Analysis and Control of Cracks in Ni60 Coating of 7050 Aluminum Alloy by Electron Beam Cladding

Round 1

Reviewer 1 Report

Comments for author File: Comments.pdf

Author Response

Thanks for your advise，I have made changes in the latest version of the manuscript.

Author Response File: Author Response.pdf

Reviewer 2 Report

first of all, the title of the manuscirpt is not explicite. According to the present title, one can not know any more the cracking defect is observed in 7050 base alloy or in cladding coating. So, it is absolutely to change the title to lead a better understanding.

secondly, the crack rate should be associated with a right unity in all manuscript to avoid ther confusion.

Thirdly, the description of the 2 orders (premary and second) of the  process parameters should be managed with 3 different parameters (electron beam current, scanning speed, focusing current). It is necessary to indicate the 3 different orders instead of only 2 ordrers in whole manuscirpt.

Fourthly, in part 2 (ansys T field simulation), it is important to precise the used input parameters for used materials (substract and powder ?); the origin of these parameters (from bibliography or your own measurement ?); the used process parameters with justification. It is also important to indicate the limit conditions for simulation and discuss the precision/error/validity of the simulation reuslts. In the caption of the figure 1, it is necessary precise the different simulation conditions for each curves with a minimum description to lead a quick understanding without checking necessary information beteween lines in manuscipt.

furthermore, some details should be added to improve the results presentation:

• it is very important to precise the sample geoemtry in part 3 (Materials and Methods): substract dimension, coating thickness, microscope observation zones and observation view (only on surface ? in cross-section ? at interface ?)
• in caption of figure 2, it is absolutely necessary to precise the observation zones (in coating ? in substract ? on the top surface ? in cross-section ? ) comparing to the sample geometry; in each photo of the figure 2, it is extremely important to add a scale;
• in table 3, it is necessary to precise the crack rate unity and the determination method; it is absolutely necessary to add an analysis precision/error with each value;
• in caption of table 4, it is necessary to precise the physical meaning of the K value with a minimum information about the results validity in considering the 4 digital numbers after the point; 
• in figure 3, it is necessary to associate an error bar with each presented value;
• there are TWO figure 3. In figure 3BIS, it is necessary to indicate explicitely the coating zone and the substract zone with arrows in each photo to leave right information;
• there are TWO table 3. 

 

Author Response

first of all, the title of the manuscirpt is not explicite. According to the present title, one can not know any more the cracking defect is observed in 7050 base alloy or in cladding coating. So, it is absolutely to change the title to lead a better understanding.

Thanks for your advise, I have changed the title to  Analysis and control of cracks in Ni60 coating of 7050 aluminum alloy by electron beam cladding

secondly, the crack rate should be associated with a right unity in all manuscript to avoid ther confusion.

Thanks for your advise, the crack rate is unified in the full text. The crack rate in Table 4 is the detection result of the crack after processing, while Table 5 is the K value of the crack rate in Table 4.

Thirdly, the description of the 2 orders (premary and second) of the  process parameters should be managed with 3 different parameters (electron beam current, scanning speed, focusing current). It is necessary to indicate the 3 different orders instead of only 2 ordrers in

Thank you for your suggestions, I have made changes in the latest version of the manuscript.

Fourthly, in part 2 (ansys T field simulation), it is important to precise the used input parameters for used materials (substract and powder ?); the origin of these parameters (from bibliography or your own measurement ?); the used process parameters with justification. It is also important to indicate the limit conditions for simulation and discuss the precision/error/validity of the simulation reuslts. In the caption of the figure 1, it is necessary precise the different simulation conditions for each curves with a minimum description to lead a quick understanding without checking necessary information beteween lines in manuscipt.

It has been modified, and all the material parameters used in ANSYS simulation are listed in Table 1. Because figure 1 b) And 1 c) In the simulation, the parameter value is slightly larger than the temperature range, and smaller than the temperature range. There is no value just on the lowest or highest temperature line. In order to more clearly represent the temperature range, four different values of the parameter are selected.

