Study of Hydrogen-Induced Plastic Damage Response of 7085-T7651 High-Strength Aluminum Alloy
Round 1
Reviewer 1 Report
The article of the team of authors is devoted to the study of the behavior of high-strength aluminum alloy 7085 under the influence of hydrogen and hydrogen-induced plastic damage. In general, the presented work has a certain level of novelty and practical significance, and the obtained dependences can be further used in practice in similar developments. The article has a good structure, as well as a large amount of illustrative material, which quite well reflects the presented results and the obtained dependencies. In general, the article corresponds to the subject of the journal, and can also be accepted for publication after the authors answer all the questions.
1. In the abstract, the authors should provide more details about the research being conducted and its novelty.
2. From the presented TEM and SEM images, it is not clear how exactly the penetration depth of hydrogen was determined, as well as its concentration near the boundaries and cracks.
3. The authors should describe in more detail how exactly the depth distribution was obtained, and also determine the maximum depth of hydrogen penetration into the surface layer. The assertion that there was more hydrogen near cracks should also be confirmed by calculations or analytical data.
4. The results of microhardness require additional analysis, the authors should explain what caused such a strong difference in the values of hardness in depth, as well as the presence of local maxima.
5. As additional confirmation of structural changes, the authors should provide X-ray diffraction data.
6. In conclusion, the authors should reflect further plans for research.
7. For all observed experimentally obtained parameters, the values of standard deviations should be given.
Author Response
Dear Reviewer,
We thank the reviewers for their critical reading of the manuscript. The suggestions are helpful for us to improve the manuscript. Our responses to the reviewers’ comments are listed in the following and all the modifications are highlighted using red font in the revised manuscript.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The influence of hydrogen on the mechnical properties and the fracture mechanism on the fracture surface of 7085 Al alloy was investigated. The role of the transcrystalline regions on the fracture surface is not yet clearly shown, which is probably also due to the small image sections. Between 10 and 20 days of loading, there seems to be a higher proportion of transcrystalline regions.
Please check your references and the statements in the last section. The changing fracture morphologie from dimples (transgranular) to intergranular is typical for BBC steel an not for FCC materials. The Last reference (Song et al) does not show Mg-H complexes on the grain boundaries. The authors only conlude that there are H and Mg on the grain boundaries which weaken the grain boundaries.
Author Response
please see attachment
Author Response File: Author Response.pdf
Reviewer 3 Report
My comments for „The Study of Hydrogen-Induced Plastic Damage Response On 7085 High Strength Aluminum Alloy”, are shown below. The manuscript respects the journal’s template, the information is well-arranged. The article can be published after minor changes.
1. Please insert the superscript for each address, that corresponds to the authors;
2. Regarding the used material: is it “7085 high-strength aluminum alloy” or “7085-T7651 aluminum alloy”? Please declare the same name in the manuscript.
3. Section 2.2 Pre-charge hydrogen: after the hydrogen charging process, have you seen surface changes in the used material, e.g. brittles, bubbles, or small nanostructures?
4. What about the oxide layer from the material surface? How will influence the diffusivity of hydrogen inside the bulk material? Also, what about hydrogen storage/release in /and from the material? Usually, after the hydrogen is stored inside the material, will start to migrate to the material's surface in a certain amount of time.
Author Response
Dear Reviewer,
We thank the reviewers for their critical reading of the manuscript. The suggestions are helpful for us to improve the manuscript. Our responses to the reviewers’ comments are listed in the following and all the modifications are highlighted using red font in the revised manuscript.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors answered all the reviewer's questions and made corrections according to these comments, the article has become much better and can be accepted for publication.
