From Bauxite as a Critical Material to the Required Properties of Cast Aluminum Alloys for Use in Electro Automotive Parts
Round 1
Reviewer 1 Report
This paper addresses the critical aspects of cast aluminum alloys in the context of electro-automotive components and the casting processes suitable for them. However, I would like to express some concerns regarding its scientific significance and certain issues that need attention:
1. The paper appears to lean more towards a popular science style, potentially lacking the depth of scientific discourse expected in academic publications.
2. There seems to be a reliance on images that are directly sourced from references, which might require further processing to enhance readability and maintain consistency in image quality.
3. The tables within the paper exhibit inconsistencies in quality, with Table 3 standing out as an example that appears to have been handled less meticulously.
4. It is essential to verify that proper authorization and permissions have been obtained for the inclusion of figures and tables from external sources to adhere to copyright and ethical publication standards.
Overall, while the paper presents valuable information, it may benefit from improvements in these areas to align with the publication standards typically expected in academic journals.
Moderate editing of English language required.
Author Response
Review of Manuscript ID metals-2639889
Comments and Suggestions for Authors
This paper addresses the critical aspects of cast aluminum alloys in the context of electro-automotive components and the casting processes suitable for them. However, I would like to express some concerns regarding its scientific significance and certain issues that need attention:
Response: The authors are grateful to the Reviewer for spending the time to carefully analyze and comment on the results presented and discussed in the manuscript, and useful suggestions they made.
Q1. The paper appears to lean more towards a popular science style, potentially lacking the depth of scientific discourse expected in academic publications.
Response 1: The main concern in this paper was to give an overview what types of alloys, casting processes and heat treatment can be applied for the production in aluminum casting plants to fulfill the required mechanical and thermophysical properties of electro automotive parts and to highlight some new specific properties such as dimensional stability, corrosion resistance, electromagnetic compatibility, crashworthiness which cast parts need to satisfy to be applied in the e-vehicles. Our main intention in this paper was to indicate that in this moment in the available world aluminum market suitable alloys for production of e mobility parts can be find and use without any restrictions. In other words we would like to bring a message to aluminum casting community that there is no need for development of a new alloys. For such alloys there are appropriate casting and heat treatment processes which can be applied in production of e mobility parts without any changes.
Q2. There seems to be a reliance on images that are directly sourced from references, which might require further processing to enhance readability and maintain consistency in image quality.
Response 2: Thank you for the comment. Images quality is improved.
Q3. The tables within the paper exhibit inconsistencies in quality, with Table 3 standing out as an example that appears to have been handled less meticulously.
Response 3: In the available literature there are many papers which deals with the impact of alloying elements on the corresponding mechanical and thermophysical properties of cast Al alloys. Our intention regarding Table 3 was to indicate readers where to find information regarding impact of each alloying element on mechanical properties, not to discuss its impact in detail. As it was mentioned in the answer to first question, our main intention was to bring attention to new properties needed for e mobility parts.
Q4. It is essential to verify that proper authorization and permissions have been obtained for the inclusion of figures and tables from external sources to adhere to copyright and ethical publication standards.
Response 4: We got the copyright permissions for all needed and from Editor requested Figures and Tables.
Q5. Overall, while the paper presents valuable information, it may benefit from improvements in these areas to align with the publication standards typically expected in academic journals.
Response 5: Thank you for valuable comments and useful suggestions.
Q6. Comments on the Quality of English Language
Moderate editing of English language required.
Response 6: Thank you, we have improved the English language in the paper.
Reviewer 2 Report
Abstract part needs to be improved i.e, Novality of the work to be reframed, and it should align with conclusion part.
At the same time conclusion part is too much long, it is very difficult to get the detailed invention of the manuscript. It should be reduced to point wise conclusion.
Introduction part is lagging with present trend of the work done, it needs to be improved by adding some more literature.
Author briefly summerizes the heat treatment techniques for aluminium alloys (T6, T5), it should be explained clearly.
Manuscript should be throughly checked for continous sentances.
Quality of all the figures should be improved.
Gramatical corrections to be checked throughly.
Author Response
- Review Report Form - RESPONSE
Review of Manuscript ID metals-2639889
Response: The authors are grateful to the Reviewer for spending the time to carefully analyze and comment on the results presented and discussed in the manuscript, and especially for useful suggestions they made.