 

furthermore, some details should be added to improve the results presentation:

• it is very important to precise the sample geoemtry in part 3 (Materials and Methods): substract dimension, coating thickness, microscope observation zones and observation view (only on surface ? in cross-section ? at interface ?)

 

Thanks for your advise, substrate size 50mm×20mm×10mm, coating thickness 1mm, Figure 2 test area for surface, Figure 4 test area for cross section.

 

 

• in caption of figure 2, it is absolutely necessary to precise the observation zones (in coating ? in substract ? on the top surface ? in cross-section ? ) comparing to the sample geometry; in each photo of the figure 2, it is extremely important to add a scale;

 

With regard to this problem, I have made changes in the latest version of the manuscript.

 

• in table 3, it is necessary to precise the crack rate unity and the determination method; it is absolutely necessary to add an analysis precision/error with each value;

 

With regard to this problem, I have made changes in the latest version of the manuscript.

 

 

• in caption of table 4, it is necessary to precise the physical meaning of the K value with a minimum information about the results validity in considering the 4 digital numbers after the point; 

 

Because both Level 1 and Level 2 in the Focus Current column of Table 5 have the same three decimal places, four decimal places are retained in order to determine which is better between Level 1 and Level 2.

 

• in figure 3, it is necessary to associate an error bar with each presented value;

 

With regard to this problem, The first and second paragraphs in 4.3 in the latest version of the manuscript are the explanation of the crack rate versus each parameter.

 

 

• there are TWO figure 3. In figure 3BIS, it is necessary to indicate explicitely the coating zone and the substract zone with arrows in each photo to leave right information;

 

Thanks for your advise, I have made changes in the latest version of the manuscript.

 

 

• there are TWO table 3. 

 

Thanks for your advise, I have made changes in the latest version of the manuscript. table 6 is on page 7

Author Response File: Author Response.pdf

Reviewer 3 Report

In their manuscript, Dr Liu et al. described the study of the e-beam process for cladding Ni60 coating. They used ANSYS simulation and orthogonal experimental method to extract the good parameters for the cladding. 

The overall impression of this manuscript is preliminary and fragment, lacking of sufficient experimental results, and thus cannot merit the standard of publication in Coatings in that state.

A lot of grammatical mistakes or errors are present. The manuscript needs be corrected and english should be corrected by a native language speaker.

Due to a lack of information about experimental conditions, some parts of the discussion are not clear and some results are not well described and supported. For example the paragraph on page 5 line 148: what is Ii, s, ...? there is no link with the previous paragraph or it is not clear.

The legend of each figure should be completed with all parameters and more described. 

There are only 10 references. I think the authors should introduce a little bit more the literature about this field. the introduction is too short. for example, authors mentioned that some toughness components are added but no reference or example. 

In the main text, the figure should be mentioned as "figure 1.c".

references and interval are both between brackets. the authors should correct. please verify unit for the scan speed mm/s in main text instead of m.s-1 in table 3&4.

for the crack rate what does it mean "0.01~0.017"? it is not clear.

Table 3 (page 5) seems not used in the main text. there are two tables "3" (on page 5 and 7).

From table 3 to 4 the focus current goes from ~700mA to 0.02 mA. is it correct? same comments for electron beam and scanning speed.

Author Response

In their manuscript, Dr Liu et al. described the study of the e-beam process for cladding Ni60 coating. They used ANSYS simulation and orthogonal experimental method to extract the good parameters for the cladding. 

The overall impression of this manuscript is preliminary and fragment, lacking of sufficient experimental results, and thus cannot merit the standard of publication in Coatings in that state.

Thanks for your advise, due to the lack of clarity in the previous text resulting in poor coherence of the article, I have revised it in the latest version of the manuscript.

A lot of grammatical mistakes or errors are present. The manuscript needs be corrected and english should be corrected by a native language speaker.

Thanks for your advise, I have revised it in the latest version of the manuscript.

