Effects of Graphite Particle Content and Holding Time on the Microstructure and Mechanical Properties of the Graphite/AZ91D Composite
, Jixue Zhou 1,*, Jianhua Wu 1, Xinfang Zhang 1,2 and Xitao Wang 1,2Round 1
Reviewer 1 Report
1. Change Fig. by Figure in the text.
Author Response
Response to Reviewer 1 Comments
Dear Editor and Dear Reviewers,
Thank you very much for the e-mail concerning our manuscript entitled “Effects of Cp content and holding time on the microstructure and mechanical properties of the Cp/AZ91D composite” and the attached reviewer’s comments. According to the comments from the reviewers, we have revised our manuscript. The following describes how the comments were addressed in the revised manuscript. The changes can be checked by revisions mode in the manuscript.
Declaration: In this study we used graphite particles (1-5μm) to investigate the effect of graphite particles (Gp) and holding time on the microstructure and mechanical properties of the Graphite/AZ91D composite. Some abbreviation may mislead the readers and the revisers, therefor we considerate to change some abbreviation.
Reviewer's comments:
Point 1: Change Fig. by Figure in the text.
Response 1: Thanks for your comments. In the revised manuscript, we have changed “Fig.” by “Figure”.
We hope the revised manuscript could meet the requirement for publication in Metals.
Your sincerely,
Xin Gao on behalf of all authors
Reviewer 2 Report
In this paper, the Effects of Cp content and holding time on the microstructure and mechanical properties of the Cp/AZ91D composite, are investigated which is of certain significance. It is recommended before accepting publication, consider the following recommendations:
1) More information and previous work on Cp/AZ91D composite need to be highlighted in the introduction.
2) Section 2 must be titled methodology and a flow chart illustrating the proposed method can improve the quality of the paper.
3) What are the Practical Applications of Cp/AZ91D composite?
4) A better abbreviation section for significance knowledge is required
5) Provide more data for sections 4.2 and 4.3.
6) Highlight the scientific benefit of this research.
7) The limitations of this research can be mentioned in the conclusions and also the future research.
8) Please correct the minor grammar errors throughout the manuscript
Author Response
Response to Reviewer 2 Comments
Dear Editor and Dear Reviewers,
Thank you very much for the e-mail concerning our manuscript entitled “Effects of Cp content and holding time on the microstructure and mechanical properties of the Cp/AZ91D composite” and the attached reviewer’s comments. According to the comments from the reviewers, we have revised our manuscript. The following describes how the comments were addressed in the revised manuscript. The changes can be checked by revisions mode in the manuscript.
Declaration: In this study we used graphite particles (1-5μm) to investigate the effect of graphite particles (Gp) and holding time on the microstructure and mechanical properties of the Graphite/AZ91D composite. Some abbreviation may mislead the readers and the revisers, therefor we considerate to change some abbreviation.
Reviewer's comments:
Point 1: More information and previous work on Cp/AZ91D composite need to be highlighted in the introduction.
Response 1: Thanks for your comment. We tried to modify the introduction and list more information and previous work on Graphite/AZ91D composite, e.g. reference [16, 17, 18], in the revised manuscript. The new reference list is also uploaded.
Point 2: Section 2 must be titled methodology and a flow chart illustrating the proposed method can improve the quality of the paper.
Response 2: Thanks for your comments. In the revised manuscript I have titled methodology as the Section 2’s title and have added a flow chart illustrating the proposed method too.
Point 3: What are the Practical Applications of Cp/AZ91D composite?
Response 3: Due to the low density, high specific strength and specific stiffness of the property of Graphite/AZ91D, Graphite/AZ91D are widely used in aerospace industry ( e.g. aircraft envelope et al.), automobile industries (e.g. shell of the car, the car seat et al.), military industry (e.g. outside shell of the missile ), and the outside shell of the mobile phone .
Point 4: A better abbreviation section for significance knowledge is required.
Response 4: Thanks for your comments. I have revised it in the manuscript.
Point 5: Provide more data for sections 4.2 and 4.3.
Response 5: Thanks for your comments. I tried to modified it so I have added some references [22,26] which could prove the feasibility of the formula and the theory.
Point 6: Highlight the scientific benefit of this research.
Response 6: Thanks for your comments. I have revised it in the manuscript.
Point 7: The limitations of this research can be mentioned in the conclusions and also the future research.
Response 7: Thanks for your comments. In the revised manuscript I have mentioned the limitation of the research and the outlook of the future research (Conclusions and outlooks point.4 ).
Point 8: Please correct the minor grammar errors throughout the manuscript.
Response 8: Thanks for your comments. In the revised manuscript I have corrected the minor grammar errors.
We hope the revised manuscript could meet the requirement for publication in Metals.
Your sincerely,
Xin Gao on behalf of all authors
Reviewer 3 Report
The objective of this article seems clear: the study of the influence of the addition of carbon on the hardness of the alloy based on Mg-Al. The results show that the hardness is significantly improved for an alloy with an addition of 1.5wt% C. However, the article does not meet the expected requirements for publication for the following reasons:
1- The authors correlate the evolution of the hardness to the presence of carbon or during the heat treatment the carbon must react with the Mg and Al to give the alloys Al4C3, MgC2... which can be responsible for this evolution. This makes the explanations given in this article very superficial
2- In relation to the first question, a detailed analysis of the particles by EPMA must be carried out to discriminate between the hypotheses of formation of Al4C3, MgC2.. or the presence only of carbon during the heat treatment.
See for example the reference: Materials 2019, 12, 2478; doi:10.3390/ma12152478
3- The diagrams of free enthalpy as a function of temperature (Fig 11) do not seem to correspond to those known in the literature (see review article Coltters (1985) Mater. Sci. Eng. 76. Moreover, reference 16 given in the manuscript is not complete and it does not give any free enthalpy diagram
4- Several passages of the manuscript, in particular those relating to the growth of the grains (lines 200-2016) and the velocity of the medium (264-279) seem to be taken from the literature without citation and do not have any real importance in the argument advanced
Other passages are without references (lines 46-48 for instance)
5- The references are not given with care: see for example above ref 16; references 19 and 23 are identical.
In addition, several references are incomplete (missing names of authors..)
6- The study by microscopy of the grain size remains too qualitative. Histograms are necessary for an accurate determination of grain size and size distribution (Fig 2)
7- The photos given in figure 3 are at the same magnification as those of figures 1 and 2 and yet the grains of the alloy are not seen here. Another question: on what basis are dark particles attributed to carbon?
8- If we want to study the influence of sintering time, we must keep the composition constant (C). However, this does not seem very clear in this work. Here we have the concomitant influence of two parameters (see table 1). What about?
9- what Cp does mean regarding the nomenclature of C phases (GNP, CNT..)
Author Response
Dear reviewer
Thank you very much for your carefully review. The attached file is the response.
Sincerely
Xin Gao
Author Response File: 
Author Response.pdf
Round 2
Reviewer 3 Report
The authors answered most questions. But two fundamental questions remain unanswered. The first concerns the nature of the particles observed (crabon or alloy of carbon with metals). The second corresponds to the Ellingham diagrams of the Al-C and Mg-C systems. indeed those given in the article do not conform to those of the literature (see article Coltters 1985). Also, Figure 14 contains errors: see x axis
Author Response
Dear revewer:
Thanks for your comments, I have revised the articles. The specific issues displayed on the attached file and the manuscript.
Sincerely
Xin Gao
Author Response File: Author Response.pdf
Round 3
Reviewer 3 Report
The paper is now acceptable.
Author Response
Dear reviewer
Thanks for your guidance which make the atticle more completely.
Yours.
Xin Gao
