HIPIMS/UBM PVD Coating Equipment Designed to Coat Universal Sized Broaches

Round 1

Reviewer 1 Report

Thank you for such an interesting paper.

Please revise English. For example in abstract "hight" 

Please include notation in brackets for all acronymus HSS (High-speed steel), WC (Tungsten carbide)

Please consider including HV value in brackets for achieved HU 28GPa. According to https://www.pfonline.com/articles/the-relationship-between-vickers-hardness-and-universal-hardness corresdonds to 63GPa if extrapolation data of tests HU from 2 to 7 is suitable. Please check this carefully as in table line 362 you include values of HV 2800. Do you mean projected area hardness HV/94.5? Better incluede HV value in abstract and avoid confusion.

Please define if chamber diameter 1.2 m is the inner diameter of octagon or diameter of turntable shown in figure 2. Please include some dimensions in figure 2. 

Please make sure you use decimal point "." and not "," in text (in figures is ok)

Please include a scale bar in figure 1 and text to each part to be able to understand the equipment.

Line 54 change "here described here"

Line 79 change "and the di-ameter is given by"

Line 81 change "cath-ode"

Please avoid the use of cm.

Turntable rotates at 2 rpm but what is rotation speed of each tool holder? https://meaagg.com/agif/01DI_07Gear_Planetario.gif 

Please define equipment used for EDX, SEM... 

Please include a picture 10b of real cutting setup. It is not clear if we are turning, milling, drilling... 

Please define how to calculate "factor 2 to 3" stated in line 411. Is it possible to include literature factor improvements for coated versus noncoated broaches? Could you provide number for example for Taylo's basic model to calculate Tool Life?

How do you calculate 150% life improvement in line 423?

Please include in conclusions some comments on cost and coating times making clear all comparisons between type1, 2 and 3.

I think it would be easier for the reader to have a table with all values from Hardness, manufacturing times and cutting life.

Author Response

Dear reviewer, thank you very much for your notes, comments and suggestions.
Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

This manuscript describes a large-scale PVD coating equipment, and three types of coatings have been prepared with HIPIM and UBM processes by using the equipment. The results of cutting tests show that Type 2 coating has an excellent performance. I personally believe that there is a value in your work, and publishing your data would be great, but it still needs a further improvement. The following are my comments and questions regarding the data presented in the manuscript.

1. Though TiAlN-based coating proved to be better wear resistance or other properties than TiN, the introduction section should add some brief introduction about TiAlN-based coating.

2. There is a spelling error for the word “dendritic” in lines 293, 297, 301 of page 9.

3. It is fairly clear form Figure 8 that Type 2 exhibits distinct layered structure. What is the thickness of each layer? It would be better if it is marked. Whether this periodic layered structure should be the reason for its excellent performance, some discussion can be made.

4. The XRD were employed to characterize the crystal structure of deposited coatings, and it shows in Fig. 9 that the peak intensity of substrate is much stronger than that of the coating. Please give some necessary specific parameters and configurations during this test. If the focusing configuration was used, the strong peak from substrate may be the interference for analysis of coatings. The grazing incidence X-ray diffraction (GIXRD) is often suitable configuration to study coating samples.

5. The marks a, b, c in Figure 7 is not clear enough. A more obvious contrast should be used.

6. The caption of the Table is missing in page 11.

7. It would be better to provide an SEM image of the indentation pattern for Rockwell results.

8. From the Table type 2 exhibits the highest hardness and other good properties, but it shows poor wear resistance (the highest wear rate), then does the high wear rate mean that the service life of the coatings is the shortest when the coating thickness is the same? This is really puzzling. In the cutting tests, only type 2 and TiN coatings were compared.

Author Response

Dear reviewer, thank you very much for your notes, comments and suggestions.
Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

1. Try to use English standards for units and expression: e.g., it should be “2.2 m” instead of “2,2 m”. Check your manuscript.
2. The claims in the introduction seem to be very limited and not very solid. For examples, “…To prolong the life-time of these expensive tools in industrial use it is state of the art to protect them with hard coatings…” Indeed, coatings are only part of the common methods.

Currently, people are also using (nano)composites and surface treatment to achieve the same goal. The authors should include these discussions, and I believe the following references could help:

(1) New study on tribological performance of AA7075-TiB2 nanocomposites.

(2) Wear and corrosion behavior of P20 steel surface modified by gas nitriding with laser surface engineering.

3. Page 2 line 51: Cr++ means Cr²⁺? Please use the internationally recognized notion. Check all in your manuscript.

4. The scale bar and word color should be more distinguishable in Figure 7.

5. The axis and their words/numbers should be enlarged in Figure 9. Also, all figures should be of the same size.

6. Give the XRD index (which database and which index you use?) in Figure 9.

7. For Figure 9 (c), why do you think it is “randomly oriented”? Based on the intensity, it’s still favroing (111) and (200) only. Did you calculate the intensity ratio among these peaks? Please quantify to support your claim.

8. Page 11 line 362: Give the table titles and names. The authors MUST learn the scientific standard writing requirements!!! Also, for this table, did you measure these values or you referred to some data/manual? Give the sources.

9. Also, for this table, how many tests did you do for each type of materials and each category of tests? Give the stdev and error to guarantee the reproducibility!

10. In the table, you give the thickness of the coating. But these values are not well corresponding to the results from Figure 7. Why? (Of course, better high-quality SEM images should be provided).

11. Page 13 section 11: As I mentioned, this is scientific writing!!! The authors MUST shorten your (personal) acknowledgement. Refer to other scientific papers to see how the acknowledgement is structured. This version is TOO LONG!

Author Response

Dear reviewer, thank you very much for your notes, comments and suggestions.
Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

No more comments. They have made substantial changes to meet my requirements.

Author Response

Thank you very much for your time and effort.