Effect of the Anodizing Temperature on Microstructure and Tribological Properties of 6061 Aluminum Alloy Anodic Oxide Films
Round 1
Reviewer 1 Report
The present work presents the main features of the microstructure of oxide films (AAO) of aluminum alloy 6061 depending on the controlled change in the temperature of the electrolyte. Overall, the scientific quality of the submitted manuscript is fine. The discussions based on the experimental results are sound. Several minor concerns are proposed herein for revision.
- The relevance, motivation of the study and the current status of the research need to be better confirmed. Among the first 15 references, only 5 are younger than 5 years old.
- Line 33. It is absolutely important to mention aluminum oxide here, which has a tremendous value and many applications in fusion technology (Kotomin, E.A. et al; Kinetics of F center annealing and colloid formation in Al2O3. Nucl. Instrum. Methods Phys. Res. Sect. B Beam Interact. Mater. At.2016, 374, 107–110 ; Averback, R.S.; Ehrhart, P.; Popov, A.I.; Sambeek, A.V. Defects in ion implanted and electron irradiated MgO and Al2O3. Radiat. Eff. Defects Solids 1995, 136, 169–173.)
- Lines 54, and 56. Sentences need supporting references.
- Line 167. Can you comment and estimate the size of the oxygen bubbles?
- Can you comment on how the evolution of pores occurs over time. What other aging process is taking place at this moment?
- Please check/complete the following references: 3, 14, 15, 21.
Author Response
Point 1: The relevance, motivation of the study and the current status of the research need to be better confirmed. Among the first 15 references, only 5 are younger than 5 years old.
Response 1: Several references have been added and identified.
Point 2: Line 33. It is absolutely important to mention aluminum oxide here, which has a tremendous value and many applications in fusion technology (Kotomin, E.A. et al; Kinetics of F center annealing and colloid formation in Al2O3. Nucl. Instrum. Methods Phys. Res. Sect. B Beam Interact. Mater. At.2016, 374, 107–110 ; Averback, R.S.; Ehrhart, P.; Popov, A.I.; Sambeek, A.V. Defects in ion implanted and electron irradiated MgO and Al2O3. Radiat. Eff. Defects Solids 1995, 136, 169–173.)
Response 2: It has been added as Reference 3 and 4.
Point 3: Lines 54, and 56. Sentences need supporting references.
Response 3: It has been added as Reference 18-20, and mentioned on the Line 56-66.
Point 4: Line 167. Can you comment and estimate the size of the oxygen bubbles?
Response 4: The current detection cannot accurately measure the diameter of the bubble, but we will gradually improve this part of work in the future work.
Point 5: Can you comment on how the evolution of pores occurs over time. What other aging process is taking place at this moment?
Response 5: The formation of pores in the oxide layer is the result of a combination of multiple factors, each of which is very important for the formation of pores, and the porous characteristics formed by the combined force of multiple factors, so it is difficult to accurately explain the evolution of pores.
Point 6: Please check/complete the following references: 3, 14, 15, 21
Response 6: It has been completed.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Dear Authors,
the manuscript presented for evaluation is a very interesting approach to the problem of surface durability of materials. The job is generally good although it needs improvement in several respects:
1. there are editing errors in the work, e.g. lines: 36, 41, 43, 46, 48 etc. are there errors in writing units ((5 ℃, 15 ℃, and 25 ℃) using 160g / L) should be the distance between the unit.
2.Introduction is too poor, more similar work on aluminum alloys could be included here.
3. Fig. 1. Descriptions in the figures are poorly visible, I suggest replacing the black font color with white.
4. Fig. 3. and Fig. 4., too large descriptions of the axes in the drawings.
5. Fig 6. I propose to enlarge this drawing because it is illegible, especially the axes of the graphs.
6. I also believe that the literature review should be strengthened, there is a very poor literature of only 24 items. I propose to add, for example, the following publications to the work:
DOI: https://doi.org/10.12913/22998624/129951
https://doi.org/10.3390/ma15010288
https://doi.org/10.3390/ma14030619
https://doi.org/10.3390/ma14010175
https://doi.org/10.3390/ma14216503
These works are the latest reports and will allow the authors to strengthen the level of the manuscript.
Thank you.
Author Response
Point 1: there are editing errors in the work, e.g. lines: 36, 41, 43, 46, 48 etc. are there errors in writing units ((5 ℃, 15 ℃, and 25 ℃) using 160g / L) should be the distance between the unit.
Response 1: It has been modified.
Point 2: Introduction is too poor, more similar work on aluminum alloys could be included here.
Response 2: It has been added some aluminum alloy related work.
Point 3: Fig. 1. Descriptions in the figures are poorly visible, I suggest replacing the black font color with white.
Response 3: Figure 1 has been modified and replaced.
Point 4: Fig. 3. and Fig. 4., too large descriptions of the axes in the drawings.
Response 4: Figure 3 and Figure 4 have been modified and replaced.
Point 5: Fig 6. I propose to enlarge this drawing because it is illegible, especially the axes of the graphs.
Response 5: Figure 6 has been modified and replaced.
Point 6: I also believe that the literature review should be strengthened, there is a very poor literature of only 24 items. I propose to add.
Response 6: Related references have been added.
Author Response File: 
Author Response.docx
Reviewer 3 Report
The paper is devoted to an investigation of effect of the anodizing temperature on microstructure and tribological properties of 6061 aluminium alloy anodic oxide films. The topic fits within the scope of the Journal.
The article is correctly written, detailed and logically structured. The article could be interesting for the general auditory of Coatings Journal.
The reviewer suggests minor revision:
- In the abstract and in point 2.3. (Structure and composition and anodic films) - it should be noted that with the use of the X-ray diffractometer no microstructure or morphology can be observed! Please correct this statement.
- In point 3. Results line 207 "presence of the aluminum element". Please provide the correct name: aluminum phase
- In Figure 3, the Al phase is marked as matrix. These are the substrate peaks, this is the aluminum phase. Please enter this name correctly.
Author Response
Point 1: In the abstract and in point 2.3. (Structure and composition and anodic films) - it should be noted that with the use of the X-ray diffractometer no microstructure or morphology can be observed! Please correct this statement.
Response 1: It has been modified.
Point 2: In point 3. Results line 207 "presence of the aluminum element". Please provide the correct name: aluminum phase
Response 2: It has been modified.
Point 3: In Figure 3, the Al phase is marked as matrix. These are the substrate peaks, this is the aluminum phase. Please enter this name correctly.
Response 3: Figure 3 has been modified and replaced
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
the authors constructively took into account all the comments and recommendations; as a result, the manuscript has been significantly improved and can be recommended for publication
