Effect of Process Factors on Tensile Shear Load Using the Definitive Screening Design in Friction Stir Lap Welding of Aluminum–Steel with a Pipe Shape
Round 1
Reviewer 1 Report
1) The title is too long for an academic article, please cut it down to a suitable length.
2) There are some language flaws. Please check the whole manuscript.
3) I don't really understand Figure 3, and there is even no discussion around this figure.
4) I think some figures should be dotted lines, while the authors used continuous lines, such as figure 4.
5) The discussion for some figures is deficient, such as figure 5.
6) Similar to figure 3, the information in figure 7 is not clear.
7) I suggest the authors redraw figure 6 using other colors.
Author Response
PUSAN NATIONAL UNIVERSITY (PNU)
Graduate School of Convergence Science, Pusan National University, busan, Republic of Korea, 46241
TEL: +82.51.510.2361
FAX: +82.51.510.7396
E-mail: [email protected]
24 Sep., 2021
Dear MDPI Materials Editorial Office
Topical Editor
Dear Editor,
We appreciated your efforts in considering the manuscript by providing reviewers comments/suggestions which helped us greatly while revising the manuscript to improve scientific as well as technical quality of the revised manuscript ID: materials-1385885.
According to the reviewers’ comments/suggestions, we carefully have revised the manuscript. We also provided our point-by-point responses to the comments. We are sure that revised version of the manuscript can be of journals standard and as per reviewers’ expectations. The revised text in the new manuscript is marked in blue color.
We would like to receive “the letter of acceptance certification” as soon as possible. Thank you very much for your help in advance.
Sincerely yours,
Head/Professor Myungchang Kang
School of Convergence Science
Pusan National University (PNU)
63 Busandaehak-ro, Geumjeong-gu, Busan, Republic of Korea, Zip: 46241
E-mail: [email protected]
Reviewer #1:
Comment (1) The title is too long for an academic article, please cut it down to a suitable length.
Our response (1) Thank you for suggestion, accordingly, in revised manuscript suggested title has been modify.
[Modification of the manuscript]
" Effect of Process Factors on Tensile Shear Load using the Definitive Screening Design in Friction Stir Lap Welding of Aluminum-Steel with Pipe Shape " in Title.
Comment (2) There are some language flaws. Please check the whole manuscript.
Our response (2) Authors respect reviewer’s keen observation, typo-mistake and flaws has been corrected.
[Modification of the manuscript]
" tool penetration depth " on page 1, line 21 and keyword.
" tool plunge stage " on page 2, line 83.
" CuAl2 " on page 2, line 94.
" CuAl2 – CuAl–Al4Cu9 " on page 2, line 96.
" They also " on page 2, line 97.
" a pin length " on page 3, line 113.
" plunge " on page 3, line 154.
" Si" on page 4, Table 1.
" [54-55]. " on page 5, line 190.
" 2" on page 8, Table 5.
" 3.1. Tensile Shear Load Characteristics " on page 7, line 248.
" the tool penetration depth " on page 9, line 317.
" the dwell time " on page 9, line 322.
" 3.3. Characteristics Between the Factors of a Definitive Screening Design" on page 9, line 331.
" high-strength steel " on page 14, line 649.
" tool rotational speed, tool welding speed " on page 16, line 727.
Comment (3) I don't really understand Figure 3, and there is even no discussion around this figure.
Our response (3) Accordingly, in revised manuscript the title and explanation of Figure 3 has been modify.
[Modification of the manuscript]
" Figure 3. Main effect plots for tensile shear load. " on page 8, line 298.
" This figure shows the average value of tensile shear load according to the number of levels of each of the six factors: tool rotation speed, welding speed, plunge speed, dwell time, plunge depth, and tool penetration depth.
