Impact of Temperature on the Tensile Properties of Hypereutectic High-Entropy Alloys
Round 1
Reviewer 1 Report
The follwoing points need to be adressed in the revised manuscript:
-What is the significance of the Orowan by-passing mechanism in the tensile properties of hypereutectic high-entropy alloys?
-How does the presence of both soft L12 and hard BCC (B2) phases affect the fracture modes of hypereutectic high-entropy alloys?
-What are the potential applications of hypereutectic high-entropy alloys with ordered L12 and BCC phases in the field of materials science?
-How do the results of this study contribute to the understanding of the mechanical behavior of hypereutectic high-entropy alloys?
-What are the implications of the study's findings for the development of new high-entropy alloys with improved mechanical properties?
-Are there any limitations to the study's methodology or results that should be taken into account when interpreting the conclusions?
-How do the conclusions of this study compare to previous research on the mechanical properties of hypereutectic high-entropy alloys?
-Please expand the reference part by reviewing more relevant papers. The following refs are just recommendations:
[a] Journal of Alloys and Compounds 770 (2019): 655-661
[b] Journal of Alloys and Compounds 954 (2023): 170091
[c] Intermetallics 143 (2022): 107476
Author Response
Comments 1: What is the significance of the Orowan by-passing mechanism in the tensile properties of hypereutectic high-entropy alloys?
Response 1: When the dislocations approach the precipitates, they start to curve around the non-deformable particles. Under sufficient applied stress, dislocations may move across the precipitates, leaving behind Orowan loops around the particles (Fig. 10a). Dislocation movement can be impeded by the B2 precipitates, thereby improving the strength for the -100-alloy and RT-alloy.
Comments 2: How does the presence of both soft L12 and hard BCC (B2) phases affect the fracture modes of hypereutectic high-entropy alloys?
Response 2: At room temperature, the deformation of FCC and BCC(B2) phases is asynchronous, the BCC phase is much harder than the FCC phase. Due to the weaker deformability property of BCC(B2) phase, shear bands and shear fractures are observed in the BCC (B2) phases due to shearing stress concentration. Therefore, the RT-alloy shows a mixture of trench-like (BCC (B2)) and dimples morphology (L12 phase). Ductile fracture in the L12 phase and brittle-like fracture in the BCC(B2) phase.
However, under high temperatures, the BCC (B2) phase undergoes softening, and both the L12 and BCC (B2) phases experience severe plastic deformation. Numerous dimples are observed, indicating ductile fracture.
Comments 3: What are the potential applications of hypereutectic high-entropy alloys with ordered L12 and BCC phases in the field of materials science?
Response 3: The eutectic high-entropy alloys (EHEAs) with a mixture of soft FCC and hard BCC (B2) phases can achieve the balance of high strength and ductility. From previous reports, AlCoCrFeNiNi2.2 hypereutectic high-entropy alloy contains more primary FCC phases. Therefore, the ductility of AlCoCrFeNiNi2.2 hypereutectic high-entropy alloy is superior to that of AlCoCrFeNi2.1 eutectic high-entropy alloy. Moreover, it is believed that Al atom in AlCoCrFeNi-based alloys can lead to the formation of BCC(B2) phase. Therefore, the hypereutectic high-entropy alloys perform outstanding strength and excellent ductility simultaneously. The above advantages make it clear that there is great potential for its application in the field of structural materials.
The state and explanation have been added in the introduction section and highlighted.
Comments 4: How do the results of this study contribute to the understanding of the mechanical behavior of hypereutectic high-entropy alloys?
Response 4: Hypereutectic alloy prepared by increasing the Al content has been scarcely investigated. Moreover, the influence of primary FCC phases and B2 precipitate phases on the tensile properties of hypereutectic alloys in a wide temperature range has seldom been studied. Therefore, a novel hypereutectic Al1.1CoCrFeNi2.1 high-entropy alloy is prepared. This study presents a detailed discussion on the microstructure evolution and mechanical properties in a wide temperature range.
The Al1.1CoCrFeNi2.1 hypereutectic high-entropy alloy contains more primary FCC phases. Therefore, the ductility of the alloy is superior to that of AlCoCrFeNi2.1 eutectic high-entropy alloy. However, the presence of a large number of cracks near the spherical primary L12 phase significantly reduces the ductility and strength at high temperatures. Therefore, the hypereutectic Al1.1CoCrFeNi2.1 exhibits superior plasticity and strength properties at low tensile temperatures (-100 °C, 23±2 °C) than the high tensile temperatures.