All suggested corrections are included in the manuscript.
Comments and Suggestions for Authors
Q1. Abstract part needs to be improved i.e, Novelty of the work to be reframed, and it should align with conclusion part.
Response 1: Thank you. Here is the new version, already included in the text.
New version:
Abstract: There is a long way from bauxite, as a critical raw material, to the required properties of cast aluminum alloys for electroautomotive parts. Thanks to its unique properties, aluminum has become the material of choice for clean technology manufacturers in applications such as automotive industry, renewable energy, batteries, electrical systems, resource saving packaging, energy efficient buildings, and clean mobility. Restructuring of the economy, the oil crisis, air pollution and global warming are some of factors that moved automotive industry towards electrification at the beginning of the 21st century. This paper aims to highlight the required properties of cast aluminum alloys applied to the production of electroautomotive parts such as mechanical and thermo-physical properties, dimensional stability, corrosion resistance, electromagnetic compatibility, and crashworthiness. Furthermore, this paper discusses which of the cast aluminum-silicon alloys as well as the heat treatment and casting processes are most suitable to produce electroautomotive parts.
Q2. At the same time conclusion part is too much long, it is very difficult to get the detailed invention of the manuscript. It should be reduced to point wise conclusion.
Response 2: Thank you. Here is the new version, already included in the text.
New version;
- Conclusions
Cast aluminum alloys are extremely attractive for production of electro automotive parts due to their respectable properties such as: good mechanical and thermophysical properties, great dimensional stability, acceptable corrosion resistance, known electromagnetic compatibility, and predictable crashworthiness. It means that this market will need more aluminum in the future. There are several cast aluminum alloys: (EN AC – 47000 (AlSi12(Cu1), EN AC – 44300 (AlSi12(Fe), EN AC – 43500 (AlSi10MnMg), EN AC – 42100 (AlSi7Mg) available in the world market, that can be used for mass production of electro automotive parts applying following casting processes: HPDC, LPDC and CPS. The mechanical properties of these alloys can be further improved through suitable heat treatment processes (T5, T6 and T7) and additional alloying with major and minor alloying elements. The main concern with the addition of alloying elements to existing aluminum alloys should be considered in terms of their limited content and effect on the corrosion of the cast parts. Moreover, the cost of some alloying elements may be potentially the limiting factor for their use in the production of electroautomotive parts.
Q3. Introduction part is lagging with present trend of the work done, it needs to be improved by adding some more literature.
Response 3: Thank you. We have added more references published in recent 3 years (2020-2023).
- Czerwinski, F. Current Trends in Automotive Lightweighting Strategies and Materials. Materials 2021, 14(21), 6631. https://doi.org/10.3390/ma14216631
- Steglich, J.; Luisa Marzoli, L.; Zerbin, I. Cast alloys for electric vehicle powertrains. In Proceedings of the European Aluminium Conference by GDA TRIMET Aluminium SE, EAC Düsseldorf, November 25-26, 2019, DOI:10.13140/RG.2.2.27047.78245, pp. 1-18.
- Kim, S.-W.; Lee, S.-J.; Kim, D.-U.; Kim, M.-S. Experimental Investigation on Tensile Properties and Yield Strength Modeling of T5 Heat-Treated Counter Pressure Cast A356 Aluminum Alloys. Metals 2021, 11, 1192. doi: 10.3390/met11081192.
- Kim, D.; Maeng, H.; Choi, Y.; Choi, H.; Lee, S.J. Constitutive Model of Triple-Step-Aged Al–Mg–Si Alloy Incorporating Precipitation Kinetics. Met. Mater. Int. 2021, 27 (11) 4577–4585.
- Mao, H.; Bai, X.; Song, F.; Song, Y.; Jia, Z.; Xu, H.; Wang, Y. Effect of Cd on Mechanical Properties of Al-Si-Cu-Mg Alloys under Different Multi-Stage Solution Heat Treatment. Materials 2022, 15, 5101. https://doi.org/10.3390/ma15155101
- Choi, S.; Jeon, J.; Seo, N.; Son, S.B.; Lee, S.J. Effect of Heating Rate on Microstructure and Mechanical Properties in Al 7055. Met. Mater. Int. 2021, 27, 449–455.
