Study of the Mechanism of a Stable Deposited Height During GMAW-Based Additive Manufacturing
Round 1
Reviewer 1 Report
General remarks
- Change "dry extension" to "stick out length". If it isn't a stick out length, show this in the diagram (for example complete the figure 13).
- Add spaces before units and brackets (according to general rules)
Other remarks (specific)
- Abstract lines 14-18: Too long sentence (difficult to understand). Divide into smaller ones.
- Experimental details lines 99 and 100: Please explain what was welded? What element is the information about the thickness of 18 mm?
- Line 112: In the description of the table with the results of the experiment, no basis of the calculated PLH was given. Please give the equation how did you calculate PLH.
- Line 153: The figure description lacks information about the constant welding speed.
- Line 155: In figure 4, please remove the smoothing of the lines or draw a trend line. Similarly in Figure 5 (line 158)
- Line 161: Improve the quality of pictures in Figure 6 (sharpness, histogram equalization)
- Change "weld speed" to "welding speed" in line 187, 188, 189, 190 and 394.
- Lines 262-264: Explain the basis of selection the droplet generation parameters such as: radius of spherical shape; initial velocity; frequency of emerging; droplet temperature.
- In figures from 9 to 11: at serie a) reduce the temperature scale accuracy to integer values and at serie b) increase font size on temperature scale.
- In figure 13 add elements: nozzle, current contact tip and stick out length (or dry extension if it's not a stick out length)
Author Response
Response to Reviewer 1 Comments
Point 1: Abstract lines 14-18: Too long sentence (difficult to understand). Divide into smaller ones. 

Response 1: The sentence has been changed to “A series of experiments have been carried out, when the value of the predefined layer height is set in a certain range and other parameters held constant, the total height of the thin wall produced by GMAW-based additive manufacturing is almost equal to the predefined layer height multiplied by the number of layers.”
Point 2: Experimental details lines 99 and 100: Please explain what was welded? What element is the information about the thickness of 18 mm?
Response 2: The thin wall and some models were weld with different manufacturing parameters. The element of the 18 mm thick stainless steel substrate is carbon steel.
Point 3: Line 112: In the description of the table with the results of the experiment, no basis of the calculated PLH was given. Please give the equation how did you calculate PLH.
Response 3: Predefined layer height (PLH) is the parameter which represents the distance the substrate moves after each layer is welded, it is given by estimating.
Point 4: Line 153: The figure description lacks information about the constant welding speed.
Response 4: Line 108 lists the manufacturing parameters used in experiments, the constant welding speed is equal to the travel speed: 0.011 m/s.
Point 5: Line 155: In figure 4, please remove the smoothing of the lines or draw a trend line. Similarly in Figure 5 (line 158).
Response 5: Figure 4 and Figure 5 have been changed.
Point 6: Line 161: Improve the quality of pictures in Figure 6 (sharpness, histogram equalization)
Response 6: The quality of Figure 6 has been improved.
Point 7: Change "weld speed" to "welding speed" in line 187, 188, 189, 190 and 394.
Response 7: Modifications have been completed.
Point 8: Lines 262-264: Explain the basis of selection the droplet generation parameters such as: radius of spherical shape; initial velocity; frequency of emerging; droplet temperature.
Response 8: The radius of spherical shape is estimated based on the wire diameter. The initial velocity is defined according to the literature. The frequency is calculated by the following formulas:
where r is the radius of spherical shape, f is the frequency of emerging, D is the diameter of the welding wire, VF is wire feed speed, t is the manufacturing time.
The droplet temperature is defined according to the literature.
Point 9: In figures from 9 to 11: at serie a) reduce the temperature scale accuracy to integer values and at serie b) increase font size on temperature scale.
Response 9: Modifications have been completed.
Point 10: In figure 13 add elements: nozzle, current contact tip and stick out length (or dry extension if it's not a stick out length)
Response 10: The elements have been added.
Reviewer 2 Report
Dear Authors,
although the presented research topic is not the Reviewer's field of interest, I find it very interesting and very well written and presented.
However, I'm pretty sure that there are several published paper in Applied Science journal, of excellent quality, which can be referenced here.
Regards!
Author Response
Response to Reviewer 2 Comments
Response : Thanks for your comments, the introduction has been improved.
