The Effect of Annealing on the Microstructure and Properties of Ultralow-Temperature Rolled Mg–2Y–0.6Nd–0.6Zr Alloy
Round 1
Reviewer 1 Report
This article is a very good scientific work, written in a competent scientific language, the research methods are described in detail, all stages of the study are clearly illustrated and confirmed by conclusions.
as a side note:
1) I did not understand the dimensions of the test piece
2) what is the density of the resulting alloy?
3) what is the field of application of the obtained alloy, how comparable is it with analogues?
4) in Figure 11 I would like to see the confidence interval
5) how did you manage to achieve such an accuracy of Ultimate tensile strength / Elongation measurements in Table 1? what deviation in the results obtained is significant?
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
The reviewer comments of the paper «The effect of annealing on the microstructure and properties of ultra-low-temperature-rolled Mg-2 Y-0.6 Nd-0.6 Zr alloy»
- Reviewer
The authors presented an article «The effect of annealing on the microstructure and properties of ultra-low-temperature-rolled Mg-2 Y-0.6 Nd-0.6 Zr alloy». In general, the article is interesting and written at a good scientific level. However, there are several points in the article that require further explanation.
Comment 1:
The introduction needs to be improved.
Show more clearly the relevance of the magnesium alloy under study. Prospects for its application. In terms of relevance, add an article: DOI: 10.3390/ma11050808. What difficulties exist now and what you will decide in the article. Show white spots clearly. Thanks to the analysis, it is necessary to clearly show what has been done earlier and what needs to be solved in this study. This way you can clearly define Group citations in a single phrase should be avoided: [1-4]; [19-25]. This does not provide a more detailed understanding of the reader about the contribution of each article. Try to at least break this sentence into several parts: ... [?], ... [?], ... [?]. Or give a more detailed analysis of each reference.
It is also helpful to add a paragraph on the main ECAP advances to improve the properties of magnesium alloys.
At the end of the introduction, state a clear and understandable purpose of the article. Also provide a brief description of what has been done in each section of the article.
Comment 2:
- Materials and methods
Figures should be placed immediately after a mention in a paragraph of text. For example, figure 1 needs to be placed on the paragraph above. Check it out throughout the article.
Comment 3:
It will be useful to add a section of Nomenclature in which to sign all the physical quantities and abbreviations encountered in the article. There are many physical quantities in the text and such a section will help to find the description of the necessary element.
For example,
ECAP : Equal channel angular pressing
etc.
Comment 4:
Conclusions.
In addition, it is necessary to more clearly show the novelty of the article and the advantages of the proposed method. What is the difference from previous work in this area? Show practical relevance. Conclusions should reflect the purpose of the article.
Comment 5:
References
It must be issued in accordance with the MDPI requirements.
The article is interesting and written at a good scientific level. Authors should carefully study the comments and make improvements to the article step by step. After major changes can an article be considered for publication in the "Metals".
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
The present manuscript investigated the effect of the cryogenic rolling on the microstructure leading to the tensile properties. The topic is very interesting and valuable for the application of Mg alloys. However, the authors need to clarify the following issues.
- Extensive English editing needs to be done. For an example: “…the ……” it can be “the twin disappears, and more uniform equiaxed grains are formed.”…
- The abstract needs to be re-written. I lost in one sentence. “the twins formed were mainly …...”. Is it formed during rolling or annealing, really confusing? Please deliver a clear message.
- There are some interesting papers published on the same topics. The author needs to add them for a comprehensive literature review.
- De-twinning and texture change in an extruded AM30 magnesium alloy during compression, Journal of Materials Science and Technology, 31, 2015, pp. 264-268.
- Twin growth and texture characteristics in an extruded AM30 magnesium alloy during compression, Journal of Materials Science and Technology, 30, 2014, pp. 884-887.
- Influence of pre-deformation and subsequent annealing on strain hardening and anisotropy of AM30 magnesium alloy, Journal of Alloys and Compounds, 611, 2014, pp. 341-350.
- The orientation dependence of strain hardening and texture development in an extruded magnesium alloy, Materials Science Forum, 783-786, 2014, pp. 363-368.
- Influence of pre-strain on de-twinning activity in an extruded AM30 magnesium alloy, Materials Science and Engineering A, 605, 2014, pp. 73-79.
- Dependence of compressive deformation on pre-strain and loading direction in an extruded magnesium alloy: Texture, twinning and de-twinning, Materials Science and Engineering A, 596, 2014, pp. 134-144.
- Texture transformation in an extruded magnesium alloy under pressure, Materials Science and Engineering A, 582, 2013, pp. 63-67.
- De-twinning and strain hardening of an extruded magnesium alloy during compression, Scripta Materialia, 67(2), 2012, pp. 165-168.
- A comprehensive experimental detail is required to replicate the data. The materials processing was explained nicely. However, please describe following the experiment in detail.
- What was the ASTM standard to conduct the tensile test?
- How the samples were extracted and prepared for microstructural analysis especially for TEM and EBSD?
- EBSD: what were the experimental parameters used for this analysis such as confidence index, step size, data cleaning, etc.?
- TEM: TEM sample preparation is a crucial factor to obtain the proper analysis. Please add the sample preparation in detail. To obtain accurate dislocation density, the sample must be free from any mechanical deformation. Ion polishing will artificially generate dislocations leading to twining in Mg alloys. So, electro-polishing is recommended for this kind of analysis.
- Author claim that cryogenic rolling followed by annealing significantly improves ductility. However, the room rolling at a high strain rate also shows the same behavior. Why industries will adopt this idea as it will increase the tooling cost significantly. So, the author should provide a comparative reason why this study better than the others.
- If the claim of this paper is valid. What is the mechanism to improve the ductility? The grain size is not ultra-fine. Still, twinning can occur during deformation especially during compression.
- The compression deformation is the problem in Mg alloy. What is the compression fracture strain after this treatment?
- Please focus on your results and provide solid evidence for the claim.
- The conclusion is too long. Please make them concise and short.
- Please check the references carefully.
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The authors have improved the article according to the comments. However, before publishing, correct for adequate names in the reference [1]. After that, the article can be accepted for publication.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Please incorporate all the recommended information in the manuscript, not in the response letter.
To get good and shiny surfaces of the TEM sample, two things need to be considered. (I) proper electrolyte and (ii) accurate process parameters like flow rate, voltage, and current.
Please add a note in Fig. captions "there could be the possible formation of an artificial generation of dislocation during ion milling".
or you may replace the TEM images that show the dislocation, with geomatical necessity dislocation (GND) plot images calculated using EBSD.
Author Response
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Author Response File: Author Response.pdf