- Patarić, A.; Mihailović, M.; Marković, B.; Sokić, M.; Radovanović, A.; Jordović, B. Microstructure as an essential aspect of 7075 aluminum alloy quality influenced by electromagnetic field during continual casting process. Chemical Industry 2021, 75(1), 31-37. https://doi.org/10.2298/HEMIND201214006P
- Wang, Z.; Fu, B.; Wang, Y.; Dong, T.; Li, J.; Li, G.; Zhao, X.; Liu, J.; Zhang, G. Effect of Cu Content on the Precipitation Behaviors, Mechanical and Corrosion Properties of As-Cast Ti-Cu Alloys. Materials 2022, 15, 1696. doi: 10.3390/ma15051696
- Wang, Z.; Dong, L.; Hu, B.; Chen, B. The effect of Cu addition on corrosion resistance of Al-Si-Mg-Cr alloy. Metals, 2023, 13(4), 759, 1-13. https://doi.org/10.3390/met13040795
Q4. Author briefly summerizes the heat treatment techniques for aluminium alloys (T6, T5), it should be explained clearly.
Response 4: This text is added at line 140 (immediately after subtitle # 4):
Cast aluminum alloys are lightweight structural materials that can be strengthened through alloying. Additionally, some of aluminum alloys which contain Cu, Mg and Zn can be further strengthened by heat treatment. The heat treatment of aluminum castings is carried out to change the properties of the as cast alloys by subjecting the casting to a thermal cycle or series of thermal cycles. The conditions of thermal treatment of castings as defined by EN 1706 [8] are as follows: F – as cast, T1- controlled cooling from casting and naturally aged, T4 -solution heat treated and naturally aged, T5 – Controlled cooling from casting and artificially aged or over aged, T6 – Solution heat treated, quenched (water or air) and artificially aged and T7 – Solution heat treated, quenched (water or air) and over aged (stabilized)
Q5. Manuscript should be throughly checked for continous sentances.
Response 5: All the sentences are thoroughly checked. Thank you.
Q6. Quality of all the figures should be improved.
Response 6: Thank you for the comment. Images quality is improved.
Q7. Comments on the Quality of English Language
Grammatical corrections to be checked throughly.
Response 7: English language spelling, as well as grammatical mistakes are thoroughly checked. Thank you.
Reviewer 3 Report
The paper is a review considering aluminum as a raw material for economy and a discussion concerning the cast aluminum-silicon alloys as well as the heat treatment and casting processes for the most suitable for the production of electro automotive parts.
Some correction must be made:
1. Please insert in the table 1 the entire name of the casting process, for a better understanding of the data.
2. In the table 2 there are given some aluminum allozs in according with DIN 1706 [8]. Generally, these mechanical properties are given in a range of values. Why the authors put fixed values for mechanical properties?
3. Put in figure 2 [MPa], instead [Mpa].
4. Try to improve the quality of figures 3,4,5!
5. Put the name of a horizontal axis “zeit” as “time” in figure 5.
6. Try to enlarge the text in figure 6, there is no visibility in axis.
7. Put “Conclusions” instead of “Conclusion” on the 10th part of the paper.
8. Put in template the authors in References.
9. There are many uncompleted data in the references, for example reference 1, reference 5, reference 12 and put all the authors in references: 13,14 15, 18, 20, 21, 22, 26, 27, 28.
Comments for author File: 
Comments.pdf
Author Response
- Review Report Form - RESPONSE
Review of Manuscript ID metals-2639889
Comments and Suggestions for Authors
The paper is a review considering aluminum as a raw material for economy and a discussion concerning the cast aluminum-silicon alloys as well as the heat treatment and casting processes for the most suitable for the production of electro automotive parts.
Response: The authors are grateful to the Reviewer for spending the time to carefully analyze and comment on the results presented and discussed in the manuscript, and useful suggestions they made.
Some correction must be made:
Q1. Please insert in the table 1 the entire name of the casting process, for a better understanding of the data.
Response 1: The full name of the casting processes is inserted in each cell of the Table 1. However, please note that the full name has already been mentioned the text, next to the abbreviation, and we are not sure that the table should contain it.
Q2. In the table 2 there are given some aluminum alloys in according with DIN 1706 [8]. Generally, these mechanical properties are given in a range of values. Why the authors put fixed values for mechanical properties?
