Research Progress on Mechanical Behavior of Closed-Cell Al Foams Influenced by Different TiH2 and SiC Additions and Correlation Porosity-Mechanical Properties
Round 1
Reviewer 1 Report
The manuscript entitled "Research progress on mechanical behavior of closed-cell Al foams and correlation porosity-mechanical properties". In my opinion, this review is interesting and has a certain reference in the development for the application in the fields of lightweight materials. However, there are some remarks that should be taken into consideration by the authors in order to raise this article to a good level for publication in Applied Sciences.
The suggested modifications are listed as follows:
1. Acronyms that first appear should be explained in detail. Such as: MTS.
2. Figure 3- Figure 6 can be combined into one large image. The 2 (TiH2) of Figure 6 should be the subscript.
3. All graphs and tables should cite references if they come from literature.
4. The sequence numbers of many graphs are out of order.
5. Through the review, can the author offer some guiding opinions for future research?
Author Response
Please see attached file
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The paper studies closed-cell Al foams with different compositions in TiH2 and SiC. Compressive tests have been done to correlate the microstructure – property relationship (porosity). Samples with SiC = 2.8% and TiH2 = 0.4% have the highest energy absorption while samples containing SiC = 6% and TiH2 = 0.2% show good overall foam properties. The paper is written well, but the structure is not good. One can see the confidence in conducting this study, but the motivation or rather the scientific knowledge gain is not clear. Please make clearer what the gained knowledge is! There is no real discussion of the results, which is the core essential of a scientific paper. That is, unfortunately, the mail lack of this paper. See following further comments:
Title:
- it would be wise to provide the composition or rather what additions have been modified: TiH2 and SiC… Research progress on mechanical behavior of closed-cell Al foams influenced by various TiH2 and SiC additions and correlation porosity-mechanical properties
Abstract:
- page 1, line 10: it is recommended to exchange “by means of mechanical compressive tests.” in “by means of mechanical properties.”
- page 1, line 12: please modify in “Samples with SiC = 2.8%, TiH2 = 0.4% and Al = 96.8% have the highest energy absorption while samples containing SiC = 6%, TiH2 = 0.2% and Al = 93.8% exhibit good overall foam properties (best compromise between morphology and energy absorption).”
Introduction:
- page 1, lines 21 to 30: this first paragraph in the introduction needs further, newer references – recent research studies are missing
- page 2, lines 53 to 67: this paragraph needs to be moved to the front and the paragraph lines 46 to 52 moves to the end – please add what is new in your approach to the state of art, extend your motivation…
Materials and Methods
- page 2, lines 74 to 81: “To regulate the physical microstructure [] to room temperature.” is pure theory and should be moved to the Introduction
- page 3, line 112: please make clearer what has been optimized!
- page 3, line 122: please modify “The static compression test is conducted using the MTS Insight 50, a standard testing machine to determine the mechanical properties, including compression testing of foams.”
- page 3: please add sample geometry and number of samples tested (for statistical reasons)
Results
- it is recommended to show all the 4 curves from Figure 3/4/5/6 in one diagram – that also brings the axis’s to the same font size and scale (numbers)
- Table 2/3/4/5: please comment, why there are different sample sizes? and comment on the weight loss before and after compression
- page 6, Figures 7 and 8: please enlarge the font size of the x- and y-axis and of the label
- page 8, in Figures 9/10/11/12/13/14 the font size needs to be enlarged and please check the numbers (you claim: 9/10/11/1/2/34)
Discussion
- the discussion is too short and not based on the results, rather a repeat of theory
- furthermore, the discussion includes the Conclusion – from line 314
Conclusion
- see up line 314
Author Response
Please see attached file
Author Response File: Author Response.pdf
Reviewer 3 Report
In my opinion presented problem has the significance both in scientific cognition and in engineering practice. The metal foams have many practical applications, for example as a core layer in sandwich or layers composite structures.
I recommend to accept it for publishing but after small corrections and supplements:
- stronger underline of the novelty of examined problem,
- the quality of Figures should be improved,
- the future examinations should be presented indicating that the problem is not finished and may be continued for some related issues.
Author Response
Please see attached file
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Some suggestions have been addressed – but still: the paper lacks of a scientific discussion!
Abstract:
- page 1, line 12: please modify in “Samples with SiC = 2.8%, TiH2 = 0.4% and Al = 96.8% have the highest energy absorption while samples containing SiC = 6%, TiH2 = 0.2% and Al = 93.8% exhibit good overall foam properties (best compromise between morphology and energy absorption).”
Since the range is not known – to provide number does not make a lot of sense
Materials and Methods
- page 2, lines 76 to 80: “To control [] foam solidification.” is taken from the literature and not part of your methods, should be moved to the Introduction – this part describes your handling!
Results
- it is recommended to show all the 4 curves from Figure 3/4/5/6 in one diagram – that also brings the axis’s to the same font size and scale (numbers)
…at least mention, that you have different scaling at the y-axis
- page 6, Figures 7 and 8: please enlarge the font size of the x- and y-axis and of the label
Not only enlarge the graph, also the font size needs enlarging significantly
- page 8, in Figures 9/10/11/12/13/14 the font size needs to be enlarged and please check the numbers (you claim: 9/10/11/1/2/34)
I would recommend even larger font size
Discussion
- the discussion is still too short! and is still not based on your own results, you rather a repeat the theory – need modification
- furthermore, the discussion includes the Conclusion – the Conclusion needs to be separated in an own Chapter from 319! …then you see even better, that the discussion is too short!
Conclusion
- see up line 319
Author Response
please see attached file
Author Response File: Author Response.pdf
Round 3
Reviewer 2 Report
Thank you for extending the Discusssion and seperate the Conclusion!