At a given level, it is possible to screen for factors that do not affect TSL with DSD. Tool rotational speed (A) and welding speed (B) are grayed out in the main effects plot in Figure 3 as they have no effect at any given level. Therefore, the tool rotational speed (A) and welding speed (B) are excluded from the process of finding the maximum value of TSL, and the maximum value of the TSL is found as the remaining four factors that affect it. At a given level, the plunge speed is indicative of the curvature, which is optimal. It was found that dwell time and plunge depth had a negative effect, and only the tool penetration depth had a positive effect. The desired result is high tensile shear load, so the maximum TSL is achieved at a plunge speed of 6.5 mm/min, a dwell time of 3.0 s, a plunge depth of 0.0 mm and a tool penetration depth of 1.0 mm. " on page 8, line 291~315.
Comment (4) I think some figures should be dotted lines, while the authors used continuous lines, such as figure 4.
Our response (4). In Figure 4, the change in the penetration depth of the tool is divided into a solid line, a broken line, and a dash-dot line.
Accordingly, in revised manuscript the explanation of Figure 4 has been modify and the order of the figures has been changed for consistency of explanation.
[Modification of the manuscript]
" Figure 4 shows the interaction for TSL. This is according to the interaction between factors in the regression equation of the TSL of Equation (1). Figure 4(a) is a diagram with the interaction between the plunge speed and the tool penetration depth(C × F) for TSL. In the equation, it is expressed as a curved surface as an effect of the square term of the plunge speed, and it can be seen that an optimal value exists within a given range. It shows the positive effect of increasing TSL with increasing tool penetration depth over the entire range at a given level. Figure 4(b) is a diagram of the interaction between dwell time and tool penetration depth(D × F) for TSL, where TSL increases with increasing tool penetration depth for dwell times greater than 4 s. On the other hand, when the dwell time is less than 4 s, it shows that the TSL decreases as the tool penetration depth increases. " on page 9, line 332~341.
Comment (5) The discussion for some figures is deficient, such as figure 5.
Our response (5). Accordingly, in revised manuscript the explanation of Figure 5 has been modify and the order of Figure 5 has been changed for clarity of explanation.
[Modification of the manuscript]
" Figure 5 shows a contour plot for TSL, and in order to examine the effect of a given factor, fixed values ​​of the remaining factors were selected by considering the main effects plot of Figure 3.
Figure 5(a) shows the plane contour plot of the plunge speed and the tool penetration depth for TSL. A dwell time of 5 s and a plunge depth of 0 mm were chosen for the fixed values ​​of the remaining factors. On the contour plot you can find the dwell time and tool penetration depth that maximize the TSL. Over the entire range of a given plunge speed, TSL increases with increasing tool penetration depth. Over the entire range of a given tool penetration depth, TSL increases with increasing plunge speed and decreases after reaching a maximum value. The high TSL value at low plunge speed and high tool penetration can also be seen in the main effect plot in Figure 3. Figure 5(b) shows the plane contour plot of the dwell time and the tool penetration depth for TSL. A plunge speed of 7 mm/min and a plunge depth of 0 mm were chosen from the main effects plots in Figure 3 as fixed values ​​for the remaining factors. On the contour plot you can find the dwell time and tool penetration depth that maximizes TSL. Over the entire range of a given tool penetration depth, increasing the dwell time decreases the TSL. For dwell times of less than 4 seconds in a given range, the TSL decreases with increasing tool penetration depth. For dwell times greater than 4 seconds in a given range, TSL increases with increasing tool penetration depth. It can be seen that in a given range, a maximum TSL value of about 2,600 N appears at a dwell time of 3 s and a tool penetration depth of 0 mm. Figure 5(c) shows a plane contour plot of plunge speed and dwell time for TSL. A tool penetration depth of 0.5 mm and a plunge depth of 0 mm were chosen from the main effects plots in Figure 3 as fixed values ​​for the remaining factors. On the surface plot you can find the dwell time and plunge speed that maximize the TSL. Over the entire range of a given plunge speed, increasing the dwell time decreases the TSL. Over the entire range of a given dwell time, as the plunge speed increases, the TSL increases, reaching a maximum value and decreasing again after reaching the maximum value. The high TSL value at low dwell time and maximum plunge speed can also be seen from the main effect plots in Figure 3. It can be seen that a maximum TSL of about 2,450 N in a given range appears at a dwell time of 3 s and a plunge speed of 6.3 mm/min." on page 9, line 393~ 435.