Response 2: Attached There are given single values for mechanical properties in the EN standard, based on DIN 1706 (please see one example from EN 1706 beneath).
Q3. Put in figure 2 [MPa], instead [Mpa].
Response 3: Thank you. This is corrected.
Q4. Try to improve the quality of figures 3,4,5!
Response 4: Thank you. Images quality is improved.
Q5. Put the name of a horizontal axis “zeit” as “time” in figure 5.
Response 5: Thank you. This is corrected.
Q6. Try to enlarge the text in figure 6, there is no visibility in axis.
Response 6: Thank you. This is corrected.
Q7. Put “Conclusions” instead of “Conclusion” on the 10th part of the paper.
Response 7: Thank you. This is corrected.
Q8. Put in template the authors in References.
Response 8: Thank you. This is corrected.
Q9. There are many uncompleted data in the references, for example reference 1, reference 5, reference 12 and put all the authors in references: 13,14 15, 18, 20, 21, 22, 26, 27, 28.
Response 9: Thank you. This is corrected.
Author Response File: Author Response.pdf
Reviewer 4 Report
This work summarized the applications of cast aluminum alloy in automotive industries with required properties, including the type and heat treatment. The information is useful for the selection of proper cast aluminum alloys for industries. However, there are some few points to be clarified as below:
1. It seems only Al-Si cast alloys are widely discussed in this paper. In the industrial applications, Al-Cu cast alloys are also widely used for auto parts, which is suggested to included.
2. Fatigue resistance is one of significant safety concerns for the application of Al cast alloys in auto industries, which should be also discussed.
3. For the casting process, semi-solid formation (SSF) is also widely used to fabricate the auto parts. Then it may suggest including in the discussion.
N/A
Author Response
- Review Report Form - RESPONSE
Review of Manuscript ID metals-2639889
This work summarized the applications of cast aluminum alloy in automotive industries with required properties, including the type and heat treatment. The information is useful for the selection of proper cast aluminum alloys for industries. However, there are some few points to be clarified as below:
Response: The authors are grateful to the Reviewer for spending the time to carefully analyze and comment on the results presented and discussed in the manuscript, and useful suggestions they made.
Q1. It seems only Al-Si cast alloys are widely discussed in this paper. In the industrial applications, Al-Cu cast alloys are also widely used for auto parts, which is suggested to included.
Response 1: More than 90 % of cast parts used in automotive industry have been produced using Al - Si alloys. Aluminum alloys based on Si as major alloying elements will be also used for production of e-mobility parts. E-mobility parts, due to the high request for the corrosion resistance, are allowing application of aluminum alloys with very low content of copper (some OEM request <0.1Cu wt.%). Therefore, we did not consider this type of aluminum alloys in our paper.
Q2. Fatigue resistance is one of significant safety concerns for the application of Al cast alloys in auto industries, which should be also discussed.
Response 2: We fully agree with previous comments that for the engine parts (cylinder heads, motor block end so on) fatigue resistance is very important property. However, for e-mobility parts some other properties such as dimensional stability, corrosion resistance, electromagnetic compatibility, and crashworthiness are more important, and therefore have been discussed in our paper.
Q3. For the casting process, semi-solid formation (SSF) is also widely used to fabricate the auto parts. Then it may suggest including in the discussion.
Response 3: Searching through the available literature we did not find that SSF process is considered at least by major OEM producers as an alternative process for production of e-mobility parts. Many of the OEM experts proposed HPDC and LPDC as more suitable processes for serial production of e mobility parts.
Round 2
Reviewer 1 Report
Thank you for the author's revisions. I have one more suggestion for improvement: please further enhance Table 3. The current version of Table 3 is not visually appealing and is affecting its readability.
Minor editing of English language required.
Author Response
Dear Reviewer,
thank you very much for your invested time and valuable comments. According to your comment we improved our text:
"I have one more suggestion for improvement: please further enhance Table 3. The current version of Table 3 is not visually appealing and is affecting its readability."
Now We increased Font Size in order to increase its readability! Now we are sure that this table is sutable for a reading.
Reviewer 4 Report
The paper is suggested to be accepted.
N/A
Author Response
Dear Reviewer,
thank you very much for you invested time and valuable comments, that helped us to improve our paper!
Best regards
Srecko
