Mechanical Properties of Ti6Al4V Fabricated by Laser Powder Bed Fusion: A Review Focused on the Processing and Microstructural Parameters Influence on the Final Properties

Round 1

Reviewer 1 Report

1. Grammar in the introduction should be proofread and revisited for clarity. For example, on line 26 there should be an “of” before AM and there are others in the section.
2. Would not use the 2020 revenue estimate on line 30, since the date has passed. Is there a different source with a revenue for a future date that you could use?
3. Line 100/104: EBM is used without prior explanation or description (electron beam melting).
4. Line 242: (REF) is mistakenly left in.
5. There is only one citation newer than 2019. How does this review differ from a Ti-6Al-4V review completed in 2-3 years ago, such as (https://www.sciencedirect.com/science/article/pii/S026412751830916X)? I would work to add more current literature, since metal AM is a very active field.
   • https://www.sciencedirect.com/science/article/pii/S2214860421005674
   • https://www.sciencedirect.com/science/article/pii/S092401362100073X
   • https://www.sciencedirect.com/science/article/pii/S2214860421003122

Author Response

Please see the attachment

Reviewer 2 Report

The manuscript entitled “metals-1735823-v1-LBPBF” dealing with AM has been reviewed. The paper has been nicely written but needs significant improvement. Please follow my comments.

 

 

1. Suggest removing figure 1 from the introduction and moving it to a better place for the present.
2. Provide more discussion and fundamental relations for figure 3.
3. Add some quantitative results to the abstract.
4. Please refer to ASTM 52900 for correct terminology in additive manufacturing.
5. Add more detail to the conclusion and explain how your findings can support the text.
6. Additive manufacturing has many advantages over the conventional manufacturing method which can be highlighted in your paper. Please read the following article and add to the introduction to show the experimental application of additive manufacturing and the advantage of this process over conventional manufacturing like machining. “Additive manufacturing a powerful tool for the aerospace industry”
7. Please update the introduction with the new publications in the field. Authors are encouraged to read and add the following new papers in the field.

• High-cycle fatigue properties of curved-surface AlSi10Mg parts fabricated by powder bed fusion additive manufacturing
• Proposal of design rules for improving the accuracy of selective laser melting (SLM) manufacturing using benchmarks parts
• Fatigue life optimization for 17-4Ph steel produced by selective laser melting
• Evolution of temperature and residual stress behavior in selective laser melting of 316L stainless steel across a cooling channel

 

 

 

 

 

Author Response

Please, find the detailed responses in attach. 

Author Response File: Author Response.pdf

Reviewer 3 Report

The review is devoted to a topic that is topical and popular among researchers, namely, additive manufacturing, Ti6Al4V alloy, and the SLM method. The review provides useful material for readers, but this paper looks unfinished. The material presented is not always well structured, succinctly and clearly described. The work contains low-quality photos. Nevertheless, the authors have done a lot of work and the article, with some revision, will be of interest to readers. My comments and suggestions, which I hope will help the authors to improve the quality of the review:

1. When listing the advantages of additive manufacturing, the authors did not mention the possibility of using topological optimization of structures and parts manufactured by SLM. This direction is very promising and relevant for additive manufacturing from Ti6Al4V alloy. Here are some articles on this topic: https://doi.org/10.3390/a15030099; https://doi.org/10.3390/app12042106; https://doi.org/10.3390/machines9120354
2. The review contains the abbreviation EBM (line 100), which is not deciphered. How is the Electron Beam Melting (EBM) method different from SLM? If the review talks about EBM, then you need to bring its features, schemes in comparison with SLM, which is shown in Figure 1.
3. In section 2 (Ti6Al4V alloy) the authors of the paper showed the microstructure of the Ti6Al4V alloy obtained only by EBM and SLM processes. At the same time, Table 1 below shows the properties of the Ti6Al4V alloy in the wrought state. I suggest the authors of the article to show the microstructure of Ti6Al4V alloy after hot and cold deformation. At the same time, the microstructure obtained by the EBM process can be removed, since it is similar to the microstructure obtained by SLM. https://doi.org/10.3390/ma15103429; https://doi.org/10.3390/met12050773; https://doi.org/10.3390/cryst12020270
4. Figure 4 is of very poor quality. It needs to be replaced with a higher resolution image.
5. In the article, not enough attention is paid to the density and porosity of Ti6Al4V alloy obtained by SLM, and this is a very important characteristic. Porosity can vary from 0.5 to 22.6% (http://dx.doi.org/10.1088/1757-899X/248/1/012012; https://doi.org/10.3390/mi13030408). This is especially true for implants in medicine. The first conclusion just speaks about the density of the Ti6Al4V material obtained by the SLM method.

Author Response

Please, find the detailed responses in attach. 

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The paper is ready to publish.

Author Response

Dear reviewer,

Thanks for your review.

Reviewer 3 Report

The authors of the review responded positively to my suggestions and comments. The paper has been significantly redesigned and is of better quality. I recommend a review for publication.

Author Response

Dear reviewer,

Thanks for your review.