Effects of Process Parameters on Cold Spray Additive Manufacturing of Quasicrystalline Al93Fe3Cr2Ti2 Alloy
, Felipe B. Do M. Carmelo 2, Erlifas M. Rocha 1, Claudio S. Kiminami 1,2 and Piter Gargarella 1,2,3
Round 1
Reviewer 1 Report
Some comments are listed below.
1) Please use the consistent Coating ID, e.g. difference between Table 1 and the other tables.
2) The meanings of abbreviations of CS, XRD, STEM, BSE, EDX and SLM are missing.
3) What are the commercial models of CSAM and nozzle used for this research? If the nozzle apertures cannot be given, other information must be given to describe the nozzle, e.g. models of the nozzles.
4) What is the processing parameters of sandblasting?
5) Please give the information of EDX equipment.
6) In the section 3.2, the PV of coating 3 is 588m/s, while it is 600m/s in Table 1. Which one is correct? If the later one is correct, the explanation in the section 3.2 is questionable.
7) What is the meaning of ",3" in the lables in Figure 1?
8) What is the correct gas temperature of coating 7, 475C in the section of 3.2 or 425C in Table 1?
9) In Figure 6, the peak of theta phase can be observed in coatings 3, 4, 5, 6 and 7. However, the authors stated that it only showed in coatings 4, 6, and 7. Why?
10) The chemical composition of as-atomized powders should be given in Table 3 for comparsion. The composition shown in Table 3 is not the same as the nominal composition in the section 2.
11) Please use the stacked lines to show the DSC curves including the DSC curve of as-atomized powders.
12) The deviation of microhardness given in the abstract and conclusion is much smaller than those in Table 4. How to obtain this value?
Minor editing of English language is required.
Author Response
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Author Response File: 
Author Response.docx
Reviewer 2 Report
Dear Authors,
please consider the following comments/suggestions:
1) Please, check the reference style and indications reported in the instructions (In the text, reference numbers should be placed in square brackets [ ], and placed before the punctuation; for example [1], [1–3] or [1,3]. References should be described, depending on the type of work). Revise references within the text and the list at the end. For instance you have “..layer-by-layer cold-sprayed part [1], [2], [3].” or “[1] Y.-K. Kim, K.-A. Lee, Effect of carrier gas species on the microstructure and compressive deformation behaviors of ultra-strong 316 pure copper manufactured by cold spray additive manufacturing, Journal of Materials Science & Technology. 97 (2022) 264–317 271. https://doi.org/10.1016/j.jmst.2021.04.062.”
2) Line51-54. Please revise the sentence. A part seems missing.
3) Line 65-66. Be careful how syllables are divided.
4) Line 82, 88, 94, 105: it is suggested to do not use the “we form” in writing the manuscript.
5) Line 104: how were chosen the process parameters values? Why exactly that ranges? Please specify.
6) Line 105: “..a lower one= “A”, and a higher one= “B”.” the authors could replace = with named.
7) Figure and tables have to be placed close to the text where they are cited. For table please consider the instruction for authors “To facilitate the copy-editing of larger tables, smaller fonts may be used, but no less than 8 pt.”
8) Line 111 - Fig. 1 caption: please add within the caption the description of a) and b).
9) Fig 1b is too big.
10) Line 115: Add a little space after the table caption. You could also add the legend within the caption. Futhermore, add the units directly on the first line of the table, where the paramenter is specified.
11) Line 127: please revise the sentence (“..was used to take a 18 pictures along..”).
12) Line 153: Where this values “..(varing locally of about 48-85 μm),..” come from?
13) Figure 3: please set the same dimensions for all 7 images. Same comment for Figure 4, try to set the same height of the images on the right and on the left side of the table.
14) Line 179-180: “The exception is coating 3, where the poor layer adhesion is revealed by the presence 179 of cracks, and it’s a consequence of the lowest particles’ velocity (588 m/s).” Actually coating 1 had the lowest velocity (588 m/s), not coating 3. Please revise the text and update the considerations on the obtained results, since any crack is visible in the first sample.