Comment (6) Similar to figure 3, the information in figure 7 is not clear.
Our response (6). Accordingly, in revised manuscript the explanation of Figure 7 has been modify.
[Modification of the manuscript]
" Figure 7 shows the reaction optimization for TSL. Among the factors in Fig. 3, the tool rotation speed (A) and welding speed (B), which are factors that do not affect TSL, are not considered in the reaction optimization of Figure 7. Therefore, the response optimization value of TSL is found as the remaining four factors affecting TSL. The maximum and minimum levels in the experimental range for each factor are shown, and the maximum value of TSL is found within the combination of these four factors. Using the response optimization tool and the overall satisfaction function = 1 in Equation (5), the optimal conditions for factors maximizing TSL while satisfying the lower limit [2,300N] are shown. In the response optimization analysis, the optimal values ​​of the derived response variables of 4 factors that satisfy the optimal conditions (mean TSL 2775.49N, maximizing overall satisfaction [1.0]) are shown. The optimum value of Cur for each factor maximizing TSL is at a plunge speed of 5.7273 mm/min, a dwell time of 3.0 s, a plunge depth of 0 mm, and a tool penetration depth of 0 mm. This value lies between the maximum and minimum values ​​of each factor level. It can be seen that the closer to the maximum value of the plunge speed, the shorter the dwell time, the lower the plunge depth, and the deeper the tool penetration depth, the closer the composite satisfaction is to 1 and the higher the TSL." on page 13, line 601~617.
[Additional Comment] FINALLY, I ALSO RECOMMEND THAT THE AUTHORS HAVE THEIR MANUSCRIPT CHECKED BY AN ENGLISH LANGUAGE NATIVE.
[Our response] We got our manuscript corrected by a native speaker. We attached the certificate of English editing as follows.
[Our additional response]
- We have given detailed explanations in Figures 4 and 6 of the DOE results to help the reader understanding.
- We present the % error to show the accuracy of the experiment.
- We presented a method for surface treatment and aluminum oxide removal in the experimental preparation process.
- A clamp that can fix the pipe during the experiment was designed, and the method is registered as a Korean patent (10-2025400). For better understanding, related pictures of fixing the pipe with left/right chucks and clamping are attached.
- The difference between the tensile strength and shear load of the fracture test characteristics was explained and pictures were presented.
- The method for selecting the experimental value of the process variable has been described in detail.
- Using the DSD method, the number of experiments was drastically reduced, making it possible to conduct economical experiments. In this regard, the limitations in which existing researchers could not test multiple process variables at the same time were explained.
Finally, we are grateful to the referees for the comments that helped us improve the quality of our manuscript. The related changes in the manuscript were marked with Blue color. We are reply to the referee’s comments on a point by point basis.
We hope that these revisions are satisfactory and that the revised version will be acceptable for publication in Journal of Materials.
Thank you very much for your work concerning our paper.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Review of the article: "Effect of Process Factors on Tensile Shear Load using the Definitive Screening Design Method in Friction Stir Lap Welding of Dissimilar Cast Aluminum – High-Strength Steel with Pipe Shape"
Dear Authors: “Effect of Process Factors on Tensile Shear Load using the Definitive Screening Design Method in Friction Stir Lap Welding of Dissimilar Cast Aluminum – High-Strength Steel with Pipe Shape”. I find the article interesting and scientifically prepared properly. After reading its content, I feel a bit unsatisfied in aspect of microstructural research. In my opinion, it would be good to define what is happening at the welding/merging zone of two materials. But according to the assumptions made in the work, I know that this was not the main purpose of the work. Comments on the editing side of the work which, in my opinion, should be improved:
- The title is too long, I propose to shorten it.
- The literature review is quite extensive and correct. There are references in the text to a reference number that is not included in the list. Please, correct the list and number the references.
- The chemical composition of table 1 lacks the main components of the tested materials. Please correct this.
- Table 5, please specify whether the error given in Table 5 is expressed as a percentage. This does not appear in the table. Perhaps it would be good to add how he was obtained?
