Enhancement of Damping Capbility of MnCu Alloy by High Magnetic Field
Round 1
Reviewer 1 Report
Review report of metals-2089329
This paper titled " Enhancement of damping capability (?) of MnCu alloy by high magnetic field" was worth for publication after revision taking the following points into consideration.
(1) Figure 1: For better comparison and easy understanding for readers, the micrographs for the 0Tsample should be added as was done in Fig. 7: reprinted from ref. 6.
(2) Ni concentration determined by