Thermo-Mechanical Coupling Numerical Simulation for Extreme High-Speed Laser Cladding of Chrome-Iron Alloy
Round 1
Reviewer 1 Report
1. Explain how did authors select parameters range as listed in Table 2 with supported references.
2. Error was found in the statement at page 4 line 148 ".....are displayed in Figure 1;...".
3. There is no explanation about the data obtained in Table 3 and 4 and how these data are used in work.
4. Explain how to measure the length and width of coating especially when the sticky powder phenomenon is serious.
5. In Figure 9, there is a discontinuous curve found in point C. Explain.
6. It is good to add explanation on the significant relationship between the temperature, microstructure and the resultant residual stress of coating.
Author Response
Response to Reviewer 1
Thank the reviewer for these important suggestions to help us revise this manuscript. These questions were explained and revised one by one in the new manuscript.
Question 1: Explain how did authors select parameters range as listed in Table 2 with supported references.
Response: Thank you for the comment. The selection of the range of process parameters was based on a summary of previous literature (Shen et al., 2020; Zheng et al., 2022) and a single-factor experimental design. The supported references 14 and 20 have been added to the article (Page 2, Line 96).
Question 2: Error was found in the statement at page 4 line 148 ".....are displayed in Figure 1;...".
Response: Thank you for the comment. The error in the statement at page 4, line 148, "...are displayed in Figure 1;..." has been revised at page 4, line 161: "...are displayed in Figure 2;..."
Question 3: There is no explanation about the data obtained in Table 3 and 4 and how these data are used in work.
Response: Thank you for the comment. The process of extreme high-speed laser cladding involves rapid melting, rapid cooling, and solidification of the material. Physical parameters such as material density, specific heat capacity, Young's modulus, coefficient of expansion, and yield strength vary considerably at different temperatures; therefore, temperature-dependent material parameter models are required to improve the accuracy of the thermo-mechanical coupling numerical simulation results. The thermal and mechanical material parameters from Tables 3 and 4 will be defined in the Abaqus finite element software, and the material parameters will be called upon when conducting thermal calculations for temperature and stress solutions. Information on how to use the data in Tables 3 and 4 has been added to the Material Parameter Model section (page 5, lines 194–196).
Question 4: Explain how to measure the length and width of coating especially when the sticky powder phenomenon is serious.
Response: Thank you for the comment. In order to observe the microstructure of the coatings and measure the width and height of the coatings, a 5 mm x 5 mm x 10 mm square specimen was cut out of the surface of a 45 steel shaft part by using the wire-cutting method, and the surface was cleaned of stains using alcohol, inlaid, ground, and polished. The width and height of the molten layer were observed and measured using an optical display, and when measuring the height and width of the coating, each value was measured three times and averaged. When the coating’s surface has the phenomenon of sticky powder, the powder particles are excluded when measuring the coating’s width and height dimensions. When carrying out the observation of the coating microstructure, the corrosion treatment was carried out using a 10% FeCl3 hydrochloric acid solution and a 4% HNO3 alcohol solution for 10 s each. After the corrosion was complete, the structure was observed using scanning electron microscopy or optical microscopy. The relevant methods and instructions have been refined for the revised paper (page 3, lines 100–112).
Question 5: In Figure 9, there is a discontinuous curve found in point C. Explain.
Response: Thank you for the comment. After rechecking the data, it was found that the reason for the curve discontinuity was due to improper software operation during the post-processing of the finite element data. The specific reason was that when the Abaqus software post-processed the exported data, two adjacent incremental steps of the adjacent analysis steps exported the same temperature data, resulting in a subsequent derivative calculation with a point where the data was zero, and therefore the cooling rate curve was not continuous. Figure 9 has been modified to the same position in the article (page 10, line 302).
Question 6: It is good to add explanation on the significant relationship between the temperature, microstructure and the resultant residual stress of coating.
Response: Thank you for the comment. An explanation of the significant relationship between temperature, structure, and residual stresses in coatings has been added to this section of the paper (page 11, lines 322–342, and page 12, lines 385–391).