- The description of fig. 3 should be changed and inform the reader exactly what it shows,
- In fig. 6, please indicate the accuracy with which the given planes were obtained. On the basis of how many specific data they were created. - Regarding microstructural studies, it would be good to carry out more detailed study of the places marked with Hooking (fig. 8 and fig. 9), After correction
Author Response
PUSAN NATIONAL UNIVERSITY (PNU)
Graduate School of Convergence Science, Pusan National University, busan, Republic of Korea, 46241
TEL: +82.51.510.2361
FAX: +82.51.510.7396
E-mail: [email protected]
24 Sep., 2021
Dear MDPI Materials Editorial Office
Topical Editor
Dear Editor,
We appreciated your efforts in considering the manuscript by providing reviewers comments/suggestions which helped us greatly while revising the manuscript to improve scientific as well as technical quality of the revised manuscript ID: materials-1385885.
According to the reviewers’ comments/suggestions, we carefully have revised the manuscript. We also provided our point-by-point responses to the comments. We are sure that revised version of the manuscript can be of journals standard and as per reviewers’ expectations. The revised text in the new manuscript is marked in blue color.
We would like to receive “the letter of acceptance certification” as soon as possible. Thank you very much for your help in advance.
Sincerely yours,
Head/Professor Myungchang Kang
School of Convergence Science
Pusan National University (PNU)
63 Busandaehak-ro, Geumjeong-gu, Busan, Republic of Korea, Zip: 46241
E-mail: [email protected]
Reviewer #2:
[General review] Dear Authors: “Effect of Process Factors on Tensile Shear Load using the Definitive Screening Design Method in Friction Stir Lap Welding of Dissimilar Cast Aluminum – High-Strength Steel with Pipe Shape”. I find the article interesting and scientifically prepared properly. After reading its content, I feel a bit unsatisfied in aspect of microstructural research.
In my opinion, it would be good to define what is happening at the welding/merging zone of two materials. But according to the assumptions made in the work, I know that this was not the main purpose of the work. Comments on the editing side of the work which, in my opinion, should be improved:
[Our response] We greatly appreciate the reviewer’s summary and evaluation of our manuscript.
Comment (1) The title is too long, I propose to shorten it.
Our response (1) Thank you for suggestion, accordingly, in revised manuscript suggested title has been modify.
[Modification of the manuscript]
" Effect of Process Factors on Tensile Shear Load using the Definitive Screening Design in Friction Stir Lap Welding of Aluminum-Steel with Pipe Shape " in Title.
Comment (2) The literature review is quite extensive and correct. There are references in the text to a reference number that is not included in the list. Please, correct the list and number the references.
Our response (2) Authors respect reviewer’s keen observation, no. of reference has been corrected on page 17, line 796~.
Comment (3) The chemical composition of table 1 lacks the main components of the tested materials. Please correct this.
Our response (3) Authors respect reviewer’s keen observation, chemical composition has been corrected.
[Modification of the manuscript]
" Si " in Table 1.
Comment (4) Table 5, please specify whether the error given in Table 5 is expressed as a percentage. This does not appear in the table. Perhaps it would be good to add how he was obtained?
Our response (4) Thank you for suggestion, accordingly, in revised manuscript suggested error has been added.
[Modification of the manuscript]
" The error (%) of the pre-correction model is 100 - [R-sq ](%) = 3.10 % and the error (%) of the modified model is 100 - [R-sq (adj)] (%) = 6.73 %. " on page 7, line 269-271.
Comment (5) The description of fig. 3 should be changed and inform the reader exactly what it shows,
Our response (5) Accordingly, in revised manuscript the title and explanation of Figure 3 has been modify.
[Modification of the manuscript]
" Figure 3. Main effect plots for tensile shear load. " on page 8, line 298.
