Microstructure and Performance of Fe50Mn30Cr10Ni10 High-Entropy Alloy Produced by High-Efficiency and Low-Cost Wire Arc Additive Manufacturing
, Yongle Hu 1, Xiubing Liang 2,*, Yongxiong Chen 2, Kaiming Wang 1, Mingjun Zhang 1 and Jiaguo Xu 1
Round 1
Reviewer 1 Report
The paper looks interesting and can be published after addressing the following comments:
1) The introduction is too short. Specifically, I encourage authors to discuss the issue of “anisotropy” in additively manufactured components. This will add to the Introduction section. Examples of recent works are:
a) For the effects on material anisotropies, see: Anisotropy and heterogeneity of microstructure and mechanical properties in metal additive manufacturing: A critical review. Materials & Design. 2018 Feb 5;139:565-86.
b) For the effects on fatigue performance, see: A generalized criterion for fatigue crack growth in additively manufactured materials–Build orientation and geometry effects. International Journal of Fatigue. 2021 Apr 1;145:106099.
c) For the effects on microstructure, see: Functionally graded Inconel 718 processed by additive manufacturing: Crystallographic texture, anisotropy of microstructure and mechanical properties. Materials & Design. 2017 Jan 15;114:441-9.
2) In Fig. 4b, can you explain why the strain hardening rate has the unit of MPa? And why it goes that high up to 80000 MPa?
3) Vertical axis legend on Fig. 6c is not clear.
Author Response
Reviewer #1: The paper looks interesting and can be published after addressing the following comments:
- The introduction is too short. Specifically, I encourage authors to discuss the issue of “anisotropy” in additively manufactured components. This will add to the Introduction section. Examples of recent works are:
- For the effects on material anisotropies, see: Anisotropy and heterogeneity of microstructure and mechanical properties in metal additive manufacturing: A critical review. Materials & Design. 2018 Feb 5;139: 565-86.
- For the effects on fatigue performance, see: A generalized criterion for fatigue crack growth in additively manufactured materials–Build orientation and geometry effects. International Journal of Fatigue. 2021 Apr 1;145:
- For the effects on microstructure, see:Functionally graded Inconel 718 processed by additive manufacturing: Crystallographic texture, anisotropy of microstructure and mechanical properties. Materials & Design. 2017 Jan 15; 114: 441-9.
Response: Thanks the reviewers’ comments. The previous researches showed that the contributing factors to the anisotropy and heterogeneity are the unique microstructural features or manufacturing deficiencies. Meanwhile, the mechanical properties were significant different in different direct and primarily dependent on the grain size and texture. We highly agree with the reviews’ idea and have supplemented the discussion of the issue for “anisotropy” in additively manufactured components and revised the references. Please see the revised manuscript for details.
- In Fig. 4b, can you explain why the strain hardening rate has the unit of MPa? And why it goes that high up to 80000 MPa?
Response: From the true stress-true strain curve of the high-entropy alloy shown in Fig. 4(a), it can be seen that the strength of the alloy increases significantly with increasing deformation, which indicates the existence of strain-hardening behavior during deformation. In this paper, the strain hardening rate (dσt/dξt) of this alloy during loading was calculated using the following equation:
σt--true stress(MPa); ξt--true strain; n-- hardening index.
From the formula, the unit of strain hardening rate is MPa, and the value is the quotient of true stress and true strain multiplied by the work hardening index, so it will reach 8000 MPa.
- Vertical axis legend on Fig. 6c is not clear.
Response: We have modified the diagram as you requested, the details can be seen in revised manuscript.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Manuscript ID: lubricants-2026334
Type of manuscript: Article
Title: Microstructure and performance of Fe50Mn30Cr10Ni10 high-entropy alloy produced by high-efficiency and low-cost wire arc additive manufacturing
Dear Ms. Faye Yin
Assistant Editor of Lubricants
In this manuscript, the authors developed a wire arc additive manufacturing (WAAM) method to produce the Fe50Mn30Cr10Ni10 high-entropy alloy. They investigated the microstructure, mechanical properties and corrosion resistance of the prepared alloy. The results showed that the as-produced alloy is composed of a FCC phase with a minor σ phase with a dendritic microstructure. Also, the mechanical and corrosion behavior of the alloy was acceptable. I think that this manuscript can be interesting for the reader of Lubricants. Therefore, it can be accepted after a minor revision.
-Comment:
The whole manuscript should be revised by a English native. There are several problems in the text that need to be corrected, and the following two are just examples:
“Herein, we developed a wire arc additive manufacturing (WAAM) method with high-efficiency and low-cost and Fe50Mn30Cr10Ni10 high-entropy alloy was successfully produced.”
“304 SS with a size of substrate was 200×100×10 mm was used as substrate.”
Author Response
Reviewer #2: The whole manuscript should be revised by a English native. There are several problems in the text that need to be corrected, and the following two are just examples:
“Herein, we developed a wire arc additive manufacturing (WAAM) method with high-efficiency and low-cost and Fe50Mn30Cr10Ni10 high-entropy alloy was successfully produced.”
“304 SS with a size of substrate was 200×100×10 mm was used as substrate.”
Response: Thanks for the reviewers' comment. We tried our best to improve the English expression. We hope the revised version can meet the standard of the journal.