The state and explanation have been added in the abstract and introduction sections and highlighted.
Comments 5: What are the implications of the study's findings for the development of new high-entropy alloys with improved mechanical properties?
Response 5: Single-phase High entropy alloys (HEAs) have limitations, such as poor castability and component segregation. In addition, the commonly reported single-phase high-entropy alloys can only exhibit higher strength or higher ductility, and it is difficult to achieve a balance of strength and toughness. Eutectic high-entropy alloys (EHEAs), which contain a mixture of soft FCC and hard BCC phases, can achieve a balance of high strength and ductility, as well as excellent castability.
The Al1.1CoCrFeNi2.1 hypereutectic high-entropy alloy contains more primary FCC phases, which ensure excellent ductility. Moreover, Al atom in AlCoCrFeNi-based alloys can lead to the formation of hard BCC (B2) phase. Therefore, the hypereutectic high-entropy alloys perform outstanding strength and excellent ductility simultaneously. The findings of the article provide a new approach to enhancing the comprehensive mechanical properties of hypereutectic alloys.
The state and explanation have been added in the introduction and abstract sections and highlighted.
Comments 6: Are there any limitations to the study's methodology or results that should be taken into account when interpreting the conclusions?
Response 6: Thank you for pointing this out. In this article, we just consider limited low tensile temperatures (-100 °C, 23±2 °C). It is uncertain whether the alloy still possesses excellent strength and ductility at other low temperatures. Therefore, more tensile temperatures should be considered in the future.
Comments 7: How do the conclusions of this study compare to previous research on the mechanical properties of hypereutectic high-entropy alloys?
Response 7: There have been numerous studies on hypereutectic high-entropy alloys. However, the influence of the primary FCC phase and B2 precipitate phase on the tensile properties of hypereutectic alloys has seldom been studied in a wide temperature range, especially when preparing these alloys by increasing the Al content.
The Al1.1CoCrFeNi2.1 hypereutectic high-entropy alloy contains more primary soft FCC phases, which ensure excellent ductility. Moreover, the interaction of the B2 phase and dislocations triggers the Orowan bypass mechanism, thereby contributing to the excellent strength of the alloy. Therefore, compared to other reported hypereutectic high entropy alloys, the alloy studied in this work demonstrates comprehensive mechanical performance advantages.
The state and explanation have been added in the introduction, conclusions and section 4.2 (third paragraph).
Comments 8: Please expand the reference part by reviewing more relevant papers. The following refs are just recommendations:
[a] Journal of Alloys and Compounds 770 (2019): 655-661
[b] Journal of Alloys and Compounds 954 (2023): 170091
[c] Intermetallics 143 (2022): 107476
Response 8: The citations mentioned above have been added in the introduction section.
Reviewer 2 Report
Manuscript Number: coatings-2678006
Title: Temperature on tensile properties for a hypereutectic high-entropy alloy
Coatings (ISSN 2079-6412)
After reading your manuscript, I think the topic is relevant for the journal and there are several experiments included. This article shows some promise for publication. In order to justify the publication of this work a Major improvement has to be made in terms of the following remarks:
- The wording must be improved throughout. The authors should work with an English-speaking colleague and consider resubmission only after a careful edit.
· Title: The title of the article is not appropriate, it should be revised. here are some alternative titles for your paper:
“Impact of Temperature on the Tensile Properties of Hypereutectic High-Entropy Alloy”
“Exploring the Temperature Dependence of Tensile Properties in Hypereutectic High-Entropy Alloy”
“Thermal Influence on the Tensile Behavior of Hypereutectic High-Entropy Alloy”
“Temperature-Induced Variations in the Tensile Properties of Hypereutectic High-Entropy Alloy”
“Understanding the Role of Temperature in the Tensile Strength of Hypereutectic High-Entropy Alloy”
Remember, a good title should accurately represent the content of your paper while also attracting readers. Choose the one that best fits your research!
· Acronyms like SEM, XRD, TEM ... should be introduced in the first time of use. See the Materials and Methods section.
· The introduction of testing techniques and methods needs to be articulated more precisely.
- Were samples Au-sputter-coated for the SEM study?