Due to a lack of information about experimental conditions, some parts of the discussion are not clear and some results are not well described and supported. For example the paragraph on page 5 line 148: what is Ii, s, ...? there is no link with the previous paragraph or it is not clear.

With regard to this problem.   denotes the sum of the crack rates corresponding to level number i in any column; s is the number of occurrences of each factor level on any column.

The legend of each figure should be completed with all parameters and more described. 

With regard to this problem. The process reference of Figure 2 is shown in Table4, and the Crack Rate in Table 4 is the crack detection result of Figure 2.

There are only 10 references. I think the authors should introduce a little bit more the literature about this field. the introduction is too short. for example, authors mentioned that some toughness components are added but no reference or example. 

Thanks for your advise, I have revised it in the latest version of the manuscript.

In the main text, the figure should be mentioned as "figure 1.c".

Thanks for your advise, I have revised it in the latest version of the manuscript.

references and interval are both between brackets. the authors should correct. please verify unit for the scan speed mm/s in main text instead of m.s-1 in table 3&4.

Thanks for your advise, I have revised it in the latest version of the manuscript.

 

for the crack rate what does it mean "0.01~0.017"? it is not clear.

The crack rate refers to the ratio of the crack area to the detection area, which I explained in the fourth line of the penultimate paragraph in Figure 2. 0.01~0.017 refers to the crack rate between 0.01~0.017 for electron beam flow selection between 25 and 30.

 

Table 3 (page 5) seems not used in the main text. there are two tables "3" (on page 5 and 7).

Thanks for your advise,Table 3 is used at the end of section 3, and Table 6 is on page 7, which has been modified.

From table 3 to 4 the focus current goes from ~700mA to 0.02 mA. is it correct? same comments for electron beam and scanning speed.

Thanks for your advise, the crack rate is unified in the full text. The crack rate in Table 4 is the detection result of the crack after processing, while Table 5 is the K value of the crack rate in Table 4.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

1. The authors have not attempted to define the error on the crack rate in Figure 3 (according to authors crack rate is crack area/scanned area for this manuscript - I am not sure but that is what I am guessing).
2. Rate usually means something changing with time. The way "crack rate" has been defined it looks more like crack areal density. For the reviewer it causes a confusion.
3. The crack areal density depends on where you are looking as the authors themselves say the crack distribution is random. So there should be some sense as to why 45 mm of scanning length was chosen to take crack images.
4. Finally, with 4 parameters and 9 data points it is possible to fit any model. So not sure the general applicability.

Author Response

Dear Reviewer, I'm very sorry for not responding in time as I didn't see the last rework comments.

sorry! Thank you for your understanding!

Comments/Questions:

1. The title does not convey the information correctly. It is recommended that the authors revise the title in such a way to accurately reflect their paper.

 

Thanks for your advise, I have changed the title to Analysis and control of cracks in Ni60 coating of 7050 aluminum alloy by electron beam cladding

 

2. Abstract can be rewritten to present the information in a much more lucid way. There are numerical values mentioned in the abstract that looks like reference. Kindly write to avoid confusion.

 

Thank you for your suggestions, I have made changes in the latest version of the manuscript.

 

 

3. Please mention in Fig. 1 caption what (a) (b) (c) and (d) denote rather than just a title.

 

Thank you for your suggestions, I have made changes in the latest version of the manuscript.

 

4. Line 121 says, “distribution of cracks is shown in Fig. 2”. This is not right. The authors shown only pictures not a distribution of it.

 

Thank you for your suggestions, I have made changes in the latest version of the manuscript.

 

5. Line 123 says “…use area as statistic”. This is unclear and needs to be written clearly. Please note that this is not a grammatical or usage error. Please explain what is meant by that statement.

 

Thank you for your suggestions, I have made changes in the latest version of the manuscript.

 

 

6. Line 124 is inside a bracket, though it reads as an independent information6.

 

The information inside the brackets is independent information, an explanation of the previous information

 

7. Line 125 reads “…the nine inspection points are all taken at 45 mm of the scanning length”. How was this distance arrived at? How will the results change if you have look at a different position? 7.

