Influence of High-Pressure Torsion Processing on the Tribological Properties of Aluminum Metal Matrix Composites
, Hossam Hemdan El-Fahhar 3, Abdelkarim Yousif Mohamed 3 and Elshafey Ahmed Gadallah 3
Round 1
Reviewer 1 Report
The paper entitled; "Influence of the Powder Metallurgy and the High-Pressure Torsion Processing on the Tribological Properties of Aluminum Metal MatrixComposites" is an interesting article that contains exciting experimental results. I think this manuscript can be improved. Therefore, it can be accepted in your valuable journal after the following comments have been considered by the authors:
1. In my opinion, the title of the article is not appropriate, moreover, there should be a space between some words (MatrixComposites).
2. The introduction is well and comprehensively written, but the authors should refer to many modern references, such as
https://doi.org/10.1007/s12633-021-01641-z,
https://doi.org/10.1016/j.wear.2022.204511,
rather than older references, in describing microstructure and wear properties in composite materials.
4. The authors did not mention the novelty of their work. Thus, the novelty of this work should be clearly discussed.
5. Important points on SEM images should be marked with an arrow.
6. Unnamed peaks are seen in EDS analyzes (e.g. Figures 11-12e-f, Figures 16a-d). This situation should be discussed in detail.
Author Response
AUTHOR REPLY TO THE REVEIWER COMMENTS ON materials-2083274
Dear the editor,
Thank you for conveying to me the recommendations of the referee.
We revised our manuscript altered in line with the suggestions of reviewer 1. We want to respond to his comments as follows.
Answer to the Reviewer#1
Title
(1) In my opinion, the title of the article is not appropriate, moreover, there should be a space between some words (MatrixComposites).
Answer: The title changed to "Influence of the High-Pressure Torsion Processing on the Tribological Properties of Aluminum Metal Matrix Composites" Page no 1, and Lines 2-4.
The authors confirm a space between the words (MatrixComposites); maybe the difference in the Word program versions is the reason for that.
Introduction
(1) The introduction is well and comprehensively written, but the authors should refer to many modern references, such as
https://doi.org/10.1007/s12633-021-01641-z,
https://doi.org/10.1016/j.wear.2022.204511,rather than older references, in describing microstructure and wear properties in composite materials.
Answer: The authors added the two suggested manuscripts in the introduction, related them to the PM method's improvement, and numbered them as references [6 & 7]. Pages no 1 and 2, and Lines 44-50.
The old references describing microstructure and wear properties in composite materials were already used through references from 26-30 in the old version. References from 26-30 in the old version are 29-33 in the current version.
(2) The authors did not mention the novelty of their work. Thus, the novelty of this work should be clearly discussed.
Answer: The novelty of their work was clarified as following" Unfortunately, no previous studies cover the influence of the HPT on the wear scars, wear resistance, and friction properties of the Al MMCs. Moreover, there was a shortage in the correlation between the wear rate and friction properties from one side and the worn surface morphology. Therefore, a comprehensive study of the effect of HPT on different Al MMCs tribological characteristics is still required." Page no 5, Paragraph no 5, and Lines 73-82.
Results and Discussion
(1) Important points on SEM images should be marked with an arrow.
Answer: The important points on SEM images were marked with arrows (figures 7, 9, and 13-15). Moreover, the arrows' colors and what it refers to were added to the manuscript text. Lines 250, 270-271, 369 and 377.
(2) Unnamed peaks are seen in EDS analyzes (e.g. Figures 11-12e-f, Figures 16a-d). This situation should be discussed in detail.
Answer: The unnamed peaks were named, and the peaks were all related to tungsten W.
We appreciate the reviewer's and editor kind and instructive comments and hope that the revisions are satisfactory and that the revised version of the paper will be acceptable for publication in materials
Yours sincerely,
The authors
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Ref.: Ms. No. materials-2083274-peer-review-v1
Manuscript entitled: Influence of the Powder Metallurgy and the High-Pressure Torsion Processing on the Tribological Properties of Aluminum Metal MatrixComposites
Recommendation: Major revisions
Comments:
In order to enhance the mechanical properties and wear resistance of Al alloys, the authors focus on the topical issues Al MMCs and high-pressure torsion (HPT) process, which is fundamentally interesting.
This article has a complete structure and relatively clear logic, which is suggested to be published, but the following questions must be answered and the major revisions must be implemented.
1. There are too many long sentences in this manuscript, and the expression of each sentence is not clear enough, which needs to be carefully revised.
2. There are many methods to prepare MMC, such as rapid solidification, additive manufacturing, casting, PM, etc, why do the authors choose PM to fabricate the Al and its MMC?
3. There are many SPD processing methods, such as forging, ECAP, rolling, HPT, etc, why the authors choose the HPT method? What are its unique advantages?
4. There are many grammatical errors in the manuscript, such as: “The fabrication of different Al MMCs enhances the Al hardness and wear resistance obviously over those of the Al pure samples [26-30].”. It is recommended to polish the grammar carefully.
5. The authors did not describe the microstructural transformation of Al alloys before and after the addition of reinforcements or HPT treatment. It is well known that the transformation of the microstructure determines the mechanical and tribological properties of Al alloys.It is suggested to supplement the section of microstructure analysis.
6. There are many kinds of additives for PM Al MMCs, including various types of oxides, nitrides, carbides and other reinforcing phases. This paper only analyzes the effects of Al2O3 and SiC addition on the mechanical and tribological properties of Al alloys. It is suggested that the authors should analyze the influence of other additives on the mechanical and wear performances of Al alloy, and find out the common characteristics, so as to provide scientific reference for the following research work.
