Microstructure and Mechanical Behavior of Hot Extruded Aluminum/Tin-Bismuth Composites Produced by Powder Metallurgy

Round 1

Reviewer 1 Report

Thanks for the manuscript.

The paper is well written. However, it might benefit the general readers if the material processing process is presented using real pictures, i.e.g, the process of extrusion.

Author Response

Response to Reviewer’s comments

The authors thank the editor and all the reviewers for investing their time and effort in evaluating our manuscript. We have addressed the comments provided by the reviewers. A detailed response to each comment is presented below. We hope that the revised manuscript will meet the publication quality of the journal.

Reviewer# 1

Comments to the Authors

Thanks for the manuscript.

The paper is well written. However, it might benefit the general readers if the material processing process is presented using real pictures, i.e.g, the process of extrusion.

Response to reviewer’s comments:

The authors would like to thank the reviewer for the encouragement and support for the publication. As suggested by the reviewer, we have added a schematic diagram representing the process of fabrication instead of a flow chart for the benefit of general readers.

Author Response File: Author Response.docx

Reviewer 2 Report

The research manuscript entitled “Microstructure and mechanical behavior of hot extruded Al-BiSn composites produced by powder metallurgy” is an original research paper describes the preparation and characterization of Al-BiSn composites using both microwave sintering and hot extrusion. Various analytical techniques were employed including XRD patterns and FESEM-EDX analysis. The properties of the prepared composites make them appropriate for various potential industrial applications. Thus, I recommend publication after minor revision pending the following comments:

- Remove abbreviations from title

- Keywords are too long, please revise.

- Abstract is too short and conclusion is just a repetition of abstract.

- Please define abbreviations in abstract (such as Al-BiSn and FESEM-EDX). For instance, field emission scanning electron microscopy associated with energy dispersive x-ray analysis (FESEM).

- Few grammatical mistakes should be corrected/revised.

Author Response

Response to Reviewer’s comments

The authors thank the editor and all the reviewers for investing their time and effort in evaluating our manuscript. We have addressed the comments provided by the reviewers. A detailed response to each comment is presented below. We hope that the revised manuscript will meet the publication quality of the journal.

Reviewer# 2

Comments to the Authors

The research manuscript entitled “Microstructure and mechanical behavior of hot extruded Al-BiSn composites produced by powder metallurgy” is an original research paper describes the preparation and characterization of Al-BiSn composites using both microwave sintering and hot extrusion. Various analytical techniques were employed including XRD patterns and FESEM-EDX analysis. The properties of the prepared composites make them appropriate for various potential industrial applications. Thus, I recommend publication after minor revision pending the following comments:

Response to reviewer’s comments:

We greatly appreciate the reviewer for reviewing our manuscript and providing very constructive comments. We sincerely hope that our responses will be up to the satisfaction of the reviewer.

Comment 1:

Remove abbreviations from title.

Response to Comment 1:

Thank you for this suggestion. We have removed the abbreviations from the title in the revised manuscript and modified the title to “Microstructure and mechanical behavior of hot extruded aluminum/tin-bismuth composites produced by powder metallurgy”

Comment 2:

Keywords are too long, please revise

Response to Comment 2:

As per the suggestion of the reviewer, keywords have been revised.

Keywords: Aluminum; tin-bismuth; composite; powder metallurgy; hot extrusion; mechanical properties.

Comment 3:

Abstract is too short and conclusion is just a repetition of abstract.

Response to Comment 3:

Thank you for pointing this out. Abstracts and the conclusions have been modified in the revised manuscript.

Comment 4:

Please define abbreviations in abstract (such as Al-BiSn and FESEM-EDX). For instance, field emission scanning electron microscopy associated with energy dispersive x-ray analysis (FESEM).

Response to Comment 4:

As per the suggestion, abbreviations have been defined in the abstract. Further, all the acronyms have been defined the first time they appear in the revised manuscript.

Comment 5:

Few grammatical mistakes should be corrected/revised.

