Improved Adhesion of TiAlSiN Nanocomposite Coatings on Cemented Carbide Substrate by Pre-Implantation
Round 1
Reviewer 1 Report
The manuscript entitled "Improved adhesion of TiAlSiN nanocomposite coatings on cemented carbide substrates by pre-implantation" deals with the interesting topic of developing new coatings of improved properties deposited on cemented carbide substrates by reactive direct current magnetron sputtering. This article examines the effects of pre-implantation of several different elements (N, C, O) on adhesion strength, hardness, micro-structure, element concentration and depth profile of coatings. Various techniques such as Rockwell indentation, scratch test, nano-indentation measurement, X-ray diffraction, energy dispersive spectroscopy, Auger electron spectroscopy were used.
The paper represents a valuable contribution to the development of innovative coatings in the field of surface engineering. With its theme and presentations, it is considert to be acceptable to publish in the "Coatings" journal especially its Special Issue "Advanced Thin Films Deposited by Magnetron Sputtering".
In order to improve the quality of work, the authors are sugested to do the following changes:
1. Authors should provide an explanation of the abbreviations mentioned in the text such as:
line number 41: abbreviation "nc";
line number 42: abbreviation "LC5";
line number 67: abbreviation "PBII".
2. In the chapter " 2. Experimental details "authors should indicate the chemical composition YT 15 cemented carbide substrate. It is also important to have an information about the surface roughness before coating.
3. Line number 83: The abbreviation “dc“ must be in capital letters (dc → DC).
4. Line number 107: It is necessary to leave space before starting a new sentence (... the thickness of the film [12] .The element content ...)
5. Line number 111: When quoting a pressure of 4.3x10-6 Pa for Auger electron spectroscopy, it should be emphasized that it is an ultra-high vacuum.
6. Line number 146: Table 3 needs to be restructured so that the value of element concentration does not fall in two rows.
7. Line number 151 and 152: The abbreviation FWHM is not well described. It should be stated: “full width at half maximum“.
8. Line number 152: When mentioning values of the peak and referring to XRD patterns on Figure 2, it is not clear exactly on which peak is this referred to: (111), (200) or (220)?
9. Line number 152: Authors should indicate the Debye-Scherrer formula for evaluating the grain size because the literature [19] quoted as a reference does not mention this equation anywhere.
10. Line number 171: The description of scratch test should involve maximum applied force or a graphic representation of the scratch test result in the form of an acoustic emission - force diagram.
11. Line number 190: Table 4 needs to be restructured so that the words "Sample" or "Rockwell" does not fall in two rows.
12. Line number 190: When the authors indicate the values of the elastic module in Table 4 it is not clear whether this is a real elastic modulus or reduced Youngs modulus resulting from nano-indenature measurements. For values of hardness and modulus of elasticity, it is necessary to indicate the scatter of results as it is five repeated measurements on each sample. Authors also need to explain why the H/E ratio is important, the values of which are also given in Table 4. What are the HF1, HF2, and HF3 tags that are referred to in the column labeled "Rockwell". The text of the article states that the coating adhesion is an estimated Rockwell (HRC) indentation test with a 1470N load, so it's a "C" scale, not "F" scale, as it could be concluded.
13. Line number 192: On the Figure 4 needs to better emphasize places that correspond to characteristic forces "LC1" and "LC2"
14. Line number 201: Authors should clarify which equation was used to calculate the grain size: Debye-Scherrer formula previously mentioned or Hall-Petch formula that stands here.
15. Line number 218: According to Figure 5a) it is not a depth of 135 nm but 140 nm.
16. Line numbers 225 and 226: According to Figures 5b) and 5c) it is not a depth of 135 nm but 144 nm and 140 nm respectively.
17. Line numbers from 226 to 228: When the authors consider the thickness of the deposited coating and the depth of implantation area, why did not substantiate them with SEM images of cross-section coatings with different pre-implantation atoms?
18. When citing literature, it is necessary to state the title of the paper.
Author Response
Dear editor and reviewer of Coatings,
Thanks very much for your kind suggestions and scholarly guidance concerning the errors and inadequacies in my paper. We have addressed all the problems you have posed according to your advice. Currently our manuscript is supposed to have been polished and the quality has been improved thanks to your enlightening remarks and comments. Besides, all the modifications and revisions we have made in the manuscript have been marked in Red. Really appreciate your careful reading and editing. And we are looking forward to your kind reply. Any suggestions and comments are warmly welcome!
We appreciate the comments from the referees and we are delighted that all the referees have praised our work. We also thank the reviewer for raising important technical questions and giving helpful suggestions for improvement.
