Influence of Warm Isostatic Press Process on Mechanical Properties of a Part Fabricated by Metal Material Extrusion Process
, Il-Hyuk Ahn 5,* and Woo-Chun Choi 1,*
Round 1
Reviewer 1 Report
In the manuscript, warm isostatic pressure was utilized in metal ME to improve the mechanical properties of the finished part. The mechanical property and microstructure of the final part were conducted. In my opinion, the article could be published after applying a few revisions.
Comment 1: In abstract, “However, there was no change in hardness, because the temperature of the WIP process was not high enough to change the microstructure.”: Rockwell hardness has obvious change?
Comment 2: In section 3.3, the pores, cracks and secondary phase particles mentioned in the paper should be marked in the corresponding Figures.
Comment 3: In section 4.1, “This seems to be the reason that the change in the powder distribution by the polymer flow induced by the WIP process”: How? Discuss please.
Comment 4: In section 4.1, “However, even if the process conditions are further optimized, a difference in tensile strength and strain depending on the presence or absence of WIP seems likely to exist.”: Why? Has the author conducted relevant experiments?
Comment 5: In the paper, the reduction of pores generated during the process is the most important factor in improving mechanical properties. WIP is introduced to reduce porosity and enhance mechanical properties. However, less attention has been paid to how to reduce pores.
Comment 6: In section 4.2, most of the discussion is independent of the results. It is recommended that this section should be included in the introduction and appropriate adjustments should be made to the paper.
Author Response
We appreciate your careful reading of our manuscript and thank you for your valuable comments. Please find the answers to your questions and comments regarding our manuscript.
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Reviewer 2 Report
Comments on the text entitled
“Influence of warm-isostatic press process on mechanical properties of parts fabricated by metal material extrusion”
By B.Y. CHOI et al
Submitted to Applied Sciences
This paper describes the influence of a hot pressing treatment on the mechanical properties of an alloy produced by hot extrusion. It is shown that this treatment improves the yield strength as well as the ultimate strain. The hardness is little affected.
The text is quite well written, the English language seems correct to me.
The references are numerous, recent and cover well the studied field.
However, I have a certain number of remarks, questions or criticisms:
1- What is the material studied? Where does it come from? What is its composition? We can guess from the text that it is a stainless steel, but it is necessary to give more details.
2- What is the load used for the hardness measurements? This data is very important because it gives information on the volume of material explored during the test and this is very important for a material made from powders.
3- It would be very interesting to see the tensile curves and not only the numerical values of the elastic limit and elongation at break.
4- But above all, what is not clear is the position of the hot isostatic treatment in the whole process. In fact, the samples were elaborated in the following sequence: elaboration by extrusion, then debinding and finally sintering. When is the hot pressing operation performed? Can we imagine that this operation will have a different effect depending on its place in the sequence? This point is not clear at all.
In conclusion, a study that needs major modifications before a possible publication.
Author Response
We appreciate your careful reading of our manuscript and thank you for your valuable comments. Please find the answers to your questions and comments regarding our manuscript.
Author Response File: Author Response.pdf
Reviewer 3 Report
Authors investigated the effect of the heat-pressure-treatment method on the mechanical properties of 3D printed components. This treatment method is helpfull for the FDM printed components to reduce the voids and improve the interfacial properties. However, this manuscript provided limited information. The disscussions and conclusions are obvious and well known. Authors need to develop more about mechanism and show some more interesting discovery.
Author Response
We appreciate your careful reading of our manuscript and thank you for your valuable comments. Please find the answers to your questions and comments regarding our manuscript.
Author Response File: Author Response.pdf
Reviewer 4 Report
The manuscript can be improved by considering below comments:
1) Line 83: Please consider deleting the '(' and ')'. Need to consider the meaning of the sentence if delete it.
2) Line 94: The title of Table 1 must be on the same page as Table 1.
3) Line 105: The WIP process as shown in Figure 3 uses....
4) Figure 4: Need to add a legend of what is the meaning of the blue line and red line.
5) Advisable to add a general experimental flow chart at the beginning of Chapter 2 for more understanding.
6) Line 187: ...with the scale as shown in Figure 8.
7) Figure 16: The figure and title must be on the same page.
Author Response
We appreciate your careful reading of our manuscript and thank you for your valuable comments. Please find the answers to your questions and comments regarding our manuscript.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Corrections to minor methodological errors and text editing.
Author Response
Thank you for your valuable comment. As you comment, we modified the manuscript and proofread it.
Author Response File: 
Author Response.docx
Reviewer 3 Report
I read carefully your manuscript. Authors need to show the core of inovation. Beacause the HIP and WIP are well known methods. In addition, figures have to be improved carefully. Figure 2 is hard to read and caption (a)(b) is missing. Figure 3 shows the low quality. Figure 4 and Figure 5 present duplicate content. Figure 6-8 show limited information. Moreover, it wasn well known that the HIP or WIP could imporve both strength and toughness. Authors should explore the mechanisms of the improments on the mechanical properties. I believe that authors payed a lot of efforts on this work. However, we want to see more interesting contents in this paper, not "In future study...".
Author Response
Thank you for your valuable comment. As you comment, authors modified the manuscipt and proofread it.
Author Response File: Author Response.docx
Round 3
Reviewer 3 Report
Authors addressed some problems I pointed out. Now I would like to reconsider this manuscript after major revision.
1. The introduction need improvement. Some publications were recommended as follows. These papers investigated the effects of the heat treatment method for composite materials.
H. J. O'Connor, D. P. Dowling, Polym. Compos. 2019, 40, 4329.
Q. Y. Meng, Y. Z. Gu, L. Luo, S. K. Wang, M. Li, Z. G. Zhang, J. Appl. Polym. Sci. 2017, 134, 44832.
J. Wang, Q. Tan, K. Wang, S. Yao, Y. Peng, Y. Rao, Polym. Compos. 2022,1.
S. Bhandari, R. A. Lopez-Anido, D. J. Gardner, Addit. Manuf. 2019, 30, 100922.
2. The name of the Section 2-Experimental was suggested to be "Experimental procedure" or "Experimental test". Please carefully review throught the manuscript.
3. In table 2. Please change the order of the column of the "Units" and "Values".
4. Please add a photo of the real WIP equipment in Figure 4.
5. The words in Figure6-8 were too small and they were difficult to read.
6. Why the load-speed 0.36 mm/min was selected?
7. The caption of the Figure 9 need modified.
8. In Figure 16 "(d)" was missed.
9. Author invesitgated the secondary-phase particles before and after WIP treatment. What is the difference? Please dicussed more specificly.
10. In Figure 16, error bar of the results need to be presented.
Author Response
We appreciate your careful reading of our manuscript and thank you for your valuable. As you comments, we modified the manuscript.
Author Response File: Author Response.docx