Reviewer 3 Report
The issue of the mechanism of a stable deposited height during GMAW-based additive manufacturing included in the reviewed article is useful and important. In this context presented work can be evaluated as important to the field of mechanical engineering.
The literature background is at an acceptable level. Authors refer to actual sources and provide proper conclusions based on this analysis.
Unfortunately, the presentation method should be improved because it is not in accordance with generally accepted standards in that area. The conclusions are adequate for the analysis.
There are issues that reduce the quality of the paper:
1. The main complaint is that the paper lacks a clearly defined path to solve the purpose of the research specified in the paper title.
2. The paper requires significant changes in the organization.
Chapter 2 "Experimental details" contains both the assumptions and conditions for experimental tests and the results. This approach is illegible. Experimental conditions, material and results of experiments should be highlighted. In this regard, it should be done in the same way as for simulations.
3. Measurements shown in Figures 3 and 6 are not acceptable for this class of scientific journals.
4. How many times was the experiment repeated? What are the confidence intervals?
5. The presentation of the results must be significantly improved.
6. The simulation results are presented in an illegible way - in principle, the presentation of their results adds nothing to the work.
After improving the paper structure and quality of presentation of results, it could only be subject to thorough substantive assessment.
The work seems to be important and should be published at a quality journal, reaching to many scholars in this area. However, the comments above must be taken into account.
Author Response
Response to Reviewer 3 Comments
Point 1: The main complaint is that the paper lacks a clearly defined path to solve the purpose of the research specified in the paper title.
Response 1: The purpose of the research specified in the paper is to study the mechanism of a stable deposited height during GMAW-based additive manufacturing, the paper explains that when other parameters hold constant and the predefined layer height was set in a certain range, the height of welding bead would close to the predefined layer height, it means that the deposited height during GMAW-based additive manufacturing is stable. Each group of process parameters corresponds to a predefined layer height that can ensure the deposited height keep stable. The predefined layer height means the distance the substrate moves after each layer is welded.
-Point 2: The paper requires significant changes in the organization.
Chapter 2 "Experimental details" contains both the assumptions and conditions for experimental tests and the results. This approach is illegible. Experimental conditions, material and results of experiments should be highlighted. In this regard, it should be done in the same way as for simulations.
Response 2: Thanks for your comments, the struct of the paper has been changed.
Point 3: Measurements shown in Figures 3 and 6 are not acceptable for this class of scientific journals.
Response 3: The rules in Figure 3 and Figure 6 are not the measuring tools, they serve as reference objects that make the differences between welding beads and the differences between welding thin walls clearly. The measuring tool we used is slide calliper rule.
Point 4: How many times was the experiment repeated? What are the confidence intervals?
Response 4: The experiment was repeated more than three times. The confidence interval of the height and width of the welding thin walls is 0.1mm. The confidence interval of the arc parameters is less than 5%.
-Point 5: The presentation of the results must be significantly improved.
Response 5: Thanks for your comments, it has been improved.
Point 6: The simulation results are presented in an illegible way - in principle, the presentation of their results adds nothing to the work.
Response 6: After we found that the predefined can influence the deposited height, we want to study what causes the phenomenon. However, the internal conditions of the molten pool such as the temperature field are difficult to measure. Therefore, we decided to use Flow 3D software to simulate the welding of the first layer, the results of simulations show that with different predefined layer height, the temperature field in molten pool will change, it will influence the geometry of the welding bead including the deposited height.
Round 2
Reviewer 1 Report
none
Author Response
Thanks for your review, the results have been partly changed. Figure 14 and Figure 15 are analysis of the continuous welding process, but the information shown in the drawings is not clear enough. Text description is more detailed, so the two drawings are replaced by text.
Reviewer 3 Report
Thank the authors for the changes. Unfortunately, most of my drawings have poor quality in my copy. I hope that this will be resolved at the stage of editorial composition. However, I have a suggestion to Figures 14 and 15. What kind of results present these drawings? - analysis of test results or simulations or literature. There are no scales and axis directions on them. It should be improved.
Author Response
Thanks for your suggestion, Figure 14 shows the trades of the dry extension of the electrode during the welding process with different values of the layer height. Figure 15 shows the changes in layer height. The two drawings are analysis of the continuous welding process, but the information shown in the drawings is not clear enough. Text description is more detailed, so the two drawings are replaced by text. Thanks again for your review.