" This figure shows the average value of tensile shear load according to the number of levels of each of the six factors: tool rotation speed, welding speed, plunge speed, dwell time, plunge depth, and tool penetration depth. At a given level, it is possible to screen for factors that do not affect TSL with DSD. Tool rotational speed (A) and welding speed (B) are grayed out in the main effects plot in Figure 3 as they have no effect at any given level. Therefore, the tool rotational speed (A) and welding speed (B) are excluded from the process of finding the maximum value of TSL, and the maximum value of the TSL is found as the remaining four factors that affect it. At a given level, the plunge speed is indicative of the curvature, which is optimal. It was found that dwell time and plunge depth had a negative effect, and only the tool penetration depth had a positive effect. The desired result is high tensile shear load, so the maximum TSL is achieved at a plunge speed of 6.5 mm/min, a dwell time of 3.0 s, a plunge depth of 0.0 mm and a tool penetration depth of 1.0 mm." on page 8, line 291~315.
Comment (6) In fig. 6, please indicate the accuracy with which the given planes were obtained. On the basis of how many specific data they were created.
Our response (6) Accordingly, in revised manuscript the explanation of Figure 6 has been modify.
[Modification of the manuscript]
" Figure 6 shows a surface plot for TSL. In order to examine the effect of a given factor, the fixed values ​​of the remaining factors were selected in consideration of the main effect plot in Figure 3. Figure 6(a) shows a three-dimensional surface plot of plunge speed and tool penetration depth for TSL. A dwell time of 5 s and a plunge depth of 0 mm were chosen for the fixed values ​​of the remaining factors. On the surface plot you can find the plunge speed and tool penetration depth that maximizes TSL. Over the entire range of a given plunge speed, TSL increases with increasing tool penetration depth. It can be seen that at a tool penetration depth of 0 mm, TSL increases with increasing plunge speed and decreases after reaching a maximum of about 1,800 N. It can be seen that at a tool penetration depth of 0.5 mm, the TSL increases with increasing plunge speed and decreases after reaching a maximum value of about 2,000 N. It can be seen that at a tool penetration depth of 1 mm, TSL increases with increasing plunge speed and decreases after reaching a maximum value of about 2,200 N. A maximum TSL value of about 2,200 N is achieved at a plunge speed of 7 mm/min and a tool penetration depth of 1.0 mm. Figure 6(b) shows a three-dimensional surface plot of dwell time and tool penetration depth for TSL. A plunge speed of 7 mm/min and a plunge depth of 0 mm were chosen from the main effects plots in Figure 3 as fixed values ​​for the remaining factors. On the surface plot you can find the dwell time and tool penetration depth that maximize the TSL. At a tool penetration depth of 0 mm, the TSL decreases with increasing dwell time. It can be seen that at a tool penetration depth of 0.5 mm, when the dwell time increases, the TSL decreases to the folding point and increases again after the folding point. At a tool penetration depth of 1 mm, the TSL increases with increasing dwell time. At a dwell time of 3 s, the TSL is decreasing with increasing tool penetration depth. At a dwell time of 5 s, as the tool penetration depth increases, the TSL decreases to the folding point and increases again after the folding point. It can be seen that at a dwell time of 7 s, increasing the tool penetration depth increases the TSL. It can be seen that in a given range, a maximum TSL value of about 2,500 N appears at a dwell time of 3 s and a tool penetration depth of 0 mm. Figure 6(c) shows a three-dimensional surface plot of plunge speed and dwell time for TSL. A tool penetration depth of 0.5 mm and a plunge depth of 0 mm were chosen from the main effects plots in Figure 3 as fixed values ​​for the remaining factors. On the surface plot you can find the dwell time and plunge speed that maximize the TSL. Over the entire range of a given plunge speed, TSL decreases with increasing dwell time. Over the entire range of a given dwell time, as the plunge speed increases, the TSL increases, reaching a maximum value and decreasing again after reaching the maximum value. It can be seen that a maximum TSL of about 2,250 N in a given range appears at a dwell time of 5 s and a plunge speed of 3 mm/min. " on page 12, line 514-551.
Comment (7) Regarding microstructural studies, it would be good to carry out more detailed study of the places marked with Hooking (fig. 8 and fig. 9), After correction.
Our response (7) Yes, we are agreed with comments. Thanks for critical review manuscript and we will study on microstructure identification.
[Additional Comment] FINALLY, I ALSO RECOMMEND THAT THE AUTHORS HAVE THEIR MANUSCRIPT CHECKED BY AN ENGLISH LANGUAGE NATIVE.