Author Response File: Author Response.docx
Reviewer 3 Report
Authors have deposited HAE using WAAM processes. Though WAAM of HEA is a topic on interest, the manuscript in its current form lacks several details including benchmarking of deposited samples, making it difficult to assess the quality and novelty of the work. It is recommended to benchmark the mechanical performance of HEA with the conventional one. Apart from this below are the other remarks:
1. “we prepared Fe50Mn30Co10Cr10 (HEA) wire material” How was the wire prepared?
2. “it can be seen that the grain size gradually decreases from the bottom to the top, which may be related to the heat dissipation of the surface”. Typically cooling rate is faster at the bottom and slow at top leading to coarsening of microstructure at the top (https://doi.org/10.1016/j.addma.2018.06.020). However, authors arguments were otherwise. Authors need to justify their observation properly.
3. Authors need to provide the following details:
a) Image of experimental setup
b) Cross-sectional image of the deposition, identifying the various zones from which microstructure was investigated.
c) What are the process parameters used in the present study? How are they arrived?
4. EDS results from area mapping should be supported with point EDS results. Currently the area mapping looks too coarse and deriving conclusions based on it may not be appropriate.
5. What is the rational in comparing corrosion behaviour of HEA with 45 steel?
6. Though the study looks interesting it is neither bench marked with conventional HEA nor with depositions with different process parameters. The study lacks scientific approach in terms of benchmarking.
7. It is recommended to benchmark the performance with standard HAE of similar composition.
Author Response
Reviewer #3: Authors have deposited HAE using WAAM processes. Though WAAM of HEA is a topic on interest, the manuscript in its current form lacks several details including benchmarking of deposited samples, making it difficult to assess the quality and novelty of the work. It is recommended to benchmark the mechanical performance of HEA with the conventional one. Apart from this below are the other remarks:
- “we prepared Fe50Mn30Co10Cr10 (HEA) wire material” How was the wire prepared?
Response: Thanks for the reviewers' comment. We have added a method for the preparation of HEA welding wire, the details can be seen in revised manuscript.
- “it can be seen that the grain size gradually decreases from the bottom to the top, which may be related to the heat dissipation of the surface”. Typically cooling rate is faster at the bottom and slow at top leading to coarsening of microstructure at the top (https://doi.org/10.1016/j.addma.2018.06.020). However, author arguments were otherwise. Authors need to justify their observation properly.
Response: According to the report in Rf. [1], The shape of the crystal grain is related to the temperature gradient Tg, the solidification rate R, the degree of subcooling ∆T, and the diffusion coefficient DL during the solidification of the melt. According to the different relationship of Tg, R, ∆T and DL, When Tg/R>∆T/DL, the crystal has a columnar structure, when Tg/R<△T/DL, the crystal has a plane equiaxed structure. The center temperature of the molten pool is high, the temperature gradient Tg is the largest, the temperature at the edge position is low, and the edge position speed is much greater than the center of the molten pool during heat dissipation, so the edge solidification rate R and the degree of subcooling ∆T are relatively large. Therefore, from the center to the edge of the molten pool, Tg/R gradually decreases, △T/DL gradually increases, and the crystal grains gradually transform from dendritic to equiaxed. We have modified the manuscript and the details can be seen in revised manuscript.
- Authors need to provide the following details:
- Image of experimental setup
- Cross-sectional image of the deposition, identifying the various zones from which microstructure was investigated.
- What are the process parameters used in the present study? How are they arrived?
Response: Thanks to the reviewer. We have provide the details in revised manuscript.
- EDS results from area mapping should be supported with point EDS results. Currently the area mapping looks too coarse and deriving conclusions based on it may not be appropriate.
Response: We agree with the reviewer that EDS results from area mapping should be supported with point EDS results. We have added the point EDS results in Table 2 in the revised version.
- What is the rational in comparing corrosion behavior of HEA with 45 steel?
Response: Thanks to the reviewers. 45 steel is a medium carbon steel with a carbon content of 0.4% or more, which is a widely used high quality carbon structural steel. However, its corrosion resistance is poor. Therefore, a material with better corrosion resistance has been developed to expand its application. Therefore, 45 steel was chosen for the comparison of corrosion resistance.
- Though the study looks interesting it is neither bench marked with conventional HEA nor with depositions with different process parameters. The study lacks scientific approach in terms of benchmarking.
Response: We agree with the reviewers that benchmarking with conventional HEA and deposition of different process parameters would give the paper a scientific approach in terms of benchmarking. So we add the comparison of the fracture elongation-yield strength. The details can be seen in Fig. 5(c) in revised manuscript.
- It is recommended to benchmark the performance with standard HAE of similar composition.
Response: We agree with the reviewers that benchmarking with standard HAE of similar composition would give the paper a scientific approach in terms of benchmarking. However, currently, most of the high entropy alloys are cast by melting, which is difficult to achieve heterogeneous shaped parts, and also the size of the parts is limited. In this work, we try a new method of arc additive, which is more efficient draft and less costly compared with the traditional method. Therefore, we explored and studied the feasibility of this method. Meanwhile, in later studies, we will systematically investigate the effect of different compositions on performance.
[1] Q. Wang, Y. Li, J. Zhu, M. F. Li, Z. X. Men, Extreme High Speed Laser Cladding 316L Coating. Journal of Physics: Conference Series 2021, 1965 (1), 012083. https://doi.org/012083. 10.1088/1742-6596/1965/1/012083.
Author Response File: Author Response.docx
Round 2
Reviewer 3 Report
The authors have addressed all the queries raised by the reviewer. Therefore, I suggest it for publication.
