Development and Characteristics of New Biobased Magnesium Composites

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Manuscript Metals-4160650 concerns the preparation of a magnesium composite in which the reinforcing phase is dried mango leaf powder. The authors present a method for the preparation of waste biomaterial, the production and characterization of a magnesium composites. Although the article addresses the currently fashionable topic of using waste materials, it has several flaws that need to be corrected before publication.
Remarks
1. The Materials and Methods Section lacks information on the sieves used to prepare biomass powder. Therefore, there is no information on the grain size of the dried biomass powder. Please provide this information.
2. No information on the characteristics of the biomass powder. The starting material should be thoroughly characterized. The authors should provide the results of the proximate and ultimate analysis performed for the biomass powder used. This is important because the composition of biomaterial can vary depending on many factors, such as soil type, fertilization or geographical origin.
3. The authors mentioned hardness tests of various leaves conducted by other authors (lines 65-67), but the cited work [19] does not contain data on mango leaves.
4. Please answer the following questions regarding the methodology (lines 173-174):
Why was PBS used for corrosion testing?
Why were the tests conducted at 37 °C?
What was the reason for periodically cleaning the sample surfaces every 24 hours during corrosion testing?
Minor remarks
5. Figure 3 requires correction:
In the upper part of the Figure, some closed circles corresponding to the diffraction peaks are shifted relative to the peaks themselves.
6. Figure 4:
Are the authors sure that the tested samples are sufficiently homogeneous and that each point on the surface can be assigned an identical composition?
7. The bibliography should be organized according to the rules established in this journal.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The article presents an approach to develop the metal-based composites containing biomass with naturally locked carbon, and establishes the fundamental processing–microstructure–property relationships in a biobased magnesium composite, leveraging Powder Metallurgy (PM). The authors argue that there are few studies in the literature on the subject addressed, which is reflected in the rather old bibliographic study. In this context, I believe that more thorough research should be done to improve the quality of the work and provide readers with a clear view of the entire research. I recommend some minor revisions to improve the quality of the present paper for publication in Metals.

• The introduction needs small improvement; this section provides general information about the potential for Mg used as a biomaterial in various sectors. This section should briefly discuss the challenges and limitations of current approaches to develop of metal based composites, which contain biomass with naturally locked carbon.
• The materials and methods sections describe in detail the materials and the parameters for the synthesis of biobased composites. I consider that Fig. 1 does not fit into this section, and should be presented in the Results section.
• The results and discussion should not contain section 3.1 Synthesis, as there is a dedicated section. I recommend a rigorous analysis of the data; at first glance, the results presented are difficult to understand. Perhaps Fig. 4 should be explained and detailed in the SEM image. This revision could improve the clarity and interpretation of the EDS analysis. The figures should have a unified appearance, and some of them should be improved by indexing with value and information.
• The Conclusions section is well-detailed and justified. Although future directions are also presented, I would ask the authors to specify the extent to which these results will impact research and the field of application they target.
• The Bibliography should be expanded, with more current references.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Remarks

Since the authors do not want to reveal the mesh size of the sieve, I propose replacing the sentence (lines 89–90): 
"The resulting powder was sieved three times to remove coarse particles." 
with the sentence: 
"The resulting powder was separated from the coarse pieces of the midrib that were not well milled"
or a similar sentence.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf