Cryogenic Deformation Behavior and Microstructural Characteristics of 2195 Alloy

Round 1

Reviewer 1 Report

Detailed and general comments are given it the attached file

Comments for author File: Comments.pdf

Author Response

Dear reviewer:

Thank you very much for your letter and the comments concerning our manuscript entitled “Cryogenic deformation behavior and microstructural characteristics of an Al-Cu-Li alloy” (ID metals-1300208). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied the comments carefully and made corrections which we hope meet with approval. The main corrections in the paper and the responds to the reviewer’s comments are as below.

 

Responds to the reviewer’s 1 comments:

 

(1) Response to comment 1.

Response: According to the suggestion, the references on temperature effects in FCC structures have been added.

 

(2) Response to comment 2.

Response: According to the suggestion, the heat treatment processes and the initial microstructure of both states have been added.

 

(3) Response to comment 3.

Response: According to the suggestion, the discussion has been re-written.

 

(4) Response to comment 4.

Response: According to the suggestion, ref. 18, 19, 21 have been replaced.

 

(5) Response to comment 5.

Response: According to the suggestion, the name of the alloy (2195) has been added adirectly in the title.

 

(6) Response to comment 6.

Response: According to the suggestion, the “initial state” in line 24 have been removed.

 

(7) Response to comment 7.

Response: According to the suggestion, “Ideal” material in line 30 have been replaced.

 

(8) Response to comment 8.

Response: According to the suggestion, the information about studied materials in line 37-38 have been added.

 

(9) Response to comment 9.

Response: We are sorry for the ambiguous expression of line 52. According to the suggestion, the sentence was changed to “Park and Niewczas [19] studied the plastic deformation of commercial purity aluminum and AA5754 alloy at 4.2 K, 78 K, and 295 K. The two materials showed flow instabilities at 4.2 K and 295 K, while the flow instability was suppressed at 78 K, showing uniform de-formation”.

 

(10) Response to comment 10.

Response: According to the suggestion, the same information in line 66-69 have been removed.

 

(11) Response to comment 11.

Response: We are sorry for the ambiguous expression of line 93: GB/T etc, the sentence was changed to “The samples were prepared according to ISO 15579: 2000 standard”.

 

(12) Response to comment 12.

Response: According to the suggestion, the speed in line 100 have been replaced by the deformation rate.

 

(13) Response to comment 13.

Response: According to the suggestion, Fig. 2 have been enlarged.

 

(14) Response to comment 14.

Response: We are sorry for the ambiguous expression of line 119: the definition of TEM sample preparation. According to the suggestion, the sentence was changed to “Then electropolishing using a Tenupol 5 machine (Struers) with a solution of 30% nitric acid and 70% methanol at -30℃ to -20℃ and 15 to 20 V.”

 

(15) Response to comment 15.

Response: According to the suggestion, the title in line 176 have been replaced by “fracture surfaces analyses”.

 

(16) Response to comment 16.

Response: According to the suggestion, the sentence in line 198 have been rewritten.

 

(17) Response to comment 17.

Response: According to the suggestion, line 200 and 202 was changed to “the height difference between the peak and valley of the deformed sample at 77 K was significant, but the peak and valley height difference at 298 K was slight”.

 

(18) Response to comment 18.

Response: According to the suggestion, the title in line 219 have been replaced by EBSD and the initial structure have been added.

 

(19) Response to comment 19.

Response: The evidence for temperature-induced modification of plastic deformation mode is given in Fig 8 to Fig 12 and Table 1.

 

(20) Response to comment 20.

Response: According to the suggestion, the solid solution strengthing is discussed and some references are cited

 

(21) Response to comment 21.

Response: According to the suggestion, the alloy referenced in [20] has been replaced with the same composition as in this work.

 

(22) Response to comment 22.

Response: According to the suggestion, the Burger’s vector in line 273 have been revised.

 

(23) Response to comment 23.

Response: TEM observations are qualitative analysis, not quantitative analysis. The dislocation density is not counted under TEM. The processing method of all TEM samples is the same, and the thickness of the sample is close.

 

(24) Response to comment 24.