[Our response] We got our manuscript corrected by a native speaker. We attached the certificate of English editing as follows.
[Our additional response]
- We have given detailed explanations in Figures 3 to 7 of the DOE results to help the reader understanding.
- We presented a method for surface treatment and aluminum oxide removal in the experimental preparation process.
- A clamp that can fix the pipe during the experiment was designed, and the method is registered as a Korean patent (10-2025400). For better understanding, related pictures of fixing the pipe with left/right chucks and clamping are attached.
- The difference between the tensile strength and shear load of the fracture test characteristics was explained and pictures were presented.
- The method for selecting the experimental value of the process variable has been described in detail.
- Using the DSD method, the number of experiments was drastically reduced, making it possible to conduct economical experiments. In this regard, the limitations in which existing researchers could not test multiple process variables at the same time were explained.
Finally, we are grateful to the referees for the comments that helped us improve the quality of our manuscript. The related changes in the manuscript were marked with Blue color. We are reply to the referee’s comments on a point by point basis.
We hope that these revisions are satisfactory and that the revised version will be acceptable for publication in Journal of Materials.
Thank you very much for your work concerning our paper.
Author Response File: Author Response.pdf
Reviewer 3 Report
Please provide the following information:
Line 150 Chapter: Experimental preparation and design methods
- what was the surface preparation method prior to the friction welding process?
- were aluminum oxides removed from the pipe surface prior to the friction welding process, and if so, how?
- was the clamp used during the assembly of elements before the friction welding process, if so, what was its value?
The use of a clamp for materials such as those presented in the article is necessary due to the fact that aluminum has much higher coefficient of thermal conductivity than steel.
In the case of using such low connection speeds as shown in the tests, the lack of a clamp will result in the loss of contact between the elements to be welded.
Table 1, missing letter for silicon symbol (i).
Line 235 Chapter: Results and Discussion
- before carrying out the strength tests, did the authors of the article assess the number and size of internal defects such as porosity and voidness?
- from what angular position the samples were taken for strength tests, please provide the angular values for all 14 variants.
- at what angular positions the macro photos shown in Fig. 9 were taken?
Author Response
PUSAN NATIONAL UNIVERSITY (PNU)
Graduate School of Convergence Science, Pusan National University, busan, Republic of Korea, 46241
TEL: +82.51.510.2361
FAX: +82.51.510.7396
E-mail: [email protected]
24 Sep., 2021
Dear MDPI Materials Editorial Office
Topical Editor
Dear Editor,
We appreciated your efforts in considering the manuscript by providing reviewers comments/suggestions which helped us greatly while revising the manuscript to improve scientific as well as technical quality of the revised manuscript ID: materials-1385885.
According to the reviewers’ comments/suggestions, we carefully have revised the manuscript. We also provided our point-by-point responses to the comments. We are sure that revised version of the manuscript can be of journals standard and as per reviewers’ expectations. The revised text in the new manuscript is marked in blue color.
We would like to receive “the letter of acceptance certification” as soon as possible. Thank you very much for your help in advance.
Sincerely yours,
Head/Professor Myungchang Kang
School of Convergence Science
Pusan National University (PNU)
63 Busandaehak-ro, Geumjeong-gu, Busan, Republic of Korea, Zip: 46241
E-mail: [email protected]
Reviewer #3:
Comment (1) Please provide the following information:
Line 150 Chapter: Experimental preparation and design methods
- what was the surface preparation method prior to the friction welding process?
Our response (1) We greatly appreciate your support and positive comments. accordingly, in revised manuscript suggested the surface treatment has been added.
[Modification of the manuscript]
" A357 cast Al pipe is subjected to T6 heat treatment after casting and surface treatment through shot peening. " on page 5, line 172~173.
Comment (2) were aluminum oxides removed from the pipe surface prior to the friction welding process, and if so, how?Our response (2) We greatly appreciate your support and positive comments.
[Modification of the manuscript]
"Before welding, the aluminum oxide layer of the aluminum alloy was removed with a brush and sandpaper. " on page 5, line 175~176.
Comment (3) was the clamp used during the assembly of elements before the friction welding process, if so, what was its value?
