Tribological and Mechanical Properties of Multicomponent CrVTiNbZr(N) Coatings

Round 1

Reviewer 1 Report

Dear Sir or Madam:

The paper entitled, "Tribological and Mechanical Properties of Multicomponent CrVTiNbZr(N) Coatings" reports on the different mechanical properties of 5(6) component high-entropy alloys that are formed by PVD in a chamber with varying nitrogen flow-rates.  While the overall paper is well-done, I did have a couple of technical concerns and noted several grammatical, formatting, typo-type errors that should be addressed prior to publication.

Technical Concerns

1. Pg.2, line 19 - what high-speed steel alloy was used as a substrate?
2. Figure 1 - Please provide a schematic illustration of - or indicate on one of the micrographs - the columnar nature of the coatings because I could not discern it.
   1. Would it be possible to include EDS images of the cross-sections to determine if elemental segregation was occurring during growth?
3. Pg. 5, line 186 - "The nitrogen atoms formed the metallic chemical bonds and occupied octahedral interstitial sites, typical for NaCl-type lattice."  Please clarify the type of bonding with the Nitrogen as I would have assumed an ionic or covalent bond?
4. Pg. 7, lines 208-211 - I don't think the text matches with the layer compositions given in Figure 3b.  For example, dark layer composition in the figure is high in Zr while the text states that it is composed of TiNbN.
5. Also, please explain the source of the layer periodicity shown in Figure 3b.  
6. Pg. 10, lines 255-257: "Multilayer architecture of HEAN-N165 allows to achieve higher resist the plastic deformation comparing with HEA coatings due to the impeding dislocation motion across the interfaces."  This sentence is unclear.
7. Pg. 11, lines 288-291.  "Although the HEAN-N50 had higher hardness that that of WC-Co ball, the adhesion strength was not so good enough (class 2, small coating delamination was observed in the Rockwell indentation test), the abrasive wear resulted from the abrasion between wear particles of coatings and the coatings themselves."  This sentence is a run-on sentence and is also unclear.  Did the loss of adhesion between the layers in the coating lead to the formation of wear debris - thereby causing 3-body wear?  If so, which adhesion between the coating layers failed?

Other Concerns

The following errors made the paper more difficult to read and follow the technical thread.

1. There were numerous run-on sentences, for example:
   1. Pg. 2, lines 47-50
   2. Pg. 2, lines 64-67
   3. Pg. 7, lines 211-214
2. There were several run-on paragraphs, for example:
   1. Pg. 5, lines 172-200
   2. Pg. 5, lines 172-200
   3. Pg.11, lines 282-307
3. There were a number of misspellings, subject-verb agreement problems,  and typos.  For example,
   1. "harness"
   2. "many attentions"
   3. "quarternary"
   4. "is" instead of "are"
   5. no subscript on "N2"
   6. no superscript on exponents like "10-3"
   7. What are the units of "sccm"?
   8. Pg. 4, lines 151-153 and lines 156-157 seem to be duplicates.
   9. H3/E*2 is sometimes written with superscripts and sometimes not.

Author Response

Please see the attached file, which provide a point-by-point response to the reviewer's comments.

Author Response File: Author Response.docx

Reviewer 2 Report

The aim of the paper „Tribological and Mechanical Properties of Multicomponent CrVTiNbZr(N) Coatings“, is interesting and actual. Research into the possible improvement of the mechanical and tribological properties of functional surfaces by deposition of thin layers is still current. This can extend the life of the machines. Results published in this article have a sufficient impact and add to the knowledge base. The aim of the paper is in good agreement with expectations and focus of the journal. The paper is written in good English. The references are appropriate and up to date. In conclusion, I recommend this paper for publication with minor revision:

Line 13: instead of “many attentions“, use „much attention“

Line 15 and 16: instead of „are system that each comprised“, use „are system that are each comprised“

Line 17: instead of „much  better strength“, use „much higher strength“

Line 53: instead of „received many attentions“, use „received much attention“

Line 58: in „A.D. Pogrebnjak at al. [12]“, instead of „at al.“, use „et al.“                         

Line 62: in „had harness higher than“, instead of „harness“, use „hardness“

            In „than 24 GPa depended on“, instead of „depended on“, use „depending on“

Line 66: in „element materials, and the atomic percentage of“, instead of „and“, use „where“

Line 89-90: instead of „CrVTiNbZr(N) nitride coatings“, use „CrVTiNbZr(N) coatings“

Line 151: in „which in the range of“, instead of „which in“, use „within“

Line 159: in „increased higher than 50 at.%“, instead of „higher than“, use „above“

Line 163 and 164: instead of „were expected to interstitially incorporate“, use “were expected to be interstitially incorporated“

Line 211: in „Coatings with such a multilayered“, omit „a“

Line 213: in „demonstrated the ability in“, use „have demonstrated the ability in“

Line 242: Missing „i“ in „Posson’s“ (correct: „Poisson’s“)

            In „an indicator of the resistance to“, omit „the“

Line 289: in „was not so good enough“, omit „so“

Line 315 and 316: instead of „on coating microstructure as well as“, write „in coatings‘ microstructure, as well as“

Line 328: in „is observed for“, instead of „is“, use „are“

Line 330: instead of „grown“, use „growth“

Author Response

Please see the attached file, which provide a point-by-point response to the reviewer's comments.

