Simulation of the Influence of the as-Deposited Wall Thickness on Arc Shape and Stability during Wire Arc Additive Manufacturing

Round 1

Reviewer 1 Report

The development of additive manufacturing technologies improves the modern industry. The production of components from wire filament using an electric arc source is a cost-effective and quite flexible process. It is also worth noting that in this paper, along with experimental studies, modeling of the 3D printing process is presented. This significantly increases the value of the data obtained, as it allows the development of digital manufacturing technologies.

 

1. The first section provides a literature review on the current state of WAAM research and technology. The problem on the solution of which the authors are working is formulated. 14 sources cited are new. In general, the review is done quite well.

2. The second section provides a mathematical model and a technique for modeling the 3D printing process, as well as materials and a technique for experimental verification of the simulation results.

The methods are well and detailed. The illustrations are of high quality.

3. The third section presents the results of modeling and experimental studies.

The illustrations are of high quality. The description of the results is detailed.

This section also discusses the new results obtained. When discussing, the authors make a comparison with known literature data.

4. The fourth section draws conclusions based on the new results obtained.

 

Notes:

1. There is no specific goal and objectives of the work in the introduction. Only the problem the authors are working on is given. It also lists the actions taken.

2. Figure 6 is divided into two pages. Arrange it on one page for a better presentation of information. It is also worth compiling Figure 7, in which the signature has moved to a separate page.

3. Figure 3 caption should be revised. Sign where exactly is the experimentally observed arc, and where is the calculated one.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear Authors,

Congratulations on your work, which is focused on a very interesting subject. As any other paper in this phase, there are some amendments to do, whose can improve the overall quality of your paper. Thus, I'm providing below some comments and suggestions, trying to collaborate by this way in improving your paper:

1. The Abstract doesn't clearly state the literature gap found, as well as the main motivation to develop this work. Thus, please clearly state the gap found in the literature in the Abstract, Introduction and Conclusions. The main goals are also not clear in the Abstract.

2. The novelty brought by your work is also not properly pointed out. Thus, please state clearly the novelty that your paper represents for the scientific community, stating as well if your contribution is exclusively scientific or if there was some practical motivation behind the development of your work. Any industrial application based on this work should also be pointed out.

3. Please avoid the use of large sets of references in the Literature Review.

4. There are a lot of grammatical errors throughout the manuscript. An examples: "The finite element modelling method were used...". Please ask for a professional proofreading process by a Native English Speaker.

5. Please don't use contractions in scientific docs (Example: isn't).

6. I understand that in simulation, assumptions are always needed. However, the 6 assumptions considered in this work are narrowing the results and masking the usual situations, giving rise to results that are not close to the main target. Is it possible to reduce the number and increse the quality (less restrictive) of the assumptions?

7. Please use always a space between values and units (examples: 16mm, Figure 1, δ=10.2mm, 14.3mm, Figure 3, Figure 4, etc.).

8. In the GMAW, please point out the droplets transfer mode used/observed (spay, short-circuit, etc.).

9. Please justify the use of 20 L/min of shielding gas, because 12 L/min is usually perfectly enough in closed environments.

10. In Table 1, some parameters are constant. Why to repeat them in all lines? Please describe these variables in text before the table and remove them from the table.

11. No discussion of the Results is presented. This is crucial. You need to compare your results with others previously achieved by others, even in dissimilar situations.

12. Conclusions could be improved, highlighting in a better way the novelty of the work, taking into account what has been published in this field so far.

 

Best wishes.

Best regards,

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 3 Report

This manuscript presents a study about the effects of the characteristics of the arc shape, temperature field, velocity field, current density, and the electromagnetic force on the Wire and arc additive manufacturing (WAAM) technology. From this study, several interesting conclusions about the relation between the wall thickness and the arc diameter were obtained.

Overall, the manuscript is well written. The novelty of the work is highlithed and the conclusions are interesting for ingeneering purposes. Consequently, I suggest to accept it after minor revisions. My main comments to improve the manuscript are, as follows:

(1) Introduction: improve the explanation of the WAAM method importance.

(2) Mathematical models: In a reasonable manner, the assumptions are well stablished. 

(3) Methods: some of the deposition parameters are not justified in the manuscript. Therefore, an explanation about the selection method used should be included in the revised version. In addition, in order to promote the interest of the mathematical model and to help the model to be reproducible, the file with the mathematical calculations (code) should be included as supporting material.

(4) Results and discussion: this section is well written and the main aspects concerning the research are discussed. However, there are very few references in the actual version of the manuscript in this section. How about the results reported by other authors in similar studies?

(5) Conclusions: I recommend to maintain this section as it is.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Congratulations for the improvements!