7. Both MMC preparation and HPT treatment can enhance the mechanical and tribological performances of Al alloys, but their strengthening mechanisms are different. It is suggested that these two processes will be described and analyzed in different sections to make it easier for readers to understand.
Author Response
AUTHOR REPLY TO THE REVEIWER COMMENTS ON materials-2083274
Dear the editor,
Thank you for conveying to me the recommendations of the referee.
We revised our manuscript altered in line with the suggestions of reviewer 2. We want to respond to his comments as follows.
Answer to the Reviewer#2
English Language
(1) There are too many long sentences in this manuscript, and the expression of each sentence is not clear enough, which needs to be carefully revised.
(4) There are many grammatical errors in the manuscript, such as: “The fabrication of different Al MMCs enhances the Al hardness and wear resistance obviously over those of the Al pure samples [26-30].”. It is recommended to polish the grammar carefully.
Answer: The English language was checked carefully throughout the manuscript by an English native.
Introduction
(2) There are many methods to prepare MMC, such as rapid solidification, additive manufacturing, casting, PM, etc, why do the authors choose PM to fabricate the Al and its MMC?
Answer: The advantages of selecting PM over other MMCs fabrication methods were added." Moreover, the PM can produce ultrafine fine (UF) and nanostructure MMCs. The PM of UF and nano powders and the combination between PM and mechanical alloying such as ball milling, can effectively produce UF and nanostructure MMCs [6, 7]. Furthermore, the low sintering temperature used in PM can conserve the UF and nano microstructure relative to the higher temperature used in other methods, such as rapid solidification and different casting methods. Using the PM can also be considerably cheaper than the modern method in the fabrication MMCs, such as additive manufacturing." Pages no 1and 2, and Lines 44-50.
(3) There are many SPD processing methods, such as forging, ECAP, rolling, HPT, etc, why the authors choose the HPT method? What are its unique advantages?
Answer: The advantages of selecting HPT over other SPD methods were clarified and added." Although, the HPT suffers from limits for the upscaling and relatively lower deformation homogeneity as it inherent radius dependence of the strain. However, the HPT has different advantages over the other SPD processes, such as permitting a defined continuous variation of strain where most SPD processes offer only a stepwise application of strain. Moreover, HPT imposes high shear, so HPT can effectively process brittle or high-strength materials such as MMCs, which is often impossible by other SPD processes. Further advantages of the HPT process can be found in detail in previous work [25]." Page no 2, Paragraph no 3, and Lines 58-64.
Materials and Methods
(6) There are many kinds of additives for PM Al MMCs, including various types of oxides, nitrides, carbides and other reinforcing phases. This paper only analyzes the effects of Al2O3 and SiC addition on the mechanical and tribological properties of Al alloys. It is suggested that the authors should analyze the influence of other additives on the mechanical and wear performances of Al alloy, and find out the common characteristics, so as to provide scientific reference for the following research work.
Answer: The selection of the Al2O3 and SiC in the current study relative to other different ceramics was based on different reasons.
- Al2O3 and SiC are the most popular and cheapest ceramics. Therefore, Al2O3 and SiC can be used commercially for the mass production of MMCs.
- The high mechanical properties of both Al2O3 and SiC obviously improve the mechanical properties of the MMCs.
- Al2O3 and SiC both have a low degree of chemical reaction with the Al matrix, so high bonding can be obtained.
- Using previous work of Al MMCs reinforced with other ceramics; how to use these manuscripts in comparison with current study results and analysis of the current results relative to the previous one.
- Adding more information about those topics will increase the similarity in the manuscript.
Results and Discussion
(5) The authors did not describe the microstructural transformation of Al alloys before and after the addition of reinforcements or HPT treatment. It is well known that the transformation of the microstructure determines the mechanical and tribological properties of Al alloys. It is suggested to supplement the section of microstructure analysis.
Answer: The authors would like to thank the reviewer for this suggestion. However, the microstructure observations fully cover in the authors' previous work published in materials (Materials 2022, 15(24), 8827) (named as reference 23 in the previous version, which is named now reference 26). The microstructure observations were performed and fully covered using different microscopes, including OP, SEM, and TEM. So, adding the microstructure part will be redundant work for the manuscript and will increase the similarity percentage.
Please see the materials and methods section. pages no2 and 3, and lines 92-99.
(7) Both MMC preparation and HPT treatment can enhance the mechanical and tribological performances of Al alloys, but their strengthening mechanisms are different. It is suggested that these two processes will be described and analyzed in different sections to make it easier for readers to understand.
Answer: The authors would like to indicate their profound thanks to the reviewer for this suggestion. However, this suggestion was fully covered in the authors' previous work published in materials (Materials 2022, 15(24), 8827) (named as reference 23 in the previous version, which is named now reference 26). Furthermore, the strengthening mechanisms of both PM and HPT of MMCs and even the calculation of the strength theoretically and the confirmation of this experimentally were also covered in the corresponding author's previous work (named as reference 16 in the previous version, which is named now reference 18). Therefore, adding a strengthening part will be redundant work for the manuscript and increase the similarity percentage.
A hint was add to the readers to guide them for the reference related to strengthening mechanisms of both PM and HPT of MMCs and so increase of hardness. Page no 4, and lines 140-141.
We appreciate the reviewer's and editor kind and instructive comments and hope that the revisions are satisfactory and that the revised version of the paper will be acceptable for publication in materials.
Yours sincerely,
The authors
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
All recommended changes in the revised manuscript have been made correctly. Therefore, the article can be accepted for publication.