Author Response File: Author Response.docx

Reviewer 3 Report

Article : Tribological and Mechanical Properties of Multicomponent CrVTiNbZr(N) Coatings present some interesting experimental results obtained with advanced techniques and high quality interpretations. 

I have few recomandations for the authors: 

Explain what is H3/E*2

• L103: 100A, and for other in text as well , 
• L170 : Is table 1 , Table or part of the figure 1 ? how many determinations were done ? 1,2 or more areas? , do you have a SD for each element determination ?
• Figures 1,4 and 7 must be re-arranged esspecially figure 7 which is to big (2.5 pages) or restructured 
• L136-137: you don t have to explain , again, what FEI-FESEM is or BEI-FESEM
• more comments are helpfull for figure 7   

 

Author Response

Please see the attached file, which provide a point-by-point response to the reviewer's comments.

Author Response File: Author Response.docx

Reviewer 4 Report

The paper is well written and contains a lot of informations. . The test methods and the procedures is well selected to answer the main research question. The conclusions are relevant . Can be accepted in the present form, however some improvement in text will be appreciated.

The line 62  please change harness for hardness

Author Response

Please see the attached file, which provide a point-by-point response to the reviewer's comments.

Author Response File: Author Response.docx

Reviewer 5 Report

Manuscript titled „Tribological and Mechanical Properties of Multicomponent CrVTiNbZr(N) Coatings” is a good scientific material.  The presented results are particularly significant from the point of view of the basic (cognitive) research of multilayers/multicomponent in terms of structure, morphology, as well as mechanical and tribological properties. Both the subject matter and the methodology of conducting experiments are described quite well - the research is conducted in a logical and consistent manner.

All comments are just improvement, not criticism. The entire manuscript has a very good scientific level.

The abstract contains all the most important information - purpose, scope and findings.

Introduction - section has an almost adequate informational level. The Authors properly described the importance of multilayers in terms of the layers wear improvement. The introduction does not mention the effect of the substrate on the abrasive wear and does not consider the method of joining the substrate with the layer (or interlayer). According to my knowledge, both the type of substrate and the type of connection (adhesive, mechanical, etc.) are important in mechanical and tribological tests – it is suggested to develop the literature review.

Materials and Methods/ Results and Discussion - the section is correctly described, but there is no information description of ISO 26443 standard procedure.

Questions/remarks:

- line 140 - scientific articles should be written in an impersonal form  - We can observe… It can be observed…;

- line 147 - check table numbering;

- line 149 – „at. %” is the same as „atomic percentage” – there is no need to repeat;

- line 156 – „41. 27 at.%” - formatting problem and unnecessary space;

-line 170 - check table numbering, and there is no table description, the table should be reformatted, the font size should be the same as in the text;

- line 217 (Figure 3) - there is some problem with font formatting in tables - tables have not been marked as tables only as part of the figure 3b - in my opinion they should be combined into one table and properly described (as a Table);

- line 223 - it is possible to determine the adhesive strength of coatings with the Rockwell C method? If you „determine” the adhesive strength then the value is needed, if classifying is rather „estimation”?. I do not know the content of the ISO 26443 standard, the procedure should be generally described;

- Figure 4 - the font size should be the same as in the text;

- Figure 5 and 6 - why are the values connected by a straight line - I can't see the correlation between the variables on the X axis. Hardness and friction coefficient should be marked with points, taking into account the measurement error;

- Figure 7 - it is difficult to compare the results in Figure 7 - maybe it would be better to combine them into Figure, where: a) HEA - for three samples, (b) HEAN-N50 - for three samples (c) HEAN-N165 - for three samples;

-- numerous editing errors - no space or double space - correction required;

-- most figures and tables need to be formatted - the font should be the same size as in the text.

 Conclusions drawn almost correctly - the first conclusion is written incorrectly (in this form it is not a conclusion) - it needs to be changed.

References selected correctly.

Author Response

Please see the attached file, which provide a point-by-point response to the reviewer's comments.

Author Response File: Author Response.docx