We have addressed all comments in a point-by-point manner and our specific responses are attached. Generally, we believe the revised manuscript provides better technical details and discussions in investigating how pre-implantation of different ions affects the coating-substrate adhesion. We thus hope the revised manuscript now fulfills the requirements for publication in Coatings, and if further work is needed then please do not hesitate to contact us.
Sincerely Yours,
Lei Wang
(on behalf of all authors)
Author Response File: 
Author Response.docx
Reviewer 2 Report
In the present manuscript „Improved adhesion of TiAlSiN nanocomposite coatings on cemented carbide substrate by pre-implantation“ (coatings-457091) it is suggested that the adhesive strength of TiAlSiN coatings on cemented carbide substrates can be enhanced by pre-implantation of N, C and O species. This argument is based on qualitative Rockwell indentation tests as well as scratch tests.
The authors write in the abstract:
„The improved adhesion could be explained by the grain refinement and surface energy enhancement of substrate by pre-implantation.“
(lines 20-21)
and in the conclusions:
„As has been discovered, the improved adhesion on TiAlSiN films is primarily caused by grain refinement and surface energy enhancement thanks to pre-implantation.“
(lines 240-242)
These conclusions are not justified by the presented data as explained in the following.
With respect to the grain size the authors state that:
„The grain sizes of samples 1-4 are 15.6nm, 13.5nm, 15.2nm and 12.7nm respectively, suggesting that the role played by pre-treatment of PBII in crystal lattice size of the deposited coatings is quite insignificant.“
(lines 152-155)
This statement is in conflict with the conclusion that the improved adhesion is primarily caused by grain refinement.
Surface energies are only discussed shortly with respect to literature:
„According to Tsai’s survey [17], the intensity of (200) peak is positively related with surface energy; as a result sample 2 has the largest surface energy. In this study, the increase of surface energy could be ascribed to the increase of the lattice dislocations and distortions in the cemented carbide substrate caused by the implantation of energetic particles [18], which subsequently refined the surface, raised the hardness and provided more nucleation sites [5].“
(lines 140-145)
I am not convinced that a change in peak intensity can be understood solely as surface refinement.
The presented AES data shows the effect of pre-implantation on the chemical composition of the substrate surface. However, the manuscript is completely lacking of a microstructural investigation of the interface. The question which has to be answered is:
Which (morphological/chemical/...) effect does the pre-implantation have on the substrate surface and why is the formed interface stronger compared to a synthesis without pre-implantation.
This knowledge may be gained by (high resolution) microscopy investigations and the manuscript can not be accepted in the present form.
Author Response
Dear editor and reviewer of Coatings,
Thanks very much for your kind suggestions and scholarly guidance concerning the errors and inadequacies in my paper. We have addressed all the problems you have posed according to your advice. Currently our manuscript is supposed to have been polished and the quality has been improved thanks to your enlightening remarks and comments. Besides, all the modifications and revisions we have made in the manuscript have been marked in Red. Really appreciate your careful reading and editing. And we are looking forward to your kind reply. Any suggestions and comments are warmly welcome!
We appreciate the comments from the referees and we are delighted that all the referees have praised our work. We also thank the reviewer for raising important technical questions and giving helpful suggestions for improvement.
We have addressed all comments in a point-by-point manner and our specific responses are attached. Generally, we believe the revised manuscript provides better technical details and discussions in investigating how pre-implantation of different ions affects the coating-substrate adhesion. We thus hope the revised manuscript now fulfills the requirements for publication in Coatings, and if further work is needed then please do not hesitate to contact us.
Sincerely Yours,
Lei Wang
(on behalf of all authors)
Author Response File: Author Response.docx
Reviewer 3 Report
The article reports on the improvement of adhesion of TiAlSiN nanocomposite coatings on cemented carbide substrate by pre-implantation. Prior to a publication, the paper should be completed and modified according to the following comments.
Comments and recommendation
1. The English (grammar, spelling…) needs to be further improved throughout the manuscript. A few examples below:
Line 85. ”Sample 1 as the reference substrate was deposited by TiAlSiN coating” , must be “Sample 1 as the reference substrate was covered/coated by TiAlSiN coating “
Line 118. “The cause that leads to this phenomenon is that…” must be re-write!
“intensified hardness”?
2. Abstract. The first two sentences are built in an inappropriate way. Please, re-write.
3. Introduction.
· Please, provide a set of suitable references for the first statement in the first paragraph. Perhaps, it is worth mentioning here a new type of transition-metal nitride coatings based on high entropy alloys (10.1016/j.compositesb.2018.04.015 ) and novel nanocomposites based on TiAlSiYN (10.1016/j.surfcoat.2018.07.010).