15) Figure 4: it wold be better to add a) and b) at the end maintaining just the coating number on the images. In this way the reader will clearly understand that the column on the left has magnification of 100um, while images on the right have magnification of 10um. Please revise also the figure reference within the text because it’s quite confusing (use the same style. See Figure 4 (b) and Figure 1b)).
16) There is such kind of comparison between the powder microstructures shown in Fig.4b and Fig1b. Actually, they are of different magnification, therefore the similarity is not clearly visible. Please revise.
17) It could be better to indicate the 10um image from which part of the 100um image was taken.
18) A deep description of the microstructure analysis should be provided.
19) Remind to put the figures close to the sentences where they are commented. For instance, figure 5 should stay after line 191. The same for table 3, after the current line 198.
20) Line 216: for coating 7 a temperature of 425°C was used, according to Table 1, and not of 475°C. Please revise the results.
21) Fig 6-7 and others: Please use the same font and font size for all graphs in the manuscript.
22) Line 233: please revise the sentence “..one can see the second heating cycle did not show any exothermic event..”.
23) Fig 7: it is suggested to use a thinner thickness for the curves in order to make them clearer.
24) Fig 8: The caption is too long. Add just the main info the other could be added in the manuscript directly. Furthermore, please organise better the whole figure. Considering how is it organised now, you should add letters on the other four figures below a) and b).
25) Line 246: “..such as Figure 4 side (b),..” that’s why it is important to distinguish the column. In that case you can write directly Figure 4 b).
26) Line 260: “The microhardness values vary from 250 to 280 HV”. Consider what actually indicated in Table 4.
27) Conclusions should be enriched.
Comments for author File: 
Comments.pdf
Author Response
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Reviewer 3 Report
Comments
Title - Effects of Process Parameters on Cold Spray Additive Manufac- 2 turing of Quasicrystalline Al93Fe3Cr2Ti2 Alloy
The paper is well-written and discussed everything in detail. The project also has good industrial relevance.
1. Author needs to justify the novelty of the research specifically somewhere in the manuscript.
2. Applying more pressure is creating a good fusion between the metal powders. But pressure might change the morphology of the powder particles and also crush them to create the porosities. How would you address this concern?
3. Please provide the high-magnification images of samples 4, 5, 6, and 7 to understand the morphology of the particles.
4. As Samples 4, 5, 6, and 7 showed good fusion which means they are well compacted. This might increase the hardness values. Kindly mention how many times you indented the sample for checking the hardness.
Author Response
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Round 2
Reviewer 1 Report
In Fig. 7b, "Heat Flow (u.a.)" should be corrected to "Heat Flow (a.u.)" to indicate arbitrary units. In order to compare the heat released from the DSC peaks accurately, it is necessary to provide the sample mass or specify the unit of heat flow, such as W/g or V/g.
As the authors stated in Fig. 7a, the broad exothermic peak at ca. 400°C is associated with the metastable transformation of the i-phase. However, the broad peak actually consists of two peaks, one at ca. 400°C and the other at ca. 470°C. It is unclear whether both of these peaks are related to the metastable transformation of the i-phase.
In Fig. 7b, two peaks can be observed at higher temperatures (ca. 450°C and ca. 560°C) compared to Fig. 7a. The reason for this discrepancy is not explained. Assuming that the heat flow curves in Fig. 7 are normalized by sample mass, it is expected that the heat released for the high-temperature peak would be higher than that for the low-temperature peak. However, the opposite trend is shown in Fig. 7a, except the curve of coating 5. The inconsistency between the trends of the peaks in Fig. 7a and Fig. 7b needs to be addressed and clarified.
Author Response
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Reviewer 2 Report
Dear authors,
the quality of the manuscript has been improved, but just few comments are pending. Please consider them, you may find red text in the file.
Regards
Comments for author File: Comments.pdf
Author Response
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Reviewer 3 Report
The comments are properly addressed. The paper is ready to be published.
Author Response
Dear reviewer, Thank you very much for your second revision of our paper.
Best regards,
Authors,