Response: According to Li-Lih Wang[1] the research results shown that there may be effective thermal activation conditions for dislocation motion in aluminum alloys at room temperature.

[1] Wang L.L. A Thermo-Viscoplastic Constitutive Equation Based on Hyperbolic-Shape Thermo-Activated Barriers[J]. J. Eng. Mater. Technol. 1984, 106(4): 331-336. https://doi.org/10.1115/1.3225726

 

(25) Response to comment 25.

Response: Under a zone axis orientation, just observe the difference of dislocations under different deformation conditions. Under the same zone axis orientation, it is helpful to eliminate the influence of other factors, and the high diffraction intensity will not affect the test results.

 

(26) Response to comment 26.

Response: According to the suggestion, “W-temper” have been replaced by “W-state”.

 

(27) Response to comment 27.

Response: According to the suggestion, the magnification of Fig. 14 and 15 have been revised.

 

(28) Response to comment 28.

Response: According to the suggestion, the information about diffraction conditions in Fig. 16 have been added.

 

(29) Response to comment 29.

Response: According to the suggestion, the item in line 377 have been canceled.

We appreciate for Reviewers’ warm work earnestly, and hope that the correction will meet with approval. Once again, thank you very much for your comments and suggestions.

Sincerely yours

Cheng Wang

Reviewer 2 Report

Very interesting work, well done. Various ways to improve the machinability of various metal alloys are currently being investigated. In this aspect, the study of cryogenic deformations is in line with the latest world trends.
The authors demonstrated a significant influence of cryogenic deformation behavior and microstructural characteristics of an Al-Cu-Li alloy.
The drawback of the work is the lack of information on the number of tested samples and the lack of statistical analyzes of the obtained results.

Author Response

Dear reviewer:

Thank you very much for your letter and the comments concerning our manuscript entitled “Cryogenic deformation behavior and microstructural characteristics of an Al-Cu-Li alloy” (ID metals-1300208). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied the comments carefully and made corrections which we hope meet with approval. The main corrections in the paper and the responds to the reviewer’s comments are as below. 

Response: According to the suggestion, the information on the number of tested samples have been added and statistical analysis was enhanced.

Reviewer 3 Report

This manuscript deals with microstructure and mechanical properties of an AlCuLi alloy, specifically the properties of the alloy at cryogenic temperatures are compared with those at room temperature. It is well written, without flaws and in good English. Therefore, it deserves publication.

Optional proposal to improve the quality of the paper: The results presented in the manuscript are obviously linked with the diffusion speed of Li atoms in the AlCu matrix. AlLi alloys are not structurally stable even at room temperature, at least from the point of view of the phase composition (fast natural ageing, even overaging). Cf. also the Portevin-Le Chatelier effect (dynamic interaction of moving solutes with moving dislocations), gradually disappearing when the temperature of deformation is decreased. The improved mechanical properties at lower temperatures can thus be linked also with more efficient static solute locking (stabilizing the microstructure and preventing the dynamic recovery).

The reviewer invites the authors to discuss their results in terms of solute diffusion and its influence on the mechanical properties at low temperatures.

Author Response

Dear reviewer:

Thank you very much for your letter and  comments concerning our manuscript entitled “Cryogenic deformation behavior and microstructural characteristics of an Al-Cu-Li alloy” (ID metals-1300208). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied the comments carefully and made corrections which we hope meet with approval. The main corrections in the paper and the responds to the reviewer’s comments are as below.

Responds to the reviewer’s comments:

Response: According to the suggestion, a discussion of solute diffusion and its influence on the mechanical properties at low temperatures have been added.

 

 

Reviewer 4 Report

• The ABSTRACT section is well-structured. The aims and objectives of the research are well defined.

• The paper is structured properly (INTRODUCTION, MATERIAL & METHODS, RESULTS & DISCUSSIONS, CONCLUSIONS, REFERENCES, etc.).

• The INTRODUCTION section provide the necessary background information.

• The METHODOLOGY is relatively well described.

• The body of paper describe the important RESULTS of the research.

• The CONCLUSION section succinctly summarize the major points of the paper.