Particle Stimulated Nucleation Effect for Al-Mg-Zr-Sc Alloys with Ni Addition during Multidirectional Forging

Round 1

Reviewer 1 Report

The manuscript describes how alloys based on Al-Mg-Ni-Sc-Zr with different content of Al3Ni particles were deformed by MDF at a temperature of 350 °C and how this affected their structure and properties. The paper reported that the Al3Ni particles helped create a finer and more uniform grain structure, while the Al3(Sc, Zr) particles ensured its stability. The authors conclude that the mixture of nano- and microparticles gave the best results.

Author Response

Response to review for metals-2528537, adressed to Reviewer 1.

 

Dear Reviewer ,

 

We are applicate for the high grades of our work.

Thank you for your consideration. I look forward to hearing from you.

 

Sincerely,

Anastasia Mikhaylovskaya on behalf of all co-authors.

E-mail: [email protected]

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments to the Authors on "An improvement of grain refinement effect and mechanical properties due to multidirectional forging for Al-Mg-based alloys with Ni, Sc, and Zr."

In this manuscript, the authors report their attempt at improving the mechanical properties of Al-Mg alloy with minor added Ni, Sc, and Zr. Among them, the authors fabricated the ultrafine grained materials using the multiple directional forging (MDF) processes and the particle-stimulated nucleation at the Al₃Ni particles. The authors especially focus on the effect of the volume fraction of Al₃Ni based on the different amounts of Ni addition. The reviewer comments on the manuscript as follows.

It is well-understood an improvement of the mechanical properties in the Al-Mg alloys in this manuscript. However, the manuscript is further improved with the typical figures showing the relationship between the Al₃Ni and PSN phenomena from a scientific standpoint. The reviewer expects that Figure 7 is one of the keys in this manuscript. Although the authors explained the Al₃(Sc, Zr) well, more description of the Al₃Ni and related PSN needs more. The reviewer suggests that the authors describe the grain refinement process in detail. For achievement, the authors should take additional images and figures. Besides, the reviewer recommends adding the schematic illustration of the process of grain refinement and PSN.

 

Minor Comments

1. Why don't the authors explain the materials process, including the MDF process described in L.102 is also first, before the characterization technique in the Materials and Methods section? Additionally, Table 1 should be set at the beginning or bottom of the Page.

2. In Figure 1, Details of the Al₃Ni particle are explained and added, then the story would be easy to understand for the readers; the white character on the white-based image does not match to see.

3. In Figure 2, Is it possible to revise the S-S curve as the horizontal axis of the cumulative strain, which is similar to Fig.1 in the following paper?

Miura and Nakamura, Philos. Mag. Lett., 63(2013), 601 (http://dx.doi.org/10.1080/09500839.2013.827800).

4. In Figure 5, Why don't you use the KAM maps? The reviewer expects that it is suitable to show the deformed and recrystallized grain structure.

5. In Figure 6, the horizontal axis of the real number is better than the log. Why did the authors use the log axis?

6. In Figure 7, The reviewer guesses the intensity of superlattice spots is increasing with increasing of the ordered precipitates. Please compare the diffraction patterns of (g) to (I), and explain the intensity of the superlattice spots. Also, can the authors use the diffraction pattern taken from <110> in (h)?

7. Why don't the authors use the S-S curves but a table to describe Mechanical properties?

8. There are many mistakes, like typos, in the manuscript. The reviewer recommends revising the manuscript thoroughly by the authors. Some example is suggested as follows.

8-1. L53: "p" is P? Or it seems not to be a single paragraph?

8-2. L.89: "energy dispersive detector" is energy dispersive "spectroscopy." The technique should be explained, as well as the facilities.

8-3. L.99: "diam" is "in diameter." And "thick" is "in thickness." The correct word should be used.

8-4. L.100: “StreusTenuPol” is"Streus TenuPol."

8-5. L.101: Is "A2" general?

8-6. L.174: "e" should be revised in the Greek font. "Sigma, S in the Greek font" is also unsuitable.

8-7. L.250: "with [60]" is "with ref. [60]."

8-8. L.325: "UltrafineGrained" is "Ultrafine Grained."

The manuscript needs to be revised for improvement. Some examples are shown in the Comments to the Authors.

Author Response

Response to review for metals-2528537, adressed to Reviewer 2.

 

We thank the reviewer for the careful reading of our manuscript and for the helpful comments.  Our responses are given below in blue-colored text.  Changes in the text are marked using yellow highlight.

 

Comment 1. It is well-understood an improvement of the mechanical properties in the Al-Mg alloys in this manuscript. However, the manuscript is further improved with the typical figures showing the relationship between the Al₃Ni and PSN phenomena from a scientific standpoint. The reviewer expects that Figure 7 is one of the keys in this manuscript. Although the authors explained the Al₃(Sc, Zr) well, more description of the Al₃Ni and related PSN needs more. The reviewer suggests that the authors describe the grain refinement process in detail. For achievement, the authors should take additional images and figures. Besides, the reviewer recommends adding the schematic illustration of the process of grain refinement and PSN.

