Laser Cladding of NiCrBSi/WC + W2C Composite Coatings
Round 1
Reviewer 1 Report
The manuscript investigates the effects of laser energy input on laser cladding of NiCrBSi/WC+W2C composite coatings and their wear resistance. The manuscript can be of interest to scientific and engineering community. However, I cannot recommend it in its present form for publication due to its lack of comprehensive analyses and discussions.
Some of the shortcomings follows;
- There are instances of typos. For example, line 16, 406, 407.
- A review of other works on the effects of laser energy input on laser cladding of the matrix alloy or similar alloys is lacking.
- Line 83: “The chemical composition of the matrix powder was selected so as to ensure good technological properties … with the carbides.”. Please add references for the statements.
- Line 87-90: please name the producers of the metal and the reinforcement powders.
- Line 137: Why Fig 12 has been cited before Figs. 3-11?
- Table 3: Is 5.1% dilution for LC1 correct?
- Please declare if the reproducibility of the experiments has been checked. How many times each experiment was repeated?
- Fig. 5: I believe that the error bars shown in the figure is not correct. How can all the error bars on any given curve be identical?
- Fig. 13: Why the results of LC1 have not been reported?
- For a full tribological investigation, weight loss-distance, coefficient of friction-distance of all samples, and micrographs of all wear tracks and debris need to be reported.
Author Response
Dear Reviewer,
Thank you for your comments and suggestions.
Referring to your comments, I provide detailed answers below. All changes in the main text are highlighted in blue.
- There are instances of typos. For example, line 16, 406, 407.
Answer: Typos are corrected.
- A review of other works on the effects of laser energy input on laser cladding of the matrix alloy or similar alloys is lacking.
Answer: The introduction is reorganized and extended. Additional literature items are discussed.
However, I pointed in the introduction that there is little literature on the same range of studies, related directly with laser cladding of specific NiCrBSi/WC+W2C composite coatings.
- Line 83: “The chemical composition of the matrix powder was selected so as to ensure good technological properties … with the carbides.”. Please add references for the statements.
Answer: References added.
- Line 87-90: please name the producers of the metal and the reinforcement powders.
Answer: The information provided. The supplier of the experimental powders was Durum from Germany.
- Line 137: Why Fig 12 has been cited before Figs. 3-11?
Answer: Reference to Figure 12 removed.
- Table 3: Is 5.1% dilution for LC1 correct?
Answer: Yes, this is the correct value.
- Please declare if the reproducibility of the experiments has been checked. How many times each experiment was repeated?
Answer: The experiments are fully reproducible, both for the experimental powder used in this study, as well as for other powders. Cladding tests are performed using an automatic and programmable stand, ensuring repeatability of settings and process parameters. Each single clad is produced at least three times for different tests and investigations. The values presented in Figures are mean values taken from a few calculation in different planes, as pointed in the main text of the manuscript.
- Fig. 5: I believe that the error bars shown in the figure is not correct. How can all the error bars on any given curve be identical?
Answer: This is due to the relatively small deviation values, but the error bars are not uniform. This is most clearly seen in Fig. 5b, which shows the effect of laser power on dilution. E.g. the error bar at the 1500W is significantly higher if compared to the first one at 500W. The same can be noticed on Fig. 5a for width curve. In other cases, the differences in the values in the graphs are relatively small, which causes the error bars to be narrow as well.
- Fig. 13: Why the results of LC1 have not been reported?
The LC1 clads were not omitted in the study. Most of the results include all clads. However, due to very narrow bead produced at the parameters LC1, the parameters were omitted during multi-pass coating of discs for ball on disc test.
- For a full tribological investigation, weight loss-distance, coefficient of friction-distance of all samples, and micrographs of all wear tracks and debris need to be reported.
Answer: Correct. However, the main purpose of the research is not a comprehensive analysis of wear mechanisms of the coatings. This scope of research is planned to be developed in subsequent articles.
I hope that the current version of the manuscript will meet the expectations of the reviewers.
