Effects of WC Particle Types on the Microstructures and Properties of WC-Reinforced Ni60 Composite Coatings Produced by Laser Cladding
Round 1
Reviewer 1 Report
Please fide the comments below.
Materials and Experimental Procedure
„...a stainless steel 304 with the dimension of 100 mm × 65 mm× 10 mm was used as the substrate, of which the surface was polished to remove the oxide layer...”
Comment: Please explain why did you apply polishing instead just grinding or cleaning with sandpaper. What is the benefit of polishing the surface before laser processing ?
“The stainless steel sample was preheated at 500 ° C before the test...”
Comment: What was the reason of preheating ? Why the temperature of 500 Celsius was set ?
“Composite powders were conveyed by coaxial powder feeding method...”
Comment: The commonly used term is “delivered” or “transported”
“...powder feeding rate of 7 r/min, ...”
Comment: What is this unit r/min ? The powder feeding rate is typically given in grams per minute. If you provide repetitions per minute it refers to the setting of the feeder. The real powder feeding rate will be dependent on the specific weight of the powder. Since you used just one set of parameters, please explain how the parameters were chosen, and whether the parameters set is optimal.
In the case of electrochemical working station you provide detailed information on the type, designation and manufacturer. Therefore, provide such detailed information for the others used apparatus (OM and SEM microspores and EDS spectrometer, tribotester).
Results
“...the bonding layers are relatively flat...”
Comments: What do you mean “bonding layers”?
“...and have little distribution on the surface of the cladding layer.”
Comments: What do you mean “on the cladding layer”?
The number in Fig. 2 are small and illegible.
Regarding the Fig. 5., you provide the weight loss. However, according to the standards, the volume loss should be calculated. The specific weight of Ni60 powder is different than for the composite powders.
Conclusion
2. “...pherical WC...”
Comment: Correct the mistake.
Author Response
Dear professor,
Thank you very much for your letter and the comments from the referees about our paper submitted to metals-500045.
We have learned much from the reviewers’ comments, which are fair, encouraging and constructive. After carefully studying the comments and your advice, we have made corresponding changes. Our response of the comments is enclosed at the attachment. Thank you.
Sincerely yours,
Pengxian Zhang
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Improving surface wear resistance of materials by coatings is the one main aims of today surface engineering.
The mass wear quantity in Fig. 5 gives rather limited information about the wear resistance, because it strongly depends on the load. That is why two specific coefficients should be additionally calculated, as it is shown in the following paper, which should be added to the references:
Main directions of recent works on Al-Zn-based alloys for foundry engineering, J. Mater. Eng. Perform. 28 (6) (2019) DOI: 10.1007/s11665-019-04048-5.
These are specific coefficients of mass Wm and volume Wv wear:
Wm = Mw/(FN *SD) [g/(Nm)]
Wv = Vw/(FN *SD) [mm3/(Nm)]
where: Mw – mass wear [g], Vw – volume wear [mm3]; FN – load [N] and SD – sliding distance [m].
These two values of the specific coefficients Wv and Wm related to the volume and mass wear can be added as a separate figure, e.g. Fig. 5(b) or as additional data in Fig. 5.
It should be noted that the mentioned coefficient will allow comparing the presented results with the another ones dealing with coatings wear resistance, published in literature. The obtained values of the mentioned coefficients should be also considered in conclusions. It will certainly improve quality of this paper and additionally will allow avoiding possible questions/discussions of this journal readers.
Author Response
Dear professor,
Thank you very much for your letter and the comments from the referees about our paper submitted to metals-500045.
We have learned much from the reviewers’ comments, which are fair, encouraging and constructive. After carefully studying the comments and your advice, we have made corresponding changes. We will add coefficients of mass Wm and volume Wv wear in this manuscript. Your suggestions will help improve the quality of this article. Thank you.
Sincerely yours,
Pengxian Zhang
Reviewer 3 Report
This manuscript reports the laser cladding of Ni60 using 3 types of WC particles: spherical, shaped and nanosized flocculent. Results indicate the more uniform coating of Ni60 by WC flocculent particles which increased its corrosion resistance. The hardness of the other 2 WC particles were considerably better, and flocculent WC exhibited lowest hardness and friction coefficients in this study, thus being more susceptible to wear and cracks. Results will allow for proper selection of WC particles for specific applications of Ni60. Data is well presented and support the conclusions; materials are properly referenced to text is very well written. I have only one question which authors may choose to address at their discretion: have authors looked into EDX mapping for Ni of worn samples (see Figure 6)? I wonder if that would aid the visualization of the wear on those surfaces.
Author Response
Dear professor,
Thank you very much for your letter and the comments from the referees about our paper submitted to metals-500045.
We have learned much from the reviewers’ comments, which are fair, encouraging and constructive. EDX mapping for Ni of worn samples (see Figure 6) can aid the visualization of the wear on those surfaces, but may influence the quality of the visualization. Your suggestions will help improve the quality of this article. Thank you.
Sincerely yours,
Pengxian Zhang