The use of a clamp for materials such as those presented in the article is necessary due to the fact that aluminum has much higher coefficient of thermal conductivity than steel.
In the case of using such low connection speeds as shown in the tests, the lack of a clamp will result in the loss of contact between the elements to be welded.
Our response (3) We greatly appreciate your support and positive comments.
The structure of the clamp we used is described in Korean Patent 10-2025400.
It is designed in a structure that can support the axial force of friction stir by clamping it with a roller on the outside of steel and aluminum in the shape of a pipe.
For reference on the clamp structure and support structure, a picture of the following connections is attached.
Comment (4) Table 1, missing letter for silicon symbol (i).
Our response (4) Authors respect reviewer’s keen observation, chemical composition has been corrected.
[Modification of the manuscript]
" Si " in Table 1.
Comment (5) Line 235 Chapter: Results and Discussion
- before carrying out the strength tests, did the authors of the article assess the number and size of internal defects such as porosity and voidness?
Our response (5) We greatly appreciate your support and positive comments.
In previous experiments, it was difficult to measure the number of voids, and the tendency of voids to occur was identified by C/T imaging. However, in this experiment, since the size of the cavity was large, the measurement of voids by C/T image was not performed. In addition, in this experiment, it was more important to reveal the relationship between plunge depth and tool penetration depth rather than defects. In this study, the number and size of internal defects such as pores and voids could not be evaluated, but will be identified through future research.
Comment (6)
Line 235 Chapter: Results and Discussion
- from what angular position the samples were taken for strength tests, please provide the angular values for all 14 variants.
Our response (6) We greatly appreciate your support and positive comments.
In tensile strength, the angle of fracture can be measured, but in tensile shear load, the angle is difficult to measure because the fracture surface occurs in the direction of tensile force on the contact surface. I am attached a picture of the fracture surface for reference.
Comment (7) Line 235 Chapter: Results and Discussion
- at what angular positions the macro photos shown in Fig. 9 were taken?
Our response (7) We greatly appreciate your support and positive comments. Accordingly, in revised manuscript suggested the surface treatment has been added.
The picture was taken in the direction of 90 degrees perpendicular to the progress direction of the welding part.
[Modification of the manuscript]
" The picture was taken in the direction of 90 degrees perpendicular to the progress direction of the welding part. " on page 15, line 692~693.
[Additional Comment] FINALLY, I ALSO RECOMMEND THAT THE AUTHORS HAVE THEIR MANUSCRIPT CHECKED BY AN ENGLISH LANGUAGE NATIVE.
[Our response] We got our manuscript corrected by a native speaker. We attached the certificate of English editing as follows.
[Our additional response]
- We have given detailed explanations in Figures 3 to 7 of the DOE results to help the reader understanding.
- We present the % error to show the accuracy of the experiment.
- The method for selecting the experimental value of the process variable has been described in detail.
- Using the DSD method, the number of experiments was drastically reduced, making it possible to conduct economical experiments. In this regard, the limitations in which existing researchers could not test multiple process variables at the same time were explained.
Finally, we are grateful to the referees for the comments that helped us improve the quality of our manuscript. The related changes in the manuscript were marked with Blue color. We are reply to the referee’s comments on a point by point basis.
We hope that these revisions are satisfactory and that the revised version will be acceptable for publication in Journal of Materials.
Thank you very much for your work concerning our paper.
Author Response File: Author Response.pdf
Reviewer 4 Report
The comments were attached, thank you!
Comments for author File: Comments.pdf
Author Response
PUSAN NATIONAL UNIVERSITY (PNU)
Graduate School of Convergence Science, Pusan National University, busan, Republic of Korea, 46241
TEL: +82.51.510.2361
FAX: +82.51.510.7396
E-mail: [email protected]
24 Sep., 2021
Dear MDPI Materials Editorial Office
Topical Editor
Dear Editor,
We appreciated your efforts in considering the manuscript by providing reviewers comments/suggestions which helped us greatly while revising the manuscript to improve scientific as well as technical quality of the revised manuscript ID: materials-1385885.
