Impact of Corrosion on the Degradation of the Mechanical Properties of 2195 and 2297 Al Alloys in the Marine Environment

Round 1

Reviewer 1 Report

The manuscript studies corrosion behavior and corrosion-induced mechanical properties degradation of 2xxx series aluminum alloys in the marine environment. 

1- The manuscript needs an extensive style and language revision. The manuscript should be checked and revised by an English native speaker who is an expert in the field.

2- The scale bars of the micrographs are not according to the usual format of the journal.

3- The introduction is not enough convincing and should be improved to show the motivation for this study. Also, please add this references about the effect of size of the particles and heat treatment and also, clarify this effect in your current results:

https://doi.org/10.1016/j.msea.2020.139850

4- There is no observation of the formation of the aluminum hydroxide and the thickness. Please add the observations or add some references.

5- In the methodology section, it is not clear when the mechanical testing was done. It seems that it should be done after the exposure time. However, it should be clearly explained in the methodology.

6- There is not enough discussion about mechanical degradation. The discussion is shallow and I could not see the main mechanism. Please extend the discussion.

7- The fracture surface is not enough related to the mechanical degradation mechanisms and explanation is not enough. Please magnify the features on the fracture surface and explain the relations to the particles and compare this behavior in two alloys.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Hulin Wu et al., elaborated the manuscript “Corrosion-behavior and Corrosion-induced Mechanical Properties Degradation of 2xxx Series Aluminum Alloys in Marine Environment”. Comprehensive work implying the corrosion behavior of 2xxx type Al alloys were presented, authors addressing a common issue impacting the marine domain. Overall, I find this article well-structured and backed up by sufficient experimental data (over 12 months of data), while authors should address several of the following remarks:

 -          English should be revised; Abbreviations should be included in the abstract and in the manuscript;

-          Authors should take into consideration the publisher guidelines; For instance, affiliations should include the department;

-          Keywords should include the studied materials/configurations;

-          Include manufacturer information (country etc.) for the applied  instruments and materials, as imposed by the publisher;

-          Alloys were exposed to the marine atmosphere over a year; This controlled experiment should in-detailed be described;

-          Table 1 and 2 could be merged in one single table;

-          Include in fig.1 the xy coordinates for plane orientation;

-        include in the “materials and methods” the applied methods (EDX, SEM etc) and their working parameters;

-          What was the measuring magnification applied in fig. 2 and 3? Seems as overview, low magnification scale; however authors should include a higher magnification images since the scope of this study is to track and trace the erosion pit and depth; Figure 5 are more properly addressed for this manner;

-          Authors presents in figure 2, 3 the microstructural characteristics observed by SEM, however authors states: as can be seen from the more in-depth corrosion morphology in Figures 2 (b, c, d) and Figure 3 (a, b, c, d); Hard to see it as presented in the manuscript.  Authors should comment how a surface investigation instrument could output information regarding a “in-depth” / “in volume” particularity? Reference 27 is good but not applicable in the presented figures. Did authors considered to investigate possible “in volume” defects by X-ray computed tomography?

-          In figure 3, scales are out of the image;

-          In figure 4, the caption is incorrect: “EDS results obtained for the regions shown in figure 2(c) andfigure 4(c), respectively 119 (wt%). of 2297-T8 and 2195-T8.” The referenced figure is 3(c);

-          Figure 4 is not referenced in the manuscript;

-          “To investigate the corrosion rate, which is essential in corrosion behavior.”, rephrase; The determination of the pits diameter should be more clearer explained;

-          Lacking information regarding the “uniaxial tensile mean yield stress and mean tensile strength”, please include in the “materials and methods” section;

-          Figure 10 has a good contrast; Authors should consider it as reference for fig. 8 and 9;

-          Figure 11.b, the scale bar is not visible;

-          Figure 11 and 12 were taken by SEM? In cross-section? Please make it more clear in the figure caption;

-          In conclusion, authors states: “the corrosion products on the surface of 2297-T8 become more and more serious….”; Authors should rewrite adapt the used words more adapted to a manuscript;

-          Authors should add the findings resulted from EDS measurements in the Conclusion section;

I recommend the acceptance of the manuscript after a major revision and implementing the mentioned observations;

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

The study “Corrosion-behavior and Corrosion-induced Mechanical Properties Degradation of 2xxx Series Aluminum Alloys in Marine Environment” is a interesting peace of work in the field of corrosion behavior of aluminum based alloys. The research is well and logically performed. I can recommend this study for publication after the following revisions:

Line 34: “increasing the elastic elasticity of the alloy” elastic elasticity?

Line 43: what is microstructural composition? Do authors mean the phase composition?

In figure 4, 6, 9 the graphs should be given under the letters (a), (b) etc.

In Figure 9 the average tensile modulus is given in the axis but in the caption is “tensile strength”. These should be uniform.

Could authors explain the reason of the increase in UTS after 6 months (Figure 9). The increase is higher than the error bar.

The conclusion 2 is not clear for understanding. I suggest there are some technical mistakes.

In addition I recommend the authors to add the quantitative characteristics in conclusion section. Anyway it seems superficial in present state.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The current version is much better than the previous one. I recommend publication with a minor revision in style and the language of the manuscript.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Based on the comments and observations, the authors improved the manuscript significantly. I propose the publication of the manuscript in the present form.

Author Response

Thank you for your review and acceptance.

Reviewer 3 Report

The paper can be accepted in present state

Author Response

Thank you for your review and acceptance.