Yours sincerely
Prof. Aleksander Lisiecki
Reviewer 2 Report
1) Figure 2 title is confusing need to be changed
2) in Figure 3 the phase of tungsten and carbon may be included
3) The details of wear test need to be given in a table.
4) the influence of applied loads during wear test and speed need to be highlighted
5) In Figure 13, 13a and 13b are seen to be contradicting each other. the specimen with low wear loss has a higher coefficient of friction. this needs explaantion
Author Response
Dear Reviewer,
Thank you for your comments and suggestions.
Referring to your comments, I provide detailed answers below. All changes in the main text are highlighted in blue.
1) Figure 2 title is confusing need to be changed
Answer: The description has been modified and shortened.
2) in Figure 3 the phase of tungsten and carbon may be included
Answer: Figure 3 presents the EDS spectra of elements. The tungsten is signed as "W" in Fig. 3c. Carbon, on the other hand, is generally not determined by eds analysis due to its low atomic number of 6. The results for carbon are unreliable.
3) The details of wear test need to be given in a table.
Answer: The following information is provided in the section Materials and Methods: The tribological tests of coatings were conducted by a ball-on-disc tribometer T-01M under room temperature of 22°C, and dry sliding conditions according to the ASTM G99 standard. The relative humidity was about 40%±5%. The discs were 45,0 mm in diameter, while the balls 10.0 mm in dimeter made of bearing steel (EN 100Cr6, AISI 5210) were used as the counterface material. The normal load was set as 20 N. The number of revolutions was 1500, while radius of the track was 15 mm. Therefore, the sliding distance was 141.3 m, while the sliding speed was 0.157 m/s.
4) the influence of applied loads during wear test and speed need to be highlighted
Answer: It is additionally highlighted in the section “Results and discussion / Tribological tests”.
5) In Figure 13, 13a and 13b are seen to be contradicting each other. the specimen with low wear loss has a higher coefficient of friction. this needs explaantion
Answer: It is additionally explained in the text. This phenomenon can be attributed to the share of carbides (eutectic WC+W2C) in the coatings, whose coefficient of friction is higher than that of the NiCrBSi metal matrix. Therefore, the higher the share of massive carbides in the coatings, the higher the coefficient of friction, Fig. 13b. In turn, the wear resistance of tungsten carbides is significantly higher than that of the NiCrBSi metallic matrix. Therefore, a higher proportion of carbides in the coating provides a higher wear resistance of such a composite coating.
I hope that the current version of the manuscript will meet the expectations of the reviewers.
Yours sincerely
Prof. Aleksander Lisiecki
Reviewer 3 Report
The article under review is devoted to a very topical scientific area of research, namely, the production of functional coatings with high properties on the surface of ordinary steel grades. The article may be useful to other researchers. The article may be published in a highly rated scientific journal, but I have a few comments
1. The introduction reflects the relevance of the work, the prerequisites for its implementation, but now the authors cite a very small number of studies previously performed on this topic. Half of these citations are on themselves. It should be noted that this topic is very popular in other countries. Here are just a few of the works:
https://doi.org/10.4028/www.scientific.net/SSP.118.579;
https://doi.org/10.1016/j.wear.2011.01.049;
https://doi.org/10.1007/s11015-021-01104-1
The number of citations needs to be increased.
2. In section 2. Materials and Methods, I recommend adding a photo or sketch (drawing) of the installation for coating, surfacing. I recommend adding a photo or sketch (drawing) of the setup for tribological tests. This will improve the understanding of the essence of the research for the readers of the article, increase visibility.
3. In section 3. Results and discussion, lines 178-200 repeat the information presented earlier in 2. Materials and Methods. Figures 1-3 should be moved to section 2. Materials and Methods, since that is where they are indicated in the text.
4. Why did the authors add exactly 65% WC? It would be interesting to investigate how the WC content affects the hardness and wear resistance of the coating.
5. Conclusions need to be clarified. Which surfacing modes allow obtaining the best coating properties?
Author Response
Dear Reviewer,
Thank you for your comments and suggestions.