· Line 31-34. Please, support the claims with references.
4. Experimental details
· 2.1. Pre-implantation and deposition. It is mandatory to mention the type of ions used during the cleaning by glow sputtering (Line 74-76)
· Line 84-87. The sentence is difficult to understand. Please divide into 2 or 3 sentences.
· Line 85. “Sample 1 as the reference substrate was deposited…”. Deposited? May be covered/coated? Please, clarify!
· “while Sample 2, 3 and 4 were ions pre-implanted with nitrogen…”. The statement is not clear. Please, re-write! The samples must be pre-implanted with N, C and O ions? Right?
· Line 88. The statement that “the plasma was generated by a high substrate bias applied to the samples” cannot be correct! The plasma is generated by glow discharge of the magnetron. Moreover, the substrate bias voltage is applied to the samples in order to extract the ions from the discharge and accelerate them toward the samples for implantation. Please, rewrite to be clear!
· Line 102-104. Please, explain how you detected hardness and elastic modulus with nanoindentation.
5. Results and Discussion
· Line 121-123. Please, provide references to support the statement!
· Line 123-125. First of all, the absence of diffraction peaks corresponding to Si containing phases is not only a result of the formation of amorphous SiN in the coating! It is well-known from the previous studies on TiSiN and TiAlSiN that Si can substitute Al/Ti at cation lattice sites of the B1-NaCl lattice when concentration of Si is less than 5-6 at% in a coating. Secondly, it is not correct to state that this is an experimental conclusion! You do not provide an experimental evidence of the amorphous phase formation. To support this claim you should provide HRTEM images and XPS measurements. Please, re-write to be clear! Provide corresponding references!
· Line 128-129. Please, clarify which energy particles?
· Line 132. It is not obligatory to point on the amount of C atoms in this sentence.
· Line 133. The transformation is observed on XRD pattern. Right? Please, re-write.
· Line 140-142. The statement is a manipulation! It is unacceptable to state that the sample 2 has the largest surface energy because “According to Tsai’s survey [17], the intensity 140 of (200) peak is positively related with surface energy”. Is non sense! Clarify!
· Moreover, the change of the preferential orientation can be explained in terms of surface reactivity change after the implantation of different ions. This also can influence the surface energy. Please, consider this for interpretation of the results!
· Line 151-152. It is not clear which peaks were used for the calculation, since there are three peaks and the preferential orientation changes with implantation?
· Fig.2. What is marked with black vertical solid lines?
· Line 155-159. The sentences are not clear. Please, reformulate! The last sentence is not supported by experimental evidence.
· Sub-header s 3.2 and 3.3 should be re-wrote; I would propose “Adhesion and mechanical properties of the coatings” and “Elemental composition of the coatings”, respectively.
· Fig.3. Scale bars should be added.
· Line 161-170. The described and observed difference in deformation behaviour is not a consequence of the difference in adhesion only! As it is shown by XRD measurements, the coatings have very different microstructures with different preferential orientation! This difference can play a significant role in deformation. Please, take this into account for the interpretation.
· Line 182-183. Please, explain how the pre-implantation influence fracture and plastic deformation?
· It is worth adding in this section a comparison of your results with those reported earlier by other authors on the improvement of adhesion of hard coatings by pre-implantation. It can be added to Table 4. or in a separate table. Compare and discuss in 1-2 paragraphs.
· Fig.4.The scale bars should be increased.
· Line 201-204. The statements are not justified!
· Line 209-210 and 211-212. Re-formulate to be clear!
· In the experimental details you write that “The deposition time was adjusted so as to have a coating thickness of around 2.0μm.” but in lines 226-227 you write that “the thickness of all the deposited coatings is about 100 nm”. Please, clarify!
· Line 235. This is not a thesis, isn’t it?
· Line 237-238. You write “the adhesive strength depends heavily on the types of elements”. About what elements are you writing here?
· Line 240-243. These statements have not been demonstrated in the manuscript by experimental outcomes! Clarify!
· The conclusions are not sound and justified.
General comment! The article contains very valuable experimental outputs on the improvement of adhesion of TiAlSiN nanocomposite coatings, but they should be analyzed more detailed and interpreted correctly. Therefore, the major revision is necessary.
Author Response
Dear editor and reviewer of Coatings,
Thanks very much for your kind suggestions and scholarly guidance concerning the errors and inadequacies in my paper. We have addressed all the problems you have posed according to your advice. Currently our manuscript is supposed to have been polished and the quality has been improved thanks to your enlightening remarks and comments. Besides, all the modifications and revisions we have made in the manuscript have been marked in Red. Really appreciate your careful reading and editing. And we are looking forward to your kind reply. Any suggestions and comments are warmly welcome!
