answers are answered. Paper is good for publishing.