Response to Comment 5:

Thank you for pointing this out. The whole manuscript has now been proof-read thoroughly for any grammatical and spelling mistakes.

Reviewer 3 Report

P2 L54-55: In the Introduction emphasize on the method used in this research should be given.  

P2 L64: Here I miss SEM /FESEM figures of both powders

P2 L65-71: Composite synthesis procedure by powder metallurgy is poorly described, while it is a crucial for final microstructure and properties;

- It is not clear how many samples of each composition were synthesized

- which atmosphere was used in the planetary ball mill

- state what the balls and the interior of the mill are made of

- specify cold compaction used; compaction pressure should be given in Pascals

- atmosphere in microwave sintering process should be given

- how the sintering temperature is determined?

P2 L71: Here I miss SEM /EDS figures of powder mixture after milling.

P2 L75: How the ratio 20.25:1 is determined?

P2 L82: Specify the metallographic preparation conditions.

P3 Figure 1 is too large and it is not necessary since the flow of the synthesis is described textually.

P3 L91-96: How many hardness measurements per sample were performed?

P4 L106: How the porosity is determined?

P4 Figure 2. the density and porosity markings are too similar so there is no clear difference in the black-white image

P5 L139: In the Fig4b there are no marks!

P6 It is not clear from the caption of Fig4 what the image b represents, so it should be written as: a)…. b).. .c) … d) EDX….

P7 In the caption for Fig 5 should be stated as: a)…b)..c)…d)…

P7 L214: instead of improvement should be stated increment because each increase does not mean improvement

P7 L215-216: Statement of increasing trend should be corroborated by additional FESEM figures

P8 L218: Densification has not been mentioned so far.  How is it obtained, how much is it?

P10 Table 1: How many tensile tests were performed per each sample?

P10 In the caption for Fig 8 should be stated as: a)…b)..c)…d)…

P11 L372: the statement: “The improved  mechanical  properties  are  attributed  to  the  secondary  processing..” is not appropriate since the results without secondary processing were not presented in this paper.

P12: References 4 and 24 were not given according to the Instructions for authors.

Author Response

Please see the attachment 

Author Response File: Author Response.pdf

Reviewer 4 Report

Review comments

The paper titled with “Microstructure and mechanical behavior of hot extruded Al-BiSn composites produced by powder metallurgy” investigated the structural, morphological, mechanical and thermal properties were investigated to elucidate the role of Bi60Sn40 (BiSn) alloy content (5, 10 and 15 wt.%) in modifying the properties of Al-BiSn composites. They found that hot extruded Al-15wt.% BiSn composite exhibits maximum hardness and tensile strength compared to pure Al. The results are interesting, but the manuscript in the current version cannot be accepted for publication. I recommend that this article be revised and reviewed again. Some comments as following:

1. 4, it is better to add the SEM images of Al-5BiSn and Al-10 BiSn.
2. 5, Fig. 8, what’s the difference in the images (a) to (d)? Some labels should be added to the figures.
3. Does the size and shape of BiSn particles affect the mechanical properties of Al-BiSn composite?
4. Why the addition of BiSn can improve mechanical properties? Some comprehensive discussions should be added.

Considering all the problems mentioned here above, some parts of this manuscript should be revised. I recommend that the manuscript should be revised.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Thank you for considering the major issues proposed in my review. I hope that you will agree with me that they contribute to the better understanding of manuscript.

Author Response

Responses to Reviewer 3

Comment 1

Thank you for considering the major issues proposed in my review. I hope that you will agree with me that they contribute to the better understanding of manuscript.

Response to Comment 1

The authors thank the reviewer for providing constructive comments which helped better the quality of the manuscript.

Reviewer 4 Report

The author revised the manuscript well based on the reviewer's comments, and I think it can be accepted for publication. 

Author Response

Responses to Reviewer 4

Comment 1

The author revised the manuscript well based on the reviewer's comments, and I think it can be accepted for publication. 

Response to Comment 1

The authors thank the reviewer for providing constructive comments which helped better the quality of the manuscript.