We appreciate the comments from the referees and we are delighted that all the referees have praised our work. We also thank the reviewer for raising important technical questions and giving helpful suggestions for improvement.
We have addressed all comments in a point-by-point manner and our specific responses are attached. Generally, we believe the revised manuscript provides better technical details and discussions in investigating how pre-implantation of different ions affects the coating-substrate adhesion. We thus hope the revised manuscript now fulfills the requirements for publication in Coatings, and if further work is needed then please do not hesitate to contact us.
Sincerely Yours,
Lei Wang
(on behalf of all authors)
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
I still keep my position from the first review: in order to understand the implantation-induced enhancement of adhesion, microstructural investigations of the interface are required. The hypothesis/notions of grain refinement and altered surface energy alone do not enable scientific understanding of the presented data. Therefore, the manuscript can not be accepted.
Author Response
Dear reviewer of Coatings,
Thanks very much for your kind suggestions and scholarly guidance concerning the errors and inadequacies in my paper. We have addressed all the problems you have posed according to your advice. Currently our manuscript is supposed to have been polished and the quality has been improved thanks to your enlightening remarks and comments. Besides, all the modifications and revisions we have made in the manuscript have been marked in Red. Really appreciate your careful reading and editing. And we are looking forward to your kind reply. Any suggestions and comments are warmly welcome!
We appreciate the comments from the referees and we are delighted that all the referees have praised our work. We also thank the reviewer for raising important technical questions and giving helpful suggestions for improvement.
We have addressed all comments in a point-by-point manner and our specific responses are attached. Generally, we believe the revised manuscript provides better technical details and discussions in investigating how pre-implantation of different ions affects the coating-substrate adhesion. We thus hope the revised manuscript now fulfills the requirements for publication in Coatings, and if further work is needed then please do not hesitate to contact us.
Sincerely Yours,
Lei Wang
(on behalf of all authors)
Author Response File: Author Response.docx
Reviewer 3 Report
The authors have significantly improved their manuscript following my comments and recommendations. However, there are still some issues needed for a solution:
The authors state that all the modifications and revisions we have made in the manuscript have been marked in Red. However, only figure captions and references are marked in Red in the pdf file. It is difficult to track the changes. Please, modify the file.
English still need a revision.
Line 124-125. Hardness (H) and elastic modulus (E) of the composite coatings cannot be detected by nano-indentation tester! You can only measure them! Please, re-write to be clear.
Line 306-309. This interpretation does not explain the outcomes presented in the manuscript. The difference of fracture and plastic deformation between the studied coatings can be assigned to the difference in microstructure (preferential orientation, grain sizes), elemental composition and the modification of the substrate/coating interface after pre-implantation. Please, modify and re-write to be clear.
Line 332-334. The sentence has to be re-formulated. The hardness cannot be "strengthen" as you write. It can be improved or enhanced. Modify to be clear.
Line 339. "about 100nm thickness coatings" should be "about 100 nm thickness of coating"
Conclusions. The conclusions should be extensively re-write with emphasis on the improvement of the adhesion and the observed changes in microstructure. You write "and the degree of improvement for the adhesive strength depends heavily on the types of elements". Do you mean types of implanted ions here?
Line 385-387. It is not clear about what element changes you are writing here.
Line 387-388In the results, you wrote: "The grain sizes of samples 1-4 are 15.6nm, 13.5nm, 15.2nm and 12.7nm respectively, suggesting that the role played by pre-treatment of PBII in crystal lattice size of the deposited coatings is quite insignificant". So how such a small change can lead to changes in hardness and elastic modulus? Please, clarify!
Author Response
Dear editor and reviewer of Coatings:
Thank you for your letter with referee comments about our manuscript “Improved adhesion of TiAlSiN nanocomposite coatings on cemented carbide substrate by pre-implantation” by L. Wang et al. We have addressed all comments and suggestions raised by you and referees and revised the manuscript accordingly. Please find attached the revised version of our manuscript, which we are resubmitting for consideration for publication in Coatings. All modifications in the manuscript are marked in RED.
We appreciate the comments from reviewer. We also thank the reviewer for raising important technical questions and making helpful suggestions for improvement.
We have addressed all comments in a point-by-point manner and our specific responses are attached. Broadly, we believe the revised manuscript provides better technical details and discussions in investigating how pre-implantation of different ions affects the coating-substrate adhesion. We thus hope the revised manuscript now fulfills the requirements for publication in Coatings, and if further work is needed from us, then please do not hesitate to contact us.
Sincerely Yours,
Lei Wang
Guodong Li
Quansheng Ma
Author Response File: Author Response.docx