Author Response File: 
Author Response.docx
Reviewer 2 Report
Title: Thermo-Mechanical Coupling Numerical Simulation for Extreme High-Speed Laser Cladding of Chrome-iron Alloy
* Abstract:” Maximum residual stress appears between the bonding region of the coatings and the substrate, and the coatings themselves have significant residual stress in the form of tensile strains that are mostly distributed in the direction of the laser cladding speed.”: should be in the direction of laser cladding.
* Introduction:’.. residuals of the fused coating..’: please explain.
* Materials and Methods: ‘..corroded in..’: Should be etched. The numerical calculation of residual stress can be elaborated.
* Results and Discussion: Please elaborate more on the effect of laser power, cladding speed, powder feed rate on the surface condition/ defects of the coating. Figure 11 can be clearer. Figures 8, 9 and 11 must be correlated. Figures 8, 12 and 13 should be linked. How did you determine the stress, the black line, in Figure 13?
* Conclusions can be changed.
* English can be enhanced. '..Chrome-iron..': can be Chrome-Iron.
Author Response
Response to Reviewer 2
Thank the reviewer for these important suggestions to help us revise this manuscript. These questions were explained and revised one by one in the new manuscript.
Question 1: Abstract:” Maximum residual stress appears between the bonding region of the coatings and the substrate, and the coatings themselves have significant residual stress in the form of tensile strains that are mostly distributed in the direction of the laser cladding speed.”: should be in the direction of laser cladding
Response: Thank you for the comment. The expression "in the direction of laser cladding" was found to be more academic and accurate by consulting relevant books and literature. The results have been corrected in the paper (page 1, line 22).
Question 2: Introduction:’.. residuals of the fused coating..’: please explain.
Response: Thank you for the comment. I sincerely apologize for the error in the paper's drafting and the missing words that led to a misunderstanding. The phrase "residual stresses in fused coatings" is what I really meant. The expression has been corrected in the paper (page 2, line 84).
Question 3: Materials and Methods: ‘..corroded in..’: Should be etched. The numerical calculation of residual stress can be elaborated.
Response: Thank you for the comment. When describing the method that was used in the experiment, the term "etched" is more appropriate. However, I have extensively rewritten this section to better describe the method of experimentation.
The numerical calculation of residual stress has been elaborated on in the paper (page 5, lines 175–182).
Question 4: Please elaborate more on the effect of laser power, cladding speed, powder feed rate on the surface condition/ defects of the coating.
Response: Thank you for the comment. More discussion on the effect of laser power, cladding speed, and powder feed rate on the surface condition and defects of the coating has been added to the paper (pages 7-8, lines 244–253).
Question 5: Figure 11 can be clearer.
Response: Thank you for the comment. Figure 11 has been replaced by a more clear picture (page 11, line 343).
Question 6: Figures 8, 9 and 11 must be correlated.
Response: Thank you for the comment. The relationship between Figures 8, 9, and 11 has been further analyzed in the paper (page 11, lines 309–316, and page 12, lines 317–342).
Question 7: Figures 8, 12 and 13 should be linked.
Response: Thank you for the comment. Figures 8, 12, and 13 have been linked to the analysis of the relationship between temperature gradients and residual stresses (page 12, lines 385–391).
Question 8: How did you determine the stress, the black line, in Figure 13?
Response: Thank you for the comment. The residual stress is mainly determined by the black curve; the other three physical quantities represent stresses in different directions; and the direction and area where the coating is most prone to cracking are determined by the maximum stress component.
Question 9 : Conclusions can be changed.
Response: Thank you for the comment. New analysis results have been added to the conclusion (page 14, lines 406-408).
Question 10: English can be enhanced. '..Chrome-iron..': can be Chrome-Iron.
Response: Thank you for the comment. The title of the paper has been changed '. Chrome-iron...' into" Chrome-Iron"
Author Response File: Author Response.docx
Reviewer 3 Report
The paper is not complete, even if it could potentially be a good work. It needs to be improved with following major revisions:
1. Please clarify the needs of the study, why this paper is written (be more specific). What is the different in this paper from the previous studies, what is added value of this paper? What is your contribution? Provide this at the end of Introduction part.
