Cracking Behavior of Atmospheric Plasma-Sprayed 8YSZ Thermal Barrier Coatings during Thermal Shock Test

Round 1

Reviewer 1 Report

The authors have prepared plasma-sprayed TBCs using two kinds of agglomerated sintered Yttria-stabilized zirconia (YSZ)  powders with different particle sizes. The mechanical properties and crack propagation behavior of the coatings during the whole life cycle were studied by thermal shock test. The effect of YSZ powder particle size on the cracking behavior of the TBCs during thermal shock was analyzed using the results of pore structure, mechanical properties, and stress state of the coatings. 

This study is relevant to the coatings journal.

The applied methodology and discussions are interesting and useful for the learners.

Moreover, the quality of the manuscript can be enhanced effectively by including the following points: 

1. Add the complete form of  YSZ in Title and the Abstract. Also, why 8YSZ is written in the title? Please elaborate on it in the abstract. 

2.  Add more literature studies in the Introduction section. Also, the specific literature gap is not addressed. It needs to be critically studied and summarized in the last part of the Introduction. 

3. Also, Submit a graphical abstract that shows the overall view of the research contents.

4. Add the stepwise coating preparation methodology using schematic diagrams. Also, add the real images of samples in the Materials and Methods section. 

5. Section 2.2 heading ". Coating property evaluation and characterization" need to be corrected "Evaluation of Coating properties and characterizations". Also, give the details of properties and characterizations. 

6. "From the microstructure of the coating, it can be seen that the pores in the coating prepared by fine 159 YSZ powder are finer than those of coarse YSZ powder" Why? 

7. Explain the physics of the following comments "The fracture toughness of the coating prepared by two kinds of YSZ powder both increases with the increase of thermal shock time, and the fracture  toughness of the coating prepared by fine particle size YSZ is always higher than that of  the coating prepared by coarse YSZ powder during thermal shock"

8. Add the reference "The evolution of crack density is similar to that found by Jordan et al."

9. "as the thermal shock cycle continues to increase, the crack density in the coating decreases gradually" Why?

10. "The crack density and average length of the coating prepared by coarse YSZ powder did not change significantly after 300 thermal shocks" Why?

11. How do you check the uniformity of coatings? Explain it.

12. The conclusions are well presented. Only it is required to add future scope so that readers may apply it in their research.

13. All Figures have good clarity. 

Overall, the work included in this manuscript is good for publication. 

My recommendation is a Major Revision. 

 

 

 

 

Author Response

Please see the attachment.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper "Cracking behavior of atmospheric plasma-sprayed 8YSZ thermal barrier coatings during thermal shock test" is suitable for publication in Coatings Journal.

The authors have performed very interesting research in the field of thermal coatings.

Line 32. The authors can add some applications that can be coated and improved with this technique. Recommended reference: 10.3390/coatings10121186.

Line 120: Please add the SEM parameters.

After SEM analysis, the authors should add some XRD analysis in order to identify the specific compounds of the coatings.

Add to figures 8 and 9 the standard deviation values.

Summarize the conclusions and add extra two points.

 

The rest is fine.

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors have made all the required corrections. Now in its current form, it can be accepted.