The authors investigated the effect of 2 different organic compounds (PA and CM) in 3 different concentrations (0.5, 1, 2 and 3 wt%) on fabrication of Fe-Al intermetallic foams. The subject fits to the Special Issue and is of high interest. Overall, the manuscript reports about an interesting piece of work, and is well organized and synthetic in text (not redundant or too long). However, some clarifications, partly in language and partly in presentation (redundant or inappropriate illustrations) are required before acceptance.

1. Line 46: remove newline.

2. Lines 49-50: replace "and due to their volumetric expansion during combustion allowed to form highly porous materials" with ", which allowed to form highly porous materials thanks to their volumetric expansion during combustion"

3. Fig.1 text: in text-box "the regulating punch fence" remove "the".

4. Line 56: "combustion synthesized", insert hyphen in between

5. Lines 60-63: “As expected, the final porosity of obtained sinters is lowest for samples sintered without additives and the highest for samples doped 3 wt. % of chemical compounds regardless of whether palmitic acid or cholesteryl myristate was used”: for the sentence to make sense, the final “was used” shoud be removed.

6. I do not like, and there is no reason for, that the level of zero additive porosity is represented as an horizontal bar spanning all x axis, in Fig.3: just represent as the other datapoints, i.e.e as a single point with its error bars, corresponding to x axis (chemical compound wt%) value =0.

7. About Fig.3 and related text: The highest wt% seems to give the highest % porosity, but: - the trend is not monotonic: the second highest porosity seems to occur for the second lowest (apart from 0) compound concentration, 0.5; - so, probably the differences are, in most cases, not statistically significant: the authors, in addition to showing mean+-std. dev bar, should analyze sets of raw data (all datapoints for each case) and carry out ANOVA with pairs comparisons, and say which couple are statistically significant in difference (at 0.05 level). Is, thus, case of concentrations 3% really different from 0.5? Maybe not. From 1? Probably yes. Please add this part and few consequent comments.

8. Line 74: ": (a)" change to “(a)”

9. Line 76: "(d))" change to "(d)."

10. Table 1: for all values, replace "," with "."

11. Table 1 values: should be approximated differently, given the error: e.g. 36.20+-0.72 should read 36.2+-0.7 43.08+-1.03 become 43.1+-1.0, and so on 47.15+-0.96 is more difficult: 47.2+-1.0

12. Line 64: “, Kirkendall” change to “, thus either Kirkendall”

13. In each first occurrence of the respective acronym, the full working should be defined first. So, for example: Line 64: “SEM” replace with “Scanning electron microscope (SEM)” Line 83: “XRD” replace with “X-ray diffraction (XRD)” Line 85: “EDS” replace with “energy-duspersive spectroscopy (EDS)”

14: Do not define acronyms in the abstract, not self-standing: So, remove “(PA)” and “(CM)” on line 18 and 19, respectively.

15. Remove “(PM)” from line 48: this acronym is not used in the manuscript after that.

16. Line 89: “diffraction pattern (XRD)” change to “XRD pattern”

17. Line 101: “3” change to “4”

18 Same line: “Thus, only amorphous, carbon containing, phases” change to “Thus, only amorphous carbon-containing phases”

19. Line 103: “methods poor accuracy” change to “poor accuracy of the technique”

20. Frankly speaking, in Fig.5 the different abundance of elements should appear as maps of different colors (e.g. red for Fe, blue for Al) overlayed on different SEM imaged areas. However, let’s say that the reader will believe the ‘arrows’ assignement.

21. Fig.6 and 7 are quite redundant: they are not strictly useful to the paper, also given the limitation pointed at item 20 above, that no color elemental mapping is shown. So I would really think about removing or at least limiting their number. For example, in both cases (MC for Fig.6 and PA for Fig.7), at both concentrations (0.5 and 3) a low and high magnification image is shown, and the EDS is taken only from the high magnification image; (additionally, it is not clear if the high mag image is taken from the same region, as a closeup of the low mag image: if so, a rectangle with the are of the hi mag image should be overlaid on the – previous – low mag image). Everything would actually be much easier, if the all the low mag images are removed; alternatively, all the hi mag images may be removed:

22. in fact, in ant case, also the arrow pointing to the EDS table should be removed, as it is again not clear where it comes from: a single point, at the base (starying point) of the arrow? Or the whole image area? In the former case, is it really representative of the specimen? Finally: I would remove either low or (maybe better) high mag images, so halving them (from 8 to 4); the thus reduced 4 SEM images (2 additives x 2 concentrations) could be combined in a single figure, so from fig.6 and 7 to 6 only.
The info about EDS composition can then be presented separately, better in the form of a plot: a bar plot would do the job nicely: 4 groups of 4 bars (1 bar for each element).

23. Line 122: “mentioned above chemical additives combustion temperature” change to “the combustion temperature of the above-mentioned chemical additives”

24. Same line: “is” change to “was”

25 Line 123: “Volumetric expansion of the gases, increased pressure” change to “Volumetric expansion of the gases occurred accompanied by increased pressure,”

26. Line 128: Insert neline before “Therefore”

27. Line 132: “agents, however” too long, split: “agents. However”

28 Lines 133-134: “elements what seemed previously as unavoidable” change to “elements, what previously seemed to be unavoidable”

29 Line 136 “is while” change to “occurs when”

30 Line 137: “other, undesired” remove comma

31 Line 139 “while” change to “when” Same at line 144.

32 Line 146: “were” change to “are”

33. Line 149. “However the shorter hydrocarbon chain, the more eager combustion undergo and the lower temperature of sintering is effective for the foaming” change to “However, the shorter the hydrocarbon chain, the easier is the combustion, and the lower is the sintering temperature effective for the foaming”

34 Line 162: “Φ25 mm” change to “25 mm diameter”

35 Line 168: “scanning microscope” change to “SEM”

36 Line 173: “compounds” change to “coumpounds such as palmitic acid and cholesteryl myristate”