2. The literature review in Introduction part should be extended to to provide a big picture on this topic. Therefore, the literature review must be extended to cover application and the most recent literature. I suggest the following litereature:
“Laser cladding and applications”, Sustainable Engineering and Innovation, vol. 5, no. 1, pp. 1-14, Feb. 2023.;
“Comparison of mechanical and microstructure properties of tungsten alloys for special purposes”, Sustainable Engineering and Innovation, vol. 4, no. 2, pp. 191-197, Dec. 2022.;
“Structural materials: fire and protection”, Heritage and Sustainable Development, vol. 4, no. 2, pp. 134–144, Dec. 2022.
Modelling the effect of feed rate on residual stresses induced due to milling using experimental and numerical methods, Periodicals of Engineering and Natural Sciences, Vol 9, No 3, pp.76-81, 2021.
3. The results should be compared with similar studies from the literature, by providing coherent and incoherent points.
4. I believe the submitted paper can only be acceptable after the correcting and/or adding the required points mentioned above for the publication in the journal.
Author Response
Response to Reviewer 3
Thank the reviewer for these important suggestions to help us revise this manuscript. These questions were explained and revised one by one in the new manuscript.
Question 1: Please clarify the needs of the study, why this paper is written (be more specific).
Response: Thank you for the comment. This paper establishes a thermodynamic coupled finite element model based on experimental parameters to predict the temperature and residual stress during the melting process and provide guidance for process optimization. The needs and reasons for writing this paper have been supplemented in the introduction (page 1, lines 40–44, and page 2, lines 71–77).
Question 2: What is the different in this paper from the previous studies?
Response: Thank you for the comment. Conventional laser melting is relatively mature, but ultra-high-speed laser melting mainly focuses on coating performance comparison and performance testing, and there is relatively little influence on coating performance due to temperature change in the melting process. Compared with the previous work, this paper establishes the relationship between temperature, microstructure, and mechanical properties of the melted coating based on the finite element method. (page2,lines74-77)
Question 3: What is added value of this paper?
Response: Thank you for the comment. The added value of this paper is to provide a relatively accurate numerical model for predicting temperature variations in the melting process for the development of new coating materials, and to provide guidance for reducing coating cracking.
Question 4: What is your contribution? Provide this at the end of Introduction part.
Response: Thank you for the comment. Our contribution has been revised to the paper (page 2, lines 78–84).
Question 5: The literature review in Introduction part should be extended to to provide a big picture on this topic. Therefore, the literature review must be extended to cover application and the most recent literature. I suggest the following litereature:
“Laser cladding and applications”, Sustainable Engineering and Innovation, vol. 5, no. 1, pp. 1-14, Feb. 2023.;
“Comparison of mechanical and microstructure properties of tungsten alloys for special purposes”, Sustainable Engineering and Innovation, vol. 4, no. 2, pp. 191-197, Dec. 2022.;
“Structural materials: fire and protection”, Heritage and Sustainable Development, vol. 4, no. 2, pp. 134–144, Dec. 2022.
Modelling the effect of feed rate on residual stresses induced due to milling using experimental and numerical methods, Periodicals of Engineering and Natural Sciences, Vol 9, No 3, pp.76-81, 2021.
Response: Thank you for the comment. I have carefully read and thought about the literature you recommended, which has given me a clearer understanding of laser cladding technology applications, the selection of cladding materials, numerical simulation methods, and other issues. The literature review in the Introduction part has been extended (page 1, lines 30, 32, and 44). The relevant literature has been cited in references 2, 4, 5, and 11.
Question 6: The results should be compared with similar studies from the literature, by providing coherent and incoherent points.