Referring to your comments, I provide detailed answers below. All changes in the main text are highlighted in blue.
- The introduction reflects the relevance of the work, the prerequisites for its implementation, but now the authors cite a very small number of studies previously performed on this topic. Half of these citations are on themselves. It should be noted that this topic is very popular in other countries. Here are just a few of the works:
https://doi.org/10.4028/www.scientific.net/SSP.118.579;
https://doi.org/10.1016/j.wear.2011.01.049;
https://doi.org/10.1007/s11015-021-01104-1
The number of citations needs to be increased.
Answer: The introduction is reorganized and extended. Additional literature items are discussed.
However, I pointed in the introduction that there is little literature on the same range of studies, related directly with laser cladding of specific NiCrBSi/WC+W2C composite coatings.
- In section 2. Materials and Methods, I recommend adding a photo or sketch (drawing) of the installation for coating, surfacing. I recommend adding a photo or sketch (drawing) of the setup for tribological tests. This will improve the understanding of the essence of the research for the readers of the article, increase visibility.
Answer: A photo of the experimental setup is added.
- In section 3. Results and discussion, lines 178-200 repeat the information presented earlier in 2. Materials and Methods. Figures 1-3 should be moved to section 2. Materials and Methods, since that is where they are indicated in the text.
Answer: The lines 178-200 repeat are not in section Results and discussion. This is the section “Materials and Methods”. The information is not repeated in “Results and discussion”. However, I found a mistake in the line 180 referred to the load. It was corrected.
- Why did the authors add exactly 65% WC? It would be interesting to investigate how the WC content affects the hardness and wear resistance of the coating.
Based on literature reports, it can be concluded that a higher carbide content improves wear resistance under certain operating conditions. In turn, the tungsten carbides content in such type of composite powders is ranged usually 50% or a maximum of 60%. Therefore, the intention was to prepare a powder with a higher content of carbides than those available on the market or used in research so far. Powder compositions were determined by measuring the weight of matrix and carbide components using a laboratory balance, and then the powder was mixed.
- Conclusions need to be clarified. Which surfacing modes allow obtaining the best coating properties?
Answer: Conclusions are summarized by: The highest wear resistance was shown by the coating produced at the lowest energy input, within the analysed range, and the lowest dilution, and thus the highest share of tungsten carbides.
I hope that the current version of the manuscript will meet the expectations of the reviewers.
Yours sincerely
Prof. Aleksander Lisiecki
Round 2
Reviewer 1 Report
The authors have modified the manuscript according to the reviewer’s comments. I believe that the manuscript can be accepted with some suggested minor modifications.
- Following the 2nd comment by reviewer 1 and the 1st comment by reviewer 3, the authors have added a few new relevant work. But none of them discusses the effects of laser energy input on laser cladding of the matrix alloy or similar alloys.
- Comments about Fig. 13 and full tribological investigation by reviewer 1: Please mention the answers provided in the manuscript too.
Author Response
Dear Reviewer,
Thank you for your positive feedback.
Referring to your comments, the detailed answers are below. All current changes in the main text are highlighted in green.
- Following the 2nd comment by reviewer 1 and the 1st comment by reviewer 3, the authors have added a few new relevant work. But none of them discusses the effects of laser energy input on laser cladding of the matrix alloy or similar alloys.
Answer: Additionally explained in the Introduction section (green text)..
- Comments about Fig. 13 and full tribological investigation by reviewer 1: Please mention the answers provided in the manuscript too.
Answer: The additional information is added in the main text (green text).
Yours sincerely
Prof. Aleksander Lisiecki
Reviewer 2 Report
the authors incorporated the changes suggested. the manuscript can be accepted
Author Response
Dear Reviewer,
Thank you for your positive feedback.
Yours sincerely
Prof. Aleksander Lisiecki
Reviewer 3 Report
The authors corrected the peer-reviewed paper. I recommend the article for publication in this version.
Author Response
Dear Reviewer,
Thank you for your positive feedback.
Yours sincerely
Prof. Aleksander Lisiecki