· The room temperature should be noted in the manuscript, for example, 23±2 °C.
· In a separate section, your work outcomes should be compared with recent similar research.
· Please also be sure that your abstract and your Conclusions section not only summarize the key findings of your work but also explain the specific ways in which this work fundamentally advances the field relative to prior literature.
- The wording must be improved throughout. The authors should work with an English-speaking colleague and consider resubmission only after a careful edit.
Author Response
After reading your manuscript, I think the topic is relevant for the journal and there are several experiments included. This article shows some promise for publication. In order to justify the publication of this work a Major improvement has to be made in terms of the following remarks:
Comments 1: The wording must be improved throughout. The authors should work with an English-speaking colleague and consider resubmission only after a careful edit.
Response 1: We have checked the text, and some syntax and grammar mistakes have been revised. The revised text has been highlighted.
Comments 2: The title of the article is not appropriate; it should be revised. Here are some alternative titles for your paper:
“Impact of Temperature on the Tensile Properties of Hypereutectic High-Entropy Alloy”
“Exploring the Temperature Dependence of Tensile Properties in Hypereutectic High-Entropy Alloy”
“Thermal Influence on the Tensile Behavior of Hypereutectic High-Entropy Alloy”
“Temperature-Induced Variations in the Tensile Properties of Hypereutectic High-Entropy Alloy”
“Understanding the Role of Temperature in the Tensile Strength of Hypereutectic High-Entropy Alloy”
Remember, a good title should accurately represent the content of your paper while also attracting readers. Choose the one that best fits your research!
Response 2: Thank you for pointing this out. I agree with this comment. The title of the article has been revised: Impact of Temperature on the Tensile Properties of Hypereutectic High-Entropy Alloy
Comments 3: Acronyms like SEM, XRD, TEM ... should be introduced in the first time of use. See the Materials and Methods section. The introduction of testing techniques and methods needs to be articulated more precisely.
Response 3: The acronyms like SEM, XRD, TEM ... have been introduced in section 2. The detailed testing techniques and methods have been described in the article (section 2).
Comments 4: Were samples Au-sputter-coated for the SEM study?
Response 4: The experimental samples have good electrical conductivity, and can be clearly observed. Therefore, no Au-sputter-coated during SEM analysis.
Comments 5: The room temperature should be noted in the manuscript, for example, 23±2 °C.
Response 5: Thank you for pointing this out. The room temperature has been noted in the manuscript (section 2.2).
Comments 6: In a separate section, your work outcomes should be compared with recent similar research.
Response 6: Thank you for pointing this out. The outcomes have been compared with recent similar research.
There have been numerous studies on hypereutectic high-entropy alloys. However, hypereutectic alloy prepared by increasing the Al content has been scarcely investigated. Moreover, the influence of primary soft FCC phase and B2 precipitate phase on the tensile properties of hypereutectic alloys in a wide temperature range has seldom been studied.
The Al1.1CoCrFeNi2.1 hypereutectic high-entropy alloy contains more primary soft L12 phases, which ensure excellent ductility. Moreover, it is believed that Al atom in AlCoCrFeNi-based alloys can lead to the formation of B2 precipitate phases, and the interaction of the B2 phase and dislocations triggers the Orowan bypass mechanism, thereby contributing to the excellent strength of the alloy. Therefore, compared to other reported hypereutectic high entropy alloys, the alloy studied in this work demonstrates comprehensive mechanical performance advantages.
The state and explanation have been added in the introduction and section 4.2 (third paragraph).
Comments 7: Please also be sure that your abstract and your Conclusions section not only summarize the key findings of your work but also explain the specific ways in which this work fundamentally advances the field relative to prior literature.
Response 7: Thank you for pointing this out. The Al1.1CoCrFeNi2.1 hypereutectic high-entropy alloy contains more primary soft L12 phases, which ensure excellent ductility. Moreover, the Orowan by-passing mechanism caused by the B2 precipitates increases the strength for low-temperature tensile tests (-100 °C and 23±2 °C). The results show that the hypereutectic Al1.1CoCrFeNi2.1 exhibits superior plasticity and strength properties at low temperatures. The findings of the article provide a new approach to enhancing the comprehensive mechanical properties of hypereutectic alloys.
The state and explanation have been added in the abstract section.
Round 2
Reviewer 1 Report
The revision is acceptable.
Reviewer 2 Report
Accept