Response: Thank you for the comment. The results have been revised by comparing them with similar studies from the literature and updated in the paper. (page 6, lines 207–209, lines 216-220; page 7, lines 228–230; page 9, lines 287–290, lines 298–300; page 10, lines 309–315)
Author Response File: Author Response.docx
Reviewer 4 Report
The work deals with a highly interesting topic as high-speed cladding is becoming a method for fast and high-performance coating, replacing less sustainable processes such as hard chrome plating. The research question is appropriate as it seeks to investigate the stress state following the thermal laser process. However, the work has two serious methodological weaknesses that suggest the authors revise their approach before resubmitting. Firstly, the "one-factor-at-a-time" approach in experimentation is highly debatable as it does not highlight the interactions between input factors, which the literature suggests are significant. Secondly, studying and simulating only one pass in surface cladding (which requires multiple passes) is methodologically limited. Therefore, it is suggested that the authors design a better experimental plan and conduct a comprehensive validation that includes the simulation output: temperature and residual stresses for more than one condition.
English is appropriate for not mother tongue
Author Response
Response to Reviewer 4
Thank the reviewer for these important suggestions to help us revise this manuscript. These questions were explained and revised one by one in the new manuscript.
Question 1: The "one-factor-at-a-time" approach in experimentation is highly debatable as it does not highlight the interactions between input factors, which the literature suggests are significant.
Response: Thank you for the comment.
The main influencing factors of ultra-high-speed laser cladding technology are laser power, powder feeding rate, laser cladding rate, and coating lap rate. The use of single-factor experiments to study the process parameters does have some design flaws. However, due to the late start of ultra-high-speed laser cladding, many process parameters are in the blank stage. The single-factor experimental method to study the influence of different process parameters on the clad coating can determine the influence of each factor on the clad coating more accurately, determine the range of action of different parameters, and provide a parameter basis for the orthogonal experimental design of ultra-high-speed laser cladding.
In addition, the height of the melt pool of ultra-high-speed laser cladding is generally less than 300 μm and the heat-affected zone is generally less than 50 μm, which makes it difficult to experimentally observe and determine the melt pool temperature change and residual stress distribution characteristics during the cladding process. The focus of this paper is to obtain a set of relatively optimal melting parameters, perform numerical modeling, obtain the temperature change during the melting process, predict the residual stress, analyze the bond strength and cracking tendency of the coating, and provide guidance for the optimization of the ultra-high-speed laser melting process and the reduction of residual stress to avoid coating cracking.
Moreover, the prediction model between temperature, microstructure, and residual stresses established by numerical simulation is an important guideline for the quantitative study of the relationship between temperature variation and microstructure. The established numerical models are of great transferability for developing new coating materials and evaluating the bond strength and residual stresses of new material coatings.
Question 2: Studying and simulating only one pass in surface cladding (which requires multiple passes) is methodologically limited.
Response: Thank you for the comment. For coating manufacturing technology, it is essential to perform multiple laps. Your comments are the next step in my experimental program. However, my current research goal is to establish a single-pass simulation model for ultra-high-speed laser cladding to predict the temperature change during the cladding process and the residual stress distribution after the cladding, and to provide a research basis and process reference for multi-pass lap joining. Although the research method of single-pass melting has some limitations, the numerical simulation can effectively predict the temperature change during the melting process and provide reference significance to avoid over burning during the melting process.
In the next step, I will further conduct experiments and numerical simulations of multi-lap cladding to analyze the action law.
Question 3: It is suggested that the authors design a better experimental plan and conduct a comprehensive validation that includes the simulation output: temperature and residual stresses for more than one condition.
Response: Thank you for the comment. The purpose of this paper is the preliminary stage of combining process experiments and numerical simulation experiments, mainly to establish a thermodynamic coupling model to predict the temperature and stress fields. In the next experiment, I will conduct an orthogonal experimental design to analyze the effects of multiple factors on the melting temperature and stress fields.
Author Response File: Author Response.docx
Round 2
Reviewer 4 Report
Although some doubts remain about the very preliminary nature of the work (which only addresses a single pass and studies the effect of parameters one by one), given the interest in the topic and the candid feedback from the authors, the paper can be published as is.
Overall, the work is written in satisfactory English, especially for non-native readers. However, a review by a native English speaker would further improve its readability.
