Effect of Nb Content on Phase Transformation and Comprehensive Properties of TiNb Alloy Coating

Round 1

Reviewer 1 Report

In this study, the phase transformation, mechanical properties, corrosion resistance, and biocompatibility of TiNb alloy coating with high Nb content were studied by laser cladding. The results obtained in this study show that the surface of the laser cladding TiNb alloy coating is flat without obvious defects or cracks. The rapid heating and cooling process and high Nb element promote the formation of β phase in the coating, and high Nb content promotes the formation of a single β phase alloy. Furthermore, by adding different Nb content, the phase composition, wear resistance, corrosion resistance, and biocompatibility of laser cladding TiNb alloy coatings can be changed, and the alloy coating with the required properties can be obtained, which has great potential in the application of laser cladding biomedical TiNb alloy coating. The motivation of the work and the approach adopted are well. The manuscript is publishable after the below mentioned questions/comments are addressed.

Comment:

 

1) What is the chemical reason for the observation of contact angles between the coating and TC4 surface?

2) It would be great if you determine the peaks related to α and β phases in the XRD spectrum. Please see the following reference:

Metals 2022, 12(9), 1528; https://doi.org/10.3390/met12091528

3) What is the effect of different Nb contents on the stress-strain curves of the alloy?

 

Author Response

请参阅附件。

Author Response File: Author Response.doc

Reviewer 2 Report

Effect of Nb content on phase transformation and comprehensive properties of TiNb alloy coating

The paper presented a series of experimental studies on the TiNb alloy coating.

The concern is directed to mechanical properties, corrosion resistance, and biocompatibility due to high Nb content. This is exciting work, but several revisions are demanded to increase the readability, as clarity in writing and paper structure are vital.

1. Abstract is required to be rewritten. Ensure it includes a short intro, research gap, aim, short method, and short result.

2. Why only Biocompatibility is put in keywords? Meanwhile, mechanical properties and corrosion resistance are the main discussions in this work.

3. Introduction is too long. This section should only introduce the problem and research gap, the proposed solution, and what will be conducted in this research to solve such problems.

4. Milestone study must be given in a new section, Literature Review. State-of-the-art is not highlighted as there is no comparison of previous works.

5. Each material or compound must be clarified in its source, i.e., manufacturer, city, and country. Also, all testing apparatus must be clarified, i.e., series, manufacturer, city, and country. 

6. Check the manuscript structure. I found dead space on several pages, such as Page 4.

7. Recheck the format. Are you sure there is no space between the end of a paragraph and the title of the new sub-section? For example, see lines 342-343.

8. Check the writing of chemical compounds. An example of an error is presented in 228.

9. Make sure all components of mathematical expression/equation are explained. The nomenclature may be considered to be composed.

10. See lines 309-310. Why letters (a) and (b) are so big in this manuscript? Check other figures.

11. Authors are demanded to restructure the writing. Ensure the explanation comes before the figures, tables, and equations.

12. Regarding results and discussions, explain all presented results. If there are Figures 8a and 8b, then the explanation must cover both Figures 8a and 8b. 

13. Give recommendations at the end of the Conclusion as future works based on your findings in this work.

14. Flowchart is a must in the Methodology. It must be clarified starting from the specimen preparation to the testing and result quantification.

15. Reference format must be revised and follow the journal guidelines.

Recheck the language and manuscript structures.

Make sure they match.

Author Response

Please see the attachment.

Author Response File: Author Response.doc

Reviewer 3 Report

In this work the effect of Nb content on Ti6Al4V coating prepared by using a laser cladding technology was studied in terms of phase transformations, mechanical properties, corrosion resistance, and biocompatibility in comparison with uncoated material.

 The aim is to obtain a coated material with excellent mechanical properties and biocompatibility, suitable for the application of orthopedic biomaterials.

This manuscript is easy to follow with few mistakes and uncertainties.   

The troubled sentences and plots highlighted in yellow with remarks are indicated in the attached pdf manuscript file containing pop-up messages. Please answer one by one of those remarks.

In my opinion in the overall perspective this manuscript has merit to be published provided a previous  revision is completed.

Comments for author File: Comments.pdf

In general the manuscript is easy to read and follow. There are a few sentences that must be rewieved. They are marked in the attached manuscript for revision.  I recommend the authors a carefull english review of the overall manuscript.

Author Response

Please see the attachment.

Author Response File: Author Response.doc

Reviewer 4 Report

Overall a well prepared manuscript that is of high relevance and importance to the academic field, despite this, there remains several improvements that can be made to enhance the overall comprehensiveness and applicability of the research work.

The paper provides a clear and concise summary of the study on the TixNb (x = 32.5-62.5 wt. %) alloy coating prepared by laser cladding, and the results of the mechanical properties, corrosion resistance, and biocompatibility of the alloy.

Figure 6: Y-axis typo "Friction Coefficent)

Figure 7: Laser cladding can result in a rough surface finish, which can be problematic for some biomedical applications where a smooth surface is required. The wear scare 3D morphology is interesting, but it only looks a the width of the scar, nothing about the depth, or curvature to allow the reader to understand more about the volume of material removed. 

The fatigue resistance of TiNb alloy coatings may be lower than that of bulk Ti alloys, which can limit its use in applications where cyclic loading is expected. More information should be cited on the implications from a fatigue perspective of using this type of coating. Delamination might occur before bulk wear of the coating and this effect should be studied in more detail. 

Good

Author Response

Please see the attachment.

Author Response File: Author Response.doc

Round 2

Reviewer 2 Report

All comments and recommendations have been addressed in the revised manuscript and rebuttal.

Author Response

Thanks for your review and reply to our work.