Correlation between Microstructures and Tensile Properties in Friction Stir Welding Joint of Zn-Modified 5083 Al Alloy

Round 1

Reviewer 1 Report

In my opinion, the article still requires a lot of work.

1. The authors cited in the references only two publications from the last five years (6%) References should be updated.

2. The method used to determine the chemical composition (table 1) of the alloys should be specified.

3. Some of the research methods should be described in more detail. The manufacturer, description and working parameters of the SEM, EBSD, OM applied should be given, i.e. in the case of SEM acceleration voltage, work distance. Similarly for all research method more details should be provided.

4. The abbreviation SSRT should be expanded on line 97.

5. The abbreviations in Figure 3 are inconsistent with the description in the text (lines 123 and 124).

6. In table 2, the zinc content is 0.24% and in the text 0.25%. This needs to be corrected.

7. In the discussion and conclusions, the authors refer to the appropriate microstructure and phase composition of the alloy. However, no results were presented, e.g. in the form of XRD phase analysis or chemical composition analysis. At the same time, the microstructure of the material was not properly presented. The photos from the optical microscope (Figs. 5, 6, 7) are of very poor quality. They should be corrected or images from a scanning microscope should be added. If the authors do not add this, the text of the manuscript should be re-edited.

If the comments were thoroughly considered by the authors, I would be willing to review this paper again.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The authors attempted to determine the relationship between Microstructures and Stress Corrosion Behavior in Friction Stir Welding Joint of Zn-modified 5083 Al alloy. The article has good potential, but before publication it is necessary to respond to comments and increase the discussion.

It is not clear what conclusions the authors came to, since there are no results of corrosion itself. Also, microstructural studies are not enough, since the weak discussion talks about the dislocation structure. The authors should discuss the results obtained.

1. Do Authors need Fig. 1?

2. How are samples prepared for EBSD?

3. Fig. 2 are practically the same, how necessary are they?

4. In fig. 3 what does Re-side, HGZ, TMCZ, AD mean? Explain please.

5. An error should be indicated in tables 2 and 3. How were the specimens cut for testing mechanical properties?

6. There is not a word about microhardness testing in the methodology.

7. Why is the welding speed chosen: 300 mm/min?

8. What is the depth of the FSW and what is the shape of the tool?

9. How was the grain size calculated? Please provide measurement error and data for all zones. The data is only for one speed, it is necessary to compare all modes, as in the rest of the experiments.

10. To save space, Authors can combine fig. 5-8 or 6-8. Why was EBSD done if grain misorientation is not given?

11. Typo in fig. 9

12. Line 233: a beta-phase is discussed, but there is no data confirming its presence.

Author Response

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Round 2

Reviewer 1 Report

I accept in present form

Author Response

Dear Reviewer,

Thank you for your significant input on this manuscript.

Kind Regards

Zhixiong Zhu

Reviewer 2 Report

The authors have significantly improved the article. A few questions and clarifications remain.

1. The grain size according to EBSD analysis is determined very easily, it seems to me that these data should be included in the article.

2. Tensile specimens (figs. 2 and 3) do not need to be given, it may be worth describing the dimensions in the text. Choice of authors and editors.

3. Most important. The title of the article says of microstructural  and corrosion studies. However, there are no stress corrosion resistance tests in the article. The title of the article should be changed or the authors should add corrosion studies.

Author Response

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Author Response File: Author Response.pdf