 

Thank you for your suggestion! I have modified. This is a question that I did not understand enough. If a set of unreasonable process parameters are selected for cladding, for the entire cladding layer, the cracks as a whole are more; the selection of a set of preferred process parameters cladding, for the entire cladding layer, the crack as a whole is less; we will not detect the entire cladding layer at the time of detection, and will choose a region for detection. For the entire cladding process under a certain set of process parameters, at the beginning stage of cladding, there are fewer cracks, and at the end of cladding, there will be a collapse of the molten pool; so I chose a place where cracks are easy to produce.

 

8. Lines 135 to 136 describing the way crack rate average is calculated is confusing and needs to be rewritten.

 

Thank you for your suggestions, I have made changes in the latest version of the manuscript. The paper use crack areal density to provide data for subsequent analysis.

 

 

9. The very critical parameter: crack rate has not been defined. The authors do not explain how they measured the “rate”.

 

Thank you for your suggestion, this is my translation is not accurate enough, I have revised.

 

10. Some figures and some tables have the same number: Example Figure 3 and Table 3. 10. 一

 

Thank you for your suggestions, I have made changes in the latest version of the manuscript.

 

11. What is the error on crack rate in Figure 3?

 

Figure 3 shows the trend of the effect of each factor on the crack areal density in the horizontal interval，not the error on the crack areal density. From the F-test, the error is within ten percent.

 

12. In line 236 it says “ the three process parameters depend on and restrict each other”. The referee is confused – if they are dependent on each other how was orthogonality testing applied. Orthogonality testing assumes that process parameters are orthogonal to each other. The referee thinks the authors are talking about the cracks as process parameter changes and not about the process parameters themselves.

 

Thank you for your suggestions, I have made changes in the latest version of the manuscript.

 

13. line 246 instead of crack rate authors have written crack ratio. 13.

 

Thank you for your suggestions, I have made changes in the latest version of the manuscript.

 

 

14. Line 254, it says the regression fit is to data in Table 1, which the referee is assuming to be Table 3. There are 4 fitting parameters including the coefficient with 9 data points which makes the model highly specific to the model and cannot be generalized. So, the aim of the manuscript is defeated. The authors should have fit with a much larger data set.

 

From equation 2, we can see that k，α，b，γare coefficients， I ，V， I₂ are the parameters，Three factors and three levels can be fitted .The fitting accuracy will be lower for 9 groups of data, and higher accuracy will be achieved for more data.

 

 

 

 

1. The authors have not attempted to define the error on the crack rate in Figure 3 (according to authors crack rate is crack area/scanned area for this manuscript - I am not sure but that is what I am guessing).

 

Figure 3 shows the trend of the effect of each factor on the crack areal density in the horizontal interval，not the error on the crack areal density. From the F-test, the error is within ten percent.

 

1. Rate usually means something changing with time. The way "crack rate" has been defined it looks more like crack areal density. For the reviewer it causes a confusion.

 

Thanks for the suggestion, I've changed the crash rate to the crack areal density.

 

1. The crack areal density depends on where you are looking as the authors themselves say the crack distribution is random. So there should be some sense as to why 45 mm of scanning length was chosen to take crack images.

 

Thank you for your suggestion! I have modified. This is a question that I did not understand enough. If a set of unreasonable process parameters are selected for cladding, for the entire cladding layer, the cracks as a whole are more; the selection of a set of preferred process parameters cladding, for the entire cladding layer, the crack as a whole is less; we will not detect the entire cladding layer at the time of detection, and will choose a region for detection. For the entire cladding process under a certain set of process parameters, at the beginning stage of cladding, there are fewer cracks, and at the end of cladding, there will be a collapse of the molten pool; so I chose a place where cracks are easy to produce.

 

1. Finally, with 4 parameters and 9 data points it is possible to fit any model. So not sure the general applicability.

 

For this problem, The data and models are only suitable for 7050 aluminum electron beam cladding Ni60 powder coating, or the thermal properties of the matrix material are the same as those of 7050 aluminum alloy, and the thermal properties of the powder material are the same as those of Thermodynamics of Ni60 powder.

