Effect of Ultrasonic Impact on the Organization and Friction Wear Performance of AZ31B Magnesium Alloy Micro-Arc Oxidation Composite Coating

Round 1

Reviewer 1 Report

coatings-2435774

In this manuscript, the authors provide a comprehensive study regarding “Effect of Ultrasonic Impact on the Organization and Friction Wear Performance of Micro-Arc Oxidation Composite Coating”. It is eye-catching and exciting to a researcher in this field. However, some corrections and explanations must be done previous to publish the paper in the Coatings. Some of my comments and questions on this manuscript are as follows:

 

1-  In the abstract, you need to focus more on quantitative information, not qualitative ones. In addition the title could be modified.

2- The authors did not explain the novelty and significance of their work in the introduction section. Moreover, this section is not cohesive. Indeed, this section is intended to "convey the core findings of the paper," i.e., reflect the best novelty of this paper in a concise form. The authors shall show the work's best novelty, such as how your research. advances the state-of-the-art of the topic/area and /or how much better is your work compared with peer researchers on the same or similar topics. At the end of this section, the main objective of this study must be mentioned.

3- The advantages of the UI-MAO composite coating should be further highlighted in the introduction section. IN addition, the quality of all figures should be improved.

4- The author stated that “coatings prepared using different UI process times:(a) 0 min, (b) 5 min, (c) 10 min,(d) 15 min”. In this respect, more information regarding the deposition time must be given. You have to clarify the reasons for selecting these deposition times (0 min, 5 min, 10 min, 15 min)? You have to clarify the reasons for this deposition time. You have to add a reference for that or explain how you got this deposition time as optimal ones.

5- Well-organized discussion should be added regarding the wear mechanism of UI process and UI-MAO composite coatings, combined with recent works and scientific progress in the area. Provide a more in-depth discussion.

6- Integrity, thickness and uniformity of the UI process and UI-MAO composite coatings are mentioned as an essential factor for great coating. In this regard, did you measure the adhesive strength of the UI process and UI-MAO composite coatings layer with substrate? In addition, all sections and subsections including introduction require numbering.

7- The relationship between MgO and Mg2SiO4 phases and microhardness and wear behavior should be further highlighted?

8- In conclusion, specify the application of this work clearly, and also provide the application of this particular material with key features in one or two sentences.

9- Some references about MAO coating might be useful for this article: Coatings 2021, 11 (7), 747; Surface & Coatings Technology 334 (2018) 450–460. In addition, surprisingly small references to the Coatings in the literature despite the large relevant literature there. This should be improved. There are several important papers in recent literature.

Author Response

please see the attachment. Thanks in advance.

Author Response File: Author Response.pdf

Reviewer 2 Report

1. In section 3.1, incorrect reference to figure. Should be 2 a, b, c, d, but is 1 a, b, c, d.

2. Incorrect numbering of chapters, chapter 3.5 is followed by chapter 3.7, chapter 3.6 is missing.

3 Fig. 9 lacks description (e).

4. Poorly legible descriptions on most figures.

5. Section 2.1 lacks information on how the substrate material (AZ31B magnesium alloy) from which the test specimens were made was prepared. According to the reviewer, the level of adhesion of the coating is influenced by the surface morphology of the sample. I would ask the authors of the paper to provide Ra and Rz data for the samples tested in the article.

6. There is no reference of the results obtained to other methods of applying composite layers to magnesium alloys.

7. It is evident from the work that the wear resistance increases with increasing coating thickness. The wear time of a coating with a greater thickness increases. It is likely that with further surface treatment (more than 15 minutes) there will be an increase in coating thickness and wear resistance will increase. What is missing from the results of the paper is a more complete evaluation of the effect of the coating application method on other important characteristics of structural materials, e.g. corrosion resistance, strength properties, etc. In order to improve the quality of the article, it would be advisable to present the test results for a specific product in relation to the specification requirements for that product.

8. In the reviewer's opinion, the authors should also carry out tests on magnesium alloy with a composite layer applied under exemplary operating conditions.

9. The final conclusions result from the conducted research, however, in the conclusions the authors did not refer to the application value of the presented research.

Author Response

Please see the attachment

Author Response File: Author Response.pdf