Effect of Ni Doping on the Embrittlement of Liquid Zinc at Σ5 Fe Austenite Grain Boundary

Round 1

Reviewer 1 Report

The paper is really good and well fits the standard of Metals journal.

I think the paper can be accepted after the following minor revisions

1. Line 31: I suggest to add the following MDPI reference:

    A. Di Schino, Metals, 10(3), 327, 2020

2. Figure 1: please improve the quality of the picture

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The study "Effect of Ni doping on the embrittlement of liquid zinc at Σ5 Fe austenite grain boundary" is interesting and beneficial. The manuscript includes most of the essentials that a study of this type should contain.

The authors basically count on an isolated foreign Zn atom surrounded by iron atoms. Does this correspond to reality? Is the distribution of the metal atoms discussed in the work really purely random, are they really monatomic impurities? Isn't the fact that more Zn atoms or Zn clusters appear in the structure?

Wouldn't another "impurity" than Ni conversely improve the properties of iron and reduce the negative impact of Zn? Have such more calculations been made? And what about the presence of some non-metal?

The authors are asked to state whether it is really relevant and possible that the calculation was performed with such accuracy (including input parameters) that it makes scientific sense to present energy with such accuracy, like e.g. −305.12848955 eV or −305.12848952 eV. The number of significant digits here is 11, which is staggering. Many significant physical or chemical constants are not determined with such precision.

Please use a consistent number of decimal places or valid digits. The notation "... −4 eV and 1.5 eV ..." is certainly scientifically incorrect and should be written as "... −4.0 eV and 1.5 eV ..." (Page 14, Line 381).

The scales on Fig. 12, 13, 14, 15, and 17 should be finer, the division of 0 and 0.1 is not very clear and user-friendly. In addition, it should be "0.0 and 0.1" and not "0 and 0.1".

Minor comments (especially of a typographic nature):

• Page 1, Line 28/29: Please use space between word and reference, e.g. "... processes[1–4]." should be written as "... processes [1–4].". This applies to the entire document.
• Page 2, Line 49: The abbreviation "GB" should be introduced on the first place of appearance which is Page 1, Line 35.
• Page 3, Line 115: Please use typographically correct symbol for °C.
• Page 3, Line 115: The Hyphen symbol (-) is used in the manuscript instead of the correct Minus Sign.
• Page 7, Figure 6: Please add dot at the end of "a.u", "a.u." is correct.
• Page 7, Figure 6: Please check the label of Fig. 6 and correct it "... and Ni:.".
• Page 8, Line 245: Please check the red text.
• Page 9, Figure 9: Please unify the captions of the figures. Sometimes they end with a dot, other times they do not.

According to Crossref Similarity Check, the document compliance rate is 22 %. A document of compliance is attached.

Comments for author File: Comments.pdf

Author Response

Please see  the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

This is a very interesting work, in which the authors performed first-principle computational tensile tests on Zn-embrittled austenite grain boundaries. They analyzed the effects produced by introducing Zn and Zn-Ni elements using Σ5 [001] (210) 53.6° face-centered cubic (fcc) Fe symmetrically tilted grain boundary model and the corresponding doped grain boundary models. And, by means of the determination of the changes in atomic and electronic structures caused by grain boundary doping, they proposed a mechanism for the liquid Zn-induced embrittlement phenomena. Also, the paper is well structured and organized, and provides information of interest to the readers of Metals. Therefore, I recommend the acceptance without any modification.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf