The Influence of Bias Voltage and Gas Pressure on Edge Covering during the Arc-PVD Deposition of Hard Coatings

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The aim of this work is to present a coating process with an intrinsic sharpening effect and to show investigations on deposited edges. The work is purely experimental and the results are of particular industrial importance. The following minor revisions are recommended prior to publication.

 

1-The language of the paper should be revised. In general, it is clear what the text describes. However, some expressions are written in colloquial language. These should be reviewed and academic language should be preferred.

2-Some coating terms in Table 1 are written in different formats. For example, TiAlN and Ti-AlN. It is recommended to eliminate these differences. 

3- What is the "dimension" given in Table 2? Is it the sample size? 

4- In the material method section, line 71 "....formed in twofold..." twofold is not very appropriate. Use another expression.

5- It is recommended to give a SEM image for the initial radius given in Table 3.

6- It is recommended to provide a schematic drawing describing the coating process and a photograph of the system.

7- When the SEM images given in Table 6 and Figures 1 and 2 are evaluated together, it is not clear how the edge radii are measured. The viewing angle of the SEM images given in Table 6 is not suitable for measuring edge radii.

8-In Section 3.4, it is recommended that the equipment used in the stability test method and the way in which the specimen is mounted be shown in an additional figure. 

  Comments on the Quality of English Language

The language of the paper should be revised. In general, it is clear what the text describes. However, some expressions are written in colloquial language. These should be reviewed and academic language should be preferred.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript titled "edge-related growth effects of PVD hard coatings" appears to have a scope broader than its actual content. Upon closer examination, the manuscript seems to be focused on the application of bias voltage. Therefore, if the title remains as "edge-related growth effects of PVD hard coatings", a rewrite of the manuscript would be advisable to better align its content with the stated title.

Comments on the Quality of English Language

minor

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Manuscript “Edge-related Growth Effects of PVD Hard Coatings” by Zimmer et.al. discusses a technological approach to adjust the final radius of coated edges with various nitride thin films using cathodic arc evaporation method. The film growth was controlled by changing bias voltage, coating pressure and initial radii of the substrate edge. Current manuscript presents very basic results of initial findings, i.e. the coated edge sharpness or roundness, optical observation of film qualitative adhesion, and stability based on scratching and calotte grinding process. The work will be interesting for the cutting tool coating developers. There are some minor comments that I would like authors to address.

1.      In the result section, authors talk about the “edge sharpening” based on the radius change after the coating was deposited. This is unclear how “edge sharpening” might occur. Please provide corresponding extended discussion what causes the sharpening effect. Authors also claim that SEM images in Table 4 (please check the sequence of numbers in the main text, page 7 line 163) clearly indicates that effect. I want to contradict the statement, as to the reader the sharpening occurring after the coating when compared to uncoated substrate is not very clear. Some kind of indication of what one has to look into on SEM images would be welcome.

2.      Chapter 3.2: Authors talk about coating adhesion. How was it determined: optically or….?

3.      Scratching tests. In methodology, authors mention twice the load change, but not the actual scratching length. In the result section pages 15-17, some additional explanations are needed. When scratching test are done on coatings, critical loads are measured which indirectly indicates coating ability to perform at required forces, speeds, cycles. When showing SEM images, it would be nice to indicate those critical loads or any other annotations to point to the positions that authors are talking about.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Why did the authors chose a bias voltage exceeding 500 V, whereas the documented studies listed in Table 1 utilized a bias voltage that was less than 500 V? A concise representation of Table 1 is advisable.

Comments on the Quality of English Language

Minor revision preferred.

Author Response

Please see the attachement. 

Author Response File: Author Response.pdf