According to the reviewers’ comments/suggestions, we carefully have revised the manuscript. We also provided our point-by-point responses to the comments. We are sure that revised version of the manuscript can be of journals standard and as per reviewers’ expectations. The revised text in the new manuscript is marked in blue color.
We would like to receive “the letter of acceptance certification” as soon as possible. Thank you very much for your help in advance.
Sincerely yours,
Head/Professor Myungchang Kang
School of Convergence Science
Pusan National University (PNU)
63 Busandaehak-ro, Geumjeong-gu, Busan, Republic of Korea, Zip: 46241
E-mail: [email protected]
Reviewer #4:
[General review] This manuscript studied the influence of the process factors on the tensile shear load of the dissimilar cast aluminium-HSS with pipe shape. Some comments should be addressed before moving to next stage:
[Our response] We greatly appreciate the reviewer’s positive evaluation of our manuscript.
Comment (1) Editing error: font size should keep consistent. Please check the paper carefully and avoid such problems.
Our response (1) Authors respect reviewer’s keen observation, size of font has been corrected.
Comment (2) Line 17: the authors claimed that the study was conducted rapidly and inexpensively, could this be more specific or quantified? ‘Inexpensively’ sounds negatively.
Our response (2) Thank you for suggestion, accordingly, in revised manuscript suggested word has been changed.
[Modification of the manuscript]
" economically " on page 1, line 16.
Comment (3) Line 127: the authors claimed that the process factors are difficult to study and leading to the research gap. Could this be explained more specifically, eg. Why these factors are difficult to be experimentally studied?
Our response (3)
It is not difficult to test a small number of process factors, but it is difficult to treat a large number of factors simultaneously. For example, even in the case of a full factorial experiment for 6 factors with a level number of 2, 2^6 =64 experiments are performed. Also, in the case of a full factorial experiment for 6 factors with a level number of 3, 3^6 = 279 experiments should be performed.
Therefore, in order to simultaneously grasp the relative importance of multiple factors, it means that it is difficult to carry out with the existing experimental method.
Comment (4) In table 2, several sets of process factors were compared and studied, the reviewer is curious about the determination of these factor values. Are these values corresponding to the real engineering practice?.
Our response (4) We greatly appreciate the reviewer’s positive evaluation of our manuscript.
In order to simultaneously investigate the effect of process variables affecting tensile shear load, among the factors that can be selected as process variables, plunge speed and dwell time have a great influence in the initial stage, so it was selected from among the few possible values.
For the experimental range for the plunge depth and tool penetration depth, an area with few external defects was selected centered on the optimum spindle speed and welding speed for one tool. Process parameters and their values ​​have been selected and performed from a practical engineering standpoint.
Comment (5) Line 493 to 497: The authors provide the reference for future study and designs, which is good. Just wondering could these recommendations be quantified?
Our response (5) We greatly appreciate the reviewer’s positive evaluation of our manuscript. Thank you for the good suggestion, and I will study quantity of the optimization methods such as the depth of plunge and the depth of tool penetration next time.
Comment (6) The English expressions could be improved, probably by native speakers.
Our response (6) We got our manuscript corrected by a native speaker. We attached the certificate of English editing as follows.
[Our additional response]
- We have given detailed explanations in Figures 3 to 7 of the DOE results to help the reader understanding.
- We present the % error to show the accuracy of the experiment.
- We presented a method for surface treatment and aluminum oxide removal in the experimental preparation process.
- A clamp that can fix the pipe during the experiment was designed, and the method is registered as a Korean patent (10-2025400). For better understanding, related pictures of fixing the pipe with left/right chucks and clamping are attached.
- The difference between the tensile strength and shear load of the fracture test characteristics was explained and pictures were presented.
Finally, we are grateful to the referees for the comments that helped us improve the quality of our manuscript. The related changes in the manuscript were marked with Blue color. We are reply to the referee’s comments on a point by point basis.
We hope that these revisions are satisfactory and that the revised version will be acceptable for publication in Journal of Materials.
Thank you very much for your work concerning our paper.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
I am ok with the authors' response
Reviewer 4 Report
Can be accepted.