 

Author Response File: Author Response.docx

Reviewer 2 Report

in the revised version of the manuscript, author has made some corrections including most of remarks from reviewers.

one minor correction shoud be made to lead a better understanding about the results: in the caption of figure 2, it is important to precise the observation zone (in coating surface ? in coating cross-section ?) and what correspond to the 9 different photos ?

Author Response

in the revised version of the manuscript, author has made some corrections including most of remarks from reviewers.

 

one minor correction shoud be made to lead a better understanding about the results: in the caption of figure 2, it is important to precise the observation zone (in coating surface ? in coating cross-section ?) and what correspond to the 9 different photos ?

Thank you for your suggestion! I have modified this issue. Figure 2 is detected at the surface of the cladding layer.

Author Response File: Author Response.docx

Reviewer 3 Report

V2 part in doc file

Comments for author File: Comments.pdf

Author Response

The authors have modified their manuscript following some of my remarks.

I have still some remarks or suggestions to avoid misunderstanding or confusion –

I suggest to write the interval range for parameters following this format (xx-yy unit) ex: (25-30 10-3 A).

 

Thank you for your suggestion! I have modified.

 

still some mistakes or comments :

- line 44 Zheng et al. instead of ZHENG

 

Thank you for your suggestion! I have modified.

 

- line 52-54 the numbers should be in subscript

 

Thank you for your suggestion! I have modified.

 

 –line 74-76 However, “most of them are the thermophysical parameters at room temperature. The thermophysical parameters of materials change with the change of temperature during the cladding process” should be replace with “most of them are at room temperature and change with the temperature during the cladding process”. sound better

 

Thank you very much! I have modified.

 

 - in my opinion the legends of figure are still not well described. for example figure 1.a what is it ?? on figure 2 what is the different image ? same sample ? same area…??? the figure 2 is not the distribution of the cracks but just some image of them. distribution will be related to the number of cracks over the area. The number on picture (fig 2) is related to what ?? clarify

 

For the question, figure 1.a shows the temperature distribution of the melt pool during cladding. the temperature range is marked on the figure, so I did not explain it. 1.b, 1.c and 1.d show the variation of the melt pool temperature when different parameters are taken for different values. The numbers on Figure 2 correspond to the numbers inside Table 4.

 

 - correct all the numbers (supscript format)

 

Thank you for your suggestion! I have modified.

 

- Again I will point out the lack of clarity of section 4.1 and 4.2. the section 4.1 should be introduce before in the main manuscript

 

For this question , 4.1 is the method of analysis, 4.2 and 4.3 are to use the method of 4.1. If put in front of the article is not coherent.

 

 - on table 5 what is the K value ?? it is not mention in the main text. is it R ? not clear

 

For the question, The K value is the sum of the experimental results at the corresponding level under each factor, and R is the maximum value of K minus the minimum value under each factor. The R value can be obtained by solving for K.

 

 - line 173 table 4 instead of Table 5

 

This is Table 4, Figure 2 is processed according to the parameters in Table 4.

 

 

- relation between and ？

I_i denotes the sum of the crack areal density corresponding to any column i level number.

 is the arithmetic mean of the crack areal density in any column.  is the average of I_i.

 

Figure 3 is “the influence of various factors on the R value of the crack rate”

 

Thank you for your suggestion! I have modified.

 

on line 186 correct the range 0.017~0.01 instead of 0.01-0.017. the ~ is not appropriate

 

Thank you for your suggestion! I have modified.

 

 

About references : some errors seem to be present but can not be checked as inaccessible. in Chinese instead of in China, [J] ?, space, subscript numbers,

some refs should be added :

https://doi.org/10.1186/s10033-021-00599-8

https://doi.org/10.3390/met1101005

 

Thank you for your suggestion! I have modified.

Author Response File: Author Response.docx