PSN effect as a phenomenon is well discovered and explained in the handbooks for traditionally thermomechanical treated Al-based alloys. The key impact of the present study is to demonstrate that the PSN works during severe plastic deformation, particularly during multidirectional forging, and it helps to improve the microstructure homogeneity, grain refinement effect and strength of the alloys. The number of words for Metals limited, therefore, we could not add new figures and schemes, which will also require additional explanation. Meanwhile, we revised the manuscript to add new details about PSN effect and new subfigure to demonstrate the relation between fraction of coarse particles, fraction of recrystallized grains and grain size of the alloys.

Minor Comments

1. Why don't the authors explain the materials process, including the MDF process described in L.102 is also first, before the characterization technique in the Materials and Methods section? Additionally, Table 1 should be set at the beginning or bottom of the Page.

The reference for the scheme was added.

2. In Figure 1, Details of the Al₃Ni particle are explained and added, then the story would be easy to understand for the readers; the white character on the white-based image does not match to see.

Figure 1 was corrected as follows.

3. In Figure 2, Is it possible to revise the S-S curve as the horizontal axis of the cumulative strain, which is similar to Fig.1 in the following paper?

Miura and Nakamura, Philos. Mag. Lett., 63(2013), 601 (http://dx.doi.org/10.1080/09500839.2013.827800).

The recommended paper is informative and interesting and this paper and an additional one were referenced. Figure 2 was corrected as follows.

4. In Figure 5, Why don't you use the KAM maps? The reviewer expects that it is suitable to show the deformed and recrystallized grain structure.

The KAM maps and corresponding description were added to the manuscript.

5. In Figure 6, the horizontal axis of the real number is better than the log. Why did the authors use the log axis?

Figure 6 was corrected as follows.

6. In Figure 7, The reviewer guesses the intensity of superlattice spots is increasing with increasing of the ordered precipitates. Please compare the diffraction patterns of (g) to (I), and explain the intensity of the superlattice spots. Also, can the authors use the diffraction pattern taken from <110> in (h)?

An intensity of the reflexes was similar and depended on the image contrasting and particular grains in the reflected position.

We presented the SAEDS corresponded to the particular dark field images. Figure (h) is informative and demonstrates very fine recrystallized grain oriented in [110] direction observed by TEM. Similarly fine grains were observed in the alloy with 4%Ni.

There were no difference observed in the precipitates parameters between the alloys. This conclusion agreed to atom probe tomography results presented in ref.[1,2], demonstrated that Ni was not observed in the precipitates that is reasonable because of Ni could not form supersaturated solid solution in Al in the normal conditions.

1. Michi R.A. et al. Ambient- and elevated-temperature strengthening by Al3Zr-Nanoprecipitates and Al3Ni-Microfibers in a cast Al-2.9Ni-0.11Zr-0.02Si-0.005Er (at.%) alloy // Mater. Sci. Eng. A. 2019. Vol. 759. P. 78–89.
2. Suwanpreecha C. et al. Strengthening mechanisms in Al Ni Sc alloys containing Al3Ni microfibers and Al3Sc nanoprecipitates // Acta Mater. 2019. Vol. 164. P. 334–346.

 

7. Why don't the authors use the S-S curves but a table to describe Mechanical properties?

Stress-strain data were added in Figure 9.

8. There are many mistakes, like typos, in the manuscript. The reviewer recommends revising the manuscript thoroughly by the authors. Some example is suggested as follows.

8-1. L53: "p" is P? Or it seems not to be a single paragraph?

It was a typical mistake, sorry for inconsistence. The line was corrected.

8-2. L.89: "energy dispersive detector" is energy dispersive "spectroscopy." The technique should be explained, as well as the facilities.

Thank you, it was corrected.

8-3. L.99: "diam" is "in diameter." And "thick" is "in thickness." The correct word should be used.

Thank you, it was corrected.

8-4. L.100: “StreusTenuPol” is"Streus TenuPol."

Thank you, it was corrected.

8-5. L.101: Is "A2" general?

Yes, this electrolyte A2 (Struers produced) is general and information about its chemistry is available in web site struers.com.

8-6. L.174: "e" should be revised in the Greek font. "Sigma, S in the Greek font" is also unsuitable.

Corrected. We normally used the Greek characters to explain stress (σ) and strain (ε), (e) was corrected to (ε) and defined in the text.

8-7. L.250: "with [60]" is "with ref. [60]."

Corrected.

8-8. L.325: "UltrafineGrained" is "Ultrafine Grained."

Corrected.

 

Author Response File: Author Response.pdf

Reviewer 3 Report

The work studies the effects of multidirectional forging on the microstructure and mechanical properties of Al-Mg-based alloys. The topic is interesting, the methodology is clear and the results relevant. However, some clarifications are required:

Introduction

- " A positive effect of ... [8,17,22-25]": This sentence is too general.

