Effect of Heat Dissipation Rate on Microstructure and Mechanical Properties of Al0.5FeCoCrNi High-Entropy Alloy Wall Fabricated by Laser Melting Deposition
Round 1
Reviewer 1 Report
Dear authors,
thank you for your interesting contribution on High Entropy Alloys.
I have checked the manuscript and I have the following comments/questions:
1. Fig 1b: Please calculate the density distribution /(1/µm), not the probability distribution (%) to make it comparable. This is necessary since your intervals are not evenly spaced
2. lines 95-98: please give the powder low rate in mass/time, not in volume/time. volume flow will depend a lot on powder flowability and can not be transferred to other setups. How and where did you measure the oxygen content?
3. Fig. 3b: The positions of the thermocouple can not be compared, since they are in a totally different position in the heat flow field (horizontal heat flow at the top, vertical at the bottom). Also, the distance to the sample appears to be totally different
4. Fig. 6: The is a typo in „substrate“
The fact that the peak values of the heating rate changes over time means that there will a strong changes in the thermal history of the sample over thickness. While Fig. 7 shows images per setting, I am missing a top/bottom comparison of each sample. Same for following analysis. You can skip this if you can prove the samples are homogeneous over height (which I would doubt from thermal history plots)
5. Lines 390ff: wrong text formatting (font size)
6. Fig 15: Please put data in a 2D graph. This is tough to compare quantitatively
7. Fig. 16: Why did you choose number of grains and not grain size and/or a shape factor? number is not independent of sample size
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The paper shows very interesting results in terms of HEA materials properties, I will recommend the manuscript for publication after the following revisions:
1. Line 23 “Furthermore, the slow heat dissipation rate changed the grain number and BCC phase content, which gradually decreased the strength and hardness of the samples and improved the ductility.” Should be rephrased as” Furthermore, the slow heat dissipation rate changes the grain number and BCC phase content, which gradually decreases the strength and hardness, while the ductility of the samples improves.”
2. The references from introduction should be extended: DOI10.1007/s00170-022-09646-7; DOI10.1016/j.rinp.2021.103880.
3. Line 47 – how this research is valuable? How does the dual – phase structure change the properties?
4. Line 48 – there are too many repetitions “welding…weld..welding” rephrase the sentence
5. Line 53 – the microstructure influences the hardness properties, it is not a property!!!
6. Line 57 – you talk about mechanical properties, but I only found information about hardness, are there any other properties resulting?
7. Line 66 – the paper provides an experimental study, not a theoretical one.
8. Line 79 – how were the particles mixed to form HEA? In situ by using 5 hoopers or premixed in a ball mill? If you used a ball mill, how many rpm and how much time?
9. All the legends figures should contain the type of the presented analysis: OM, SEM, XRD, EBDS….
10. Every mentioned equipment should be followed by the producer and its country.
11. Please rephrase the paragraph from lines 86-87
12. How did you decide on the scanning strategy? But laser processing parameters????
13. What is the wavelength of the laser
14. What is the height of the wall obtained by 10 layers? How many layers did you perform to obtain 20 mm, 40 mm and 60 mm height? Does the height have a linear growth?
15. Line 114 – “the thermocouples were placed 12 mm below the top of the beam” …. Which beam?? Laser beam? And why 12 mm below?
16. Line 123 – the European name of the cutting machine is “ electric discharge” not spark … have you used wire or massive electrode? Which type of machine?
17. Line 123 – In order to reveal the microstructure, the polished metallographic samples…….. please insert this in front of the sentence
18. Line 143 – how were the tensile samples cut? Have you used a standard dimension of these tensile shapes? If not, why??
19. Line 160 – please rephrase that sentence, it is confusing
20. Line 177 – figure 6 is double time mentioned
21. Line 186 – too many repetitions, you should drastically improve the English of the entire paper
22. Line 210- 215 – figure 7 a-d are not mentioned in the text
23. Line 273 – refer to equation 1 in the text; same for eq 2, 3 and 4. Are the equations developed by the authors? If not, please, insert references
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Dear Authors,
thank you for your responses.
Response 1:
There was a misunderstanding. I was asking for the density distribution, which means you have to divide the probability by the interval width. The probability distribution cannot be compared to any other measurement, especially since your interval width changes. Please change this graph.
Response 2:
(1) Actually, I was asking for the flow rate in mass/time (such as g/min g/s) for the powder mass flow. The Feeding speed in RPM is not useful at all since this is dependent on the used machine. Please give an actual mass flow in g/min or g/s. I assume you have measured the mass flow rate, if not, this can be easily done with a balance.
(2) I am sure you have properly investigated process parameters. Please give actual numbers of these parameters in your study. Do not refer to other studies. The readership wants to know under what conditions these results were obtained.
Scientific publication is about enabling others to reproduce experiments by giving them all the required information needed. Please read your manuscript carefully and check if you have all the required information only from the manuscript to be able to do your experiments again.
Response 3:
(1) I agree that conduction is the most dominant mechanism, and I am talking about conduction, not convection or radiation. This is where my question is coming from: I do not see how to correlate the volumes, through which the heat is conducted and also their total heat capacity with each other. You are measuring the temperature field at totally different characteristic positions.
(2) This does not answer my question. But OK…
Response 4:
The measured thermal history shows that your assumption and also the provided explanation is wrong.
Response 7:
Yes, I understood that. But the actual grain number also does not say anything about the morphology. From the grain number, you could calculate the average grain area and a shape factor describes the morphology. This can be done with a free software like ImageJ quite fast. The number of grains is not a value that can be compared to any other study.
I have to conclude that you did not answer my questions appropriately, and none of your answers have found their way in the manuscript.
Since the majority of the manuscript changes are formal changes, I have to summarize that this manuscript is still not in the condition for publication. It still lacks scientific soundness.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 3
Reviewer 1 Report
Dear Authors,
thank for answering my questions!
