Effect of Mg Addition on Microstructure and Sacrificial Anode Protection Performance of Hot Dip Al-5Zn-4Si-xMg Coating

Round 1

Reviewer 1 Report

 

Dear Authors,

The article submitted to me for review, entitled " Effect of Mg Addition on Microstructure and Sacrificial Anode Protection Performance of Hot Dip Al-5Zn-4Si-xMg Coating", presents the results of research on the effect of Mg addition on the microstructure and sacrificial anode protection performance of hot-dip Al-5Zn-4Si-xMg coating. The authors describe the research in a substantive correct manner, analyze the obtained results, and draw the right conclusions. The content of the article may be useful in a development of the technology to manufacture corrosion protection. The subject matter is interesting and important, especially due to the increasing attention given to the environmental and social sustainability issues of production processes. I rate the reviewed article very positively in terms of the scope of research and the essence of the information provided. In order to emphasise the utilitarian nature of the tests performed, I suggest an indication of the industrial area of applicability of the obtained results in the description. Authors must check on terminology, uniformity of language, spelling, etc. The following corrections are necessary:

- Figure 1 should be corrected. The description is illegible.

- Specify the parameters at which X-Ray Diffraction tests were performed.

I congratulate the authors of the high level of research and to encourage further work undertaken on the subject.

I accept the article for publication after making minor corrections.

 

Yours sincerely,

Artur Czupryński

 

 

Author Response

Please see the attachment.

Reviewer 2 Report

The paper reports the effect of Mg addition on the hot-dip Al-5Zn-4Si-xMg coating. There are several critical aspects to be considered before considering for publication.

a)      The quality of Figure 1 needs to be improved. The writings are not readable. Correctly label the X-axis as wt.% Mg and Y-axis as T(°C).

b)     In the section describing the effect of addition of Mg using Fact Sage software, temperatures should also be mentioned and discussed on how this helps in designing the present study.

c)      Details pertaining to the hot dip process is not clearly elaborated, such as the bath temperature, dipping time, how the coating thickness was controlled etc.

d)     Figure 2 and Figure 5 – How the observed phases or elements are confirmed? For eg: it has been reported that Zn, MgZn2, Mg2Si are present in microstructure, how was this confirmed, is it based on morphology?

e)     Fig. 4 is not clear and it is recommended to provide a high quality image. It is suggested to mention the hkl planes and Bragg angle (with reference to the database) in text for a better understanding. The peaks of SiO2 and Al2O3 is not clear. Also, a magnified view of peak splitting at around 65° needs to be provided, to display the clear distinction between Al and MgAl2O4 peaks.

f)       In Fig 5, it is suggested to clearly indicate which is the topmost surface and which is the substrate material surface. What was the thickness of the coating? In Fig. 5 how was the imaging conducted, in SE mode or BSE mode? It can be observed that (a, c) and (b, d) shows difference in contrast.

g)      It has been reported that electrochemical impedance spectroscopy analysis is conducted. However the results are missing.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

The presented manuscript seems to be interesting for readers of the Coatings journal, it is written in a good manner and suits the requirements of the journal. It can be accepted for publication after minor corrections listed below. 

- Abbreviation/ acronyms, should all be defined at their first occurrence in the manuscript

- The "Abstract" section should contain the main achievements of research not general discussion. Re-organization of abstract is needed.

- The novelty of work at the end of manuscript “introduction” is not sufficient and should be explained more.

- References 3 and 18 are the same and should be corrected.

- References 2 and 17 are the same and should be corrected.

- The authors have mentioned in the text that: “According to the research of Chen Dong et al., the addition of Mg to Al-Zn-Si alloy can make the self-corrosion potential shift positively, increase the corrosion resistance of the alloy coating, and thus improve its corrosion resistance [55] . Zhong et al. [56] believed...”. “The anode is the dissolution of magnesium-rich, zinc-rich, and aluminum-rich phases [53].”

Reference numbers 53, 55 and 56 are not available in the reference list

- The order of references should be followed: [12-13] comes before [10-11]. Also references [29] and [30] came before [23]. Please check and correct.

- The quality of Figure 1 is low. Please check and correct.

- The basis for choosing the percentage of magnesium in the coating should be given.

- It is suggested to bring Bode and phase curves to better investigate the corrosion behavior of the coating

-The optimum condition in the fabrication operation needs to be determined. The authors need to pay attention in the revision stage.

- In the "Conclusion" section, the authors should present more quantitative data as the main results of the research study rather than just some qualitative data.

- Literature review is not sufficient and authors must review and cite more papers in the field of “Modeling thickness and properties of coatings” and especially newly published ones. Doing this, review and citing the following refs could be helpful: Journal of Intelligent & Fuzzy Systems 26, no. 5 (2014): 2229-2237., Neural Computing and Applications 24, no. 3-4 (2014): 685-694.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The authors have revised in response to the revision comments and the manuscript shall be considered for publication. Kindly correct the SEM figure captions for Figure 2, 3, 7 change as "Scanning electron microscopy image (in Secondary Electron imaging mode) ..." and Figure 5  as "Cross-sectional scanning electron microscopy image (in Backscattered Electron imaging mode) ..."

 

Reviewer 3 Report

The revised paper might be accepted for publication.