- "Manganese [50], particles (dispersoids)": This part is not clear, something is missing or there are problems in text formatting.

Materials and methods

- Table 1: Are the data taken from the literature or measured?

- I suggest adding a scheme of the methodology adopted.

Stress-strain behaviour during MDF

- Eq. 3: What is h'?

- Strain rate equal to 0.0075: Is a unit of measurement missing?

- "For the studied alloys and deformation m was taken as 0.2": Why?

- For cumulative strain you use e, while in general you use epsilon in the manuscript: Why?

- "By way of comparison between the grain structure and its homogeneity after MDF, low magnification images after one cycle and five cycles are presented in Figure 4": The caption of Fig. 4 is "Grain structure of the (a, d) 1Ni, (b,e) 2Ni and (c,f) 4Ni alloys: (a-c) a after 3 passes and (d-f) after 15 forging passes". The caption is misleading.

Author Response

Response to review for metals-2528537, adressed to Reviewer 3.

 

We thank the reviewer for the careful reading of our manuscript and for the helpful comments.  Our responses are given below in blue-colored text.  Changes in the text are marked using yellow highlight.

 

Comments

The work studies the effects of multidirectional forging on the microstructure and mechanical properties of Al-Mg-based alloys. The topic is interesting, the methodology is clear and the results relevant. However, some clarifications are required:

Introduction

- " A positive effect of ... [8,17,22-25]": This sentence is too general.

The sentence was corrected.

- "Manganese [50], particles (dispersoids)": This part is not clear, something is missing or there are problems in text formatting.

Corrected. The sentence was not completely removed in the initial version.

Materials and methods

- Table 1: Are the data taken from the literature or measured?

The presented compositions were measured using SEM-EDS analysis.

- I suggest adding a scheme of the methodology adopted.

The current MDF scheme was previously used in our several studies. The reference for the scheme was added.

Stress-strain behaviour during MDF

- Eq. 3: What is h'?

Thank you. The typo was corrected to “h” that is a sample high

- Strain rate equal to 0.0075: Is a unit of measurement missing?

Thank you. It was corrected to  s^-1

- "For the studied alloys and deformation m was taken as 0.2": Why?

The corresponding reference was added.

- For cumulative strain you use e, while in general you use epsilon in the manuscript: Why?

Corrected. We normally used the Greek characters to explain stress (σ) and strain (ε), (e) was corrected to (ε) and defined in the text.

 

- "By way of comparison between the grain structure and its homogeneity after MDF, low magnification images after one cycle and five cycles are presented in Figure 4": The caption of Fig. 4 is "Grain structure of the (a, d) 1Ni, (b,e) 2Ni and (c,f) 4Ni alloys: (a-c) a after 3 passes and (d-f) after 15 forging passes". The caption is misleading.

The text and caption were corrected.

 

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The revised manuscript is much improved. However, the following corrections are needed. After revision, I would like to recommend to accept for publication in Metals.

1. P.3 L.123 The caption of Table 1 should be set at the beginning of P.4.  

 

2. Regarding minor comment 1, the reviewer guesses that the authors investigated your works as follows.

 

1. The preparation of materials  (L.109-L.121)

2. Process investigation of multi-directional forging. (L.156-L.165)

3. Mechanical properties evaluation (L.166-L.173) and microstructure characterization (L.125-L.155).

 

It is unnatural and difficult to understand the authors’ experimental flow of the forging after the microstructural characterization, which is explained in the story in the manuscript.

If the comment above is correct, the experimental procedures should be explained in the same as the authors’ workflow in the 2. materials and methods section.

Author Response

Response to review (Round 2) for metals-2528537, adressed to Reviewer 2.

 

We thank the reviewer for the careful reading of our manuscript and for the helpful comments. Our responses are given below in blue-colored text.  Changes in the text are marked using yellow highlight.

 

The revised manuscript is much improved. However, the following corrections are needed. After revision, I would like to recommend to accept for publication in Metals.

1. P.3 L.123 The caption of Table 1 should be set at the beginning of P.4.  

Corrected

2. Regarding minor comment 1, the reviewer guesses that the authors investigated your works as follows.

 

1. The preparation of materials  (L.109-L.121)
2. Process investigation of multi-directional forging. (L.156-L.165)
3. Mechanical properties evaluation (L.166-L.173) and microstructure characterization (L.125-L.155).

 

It is unnatural and difficult to understand the authors’ experimental flow of the forging after the microstructural characterization, which is explained in the story in the manuscript.

If the comment above is correct, the experimental procedures should be explained in the same as the authors’ workflow in the 2. materials and methods section.

Following the reviewer recommendation, we modified the “Materials and Methods” section by transferring the description of the MDF procedure in the beginning of the section. We suggest this should simplify the perception of the manuscript. The result section was not change since the consequences of presented result corresponds to the actual consequence of the material investigation.

 

Author Response File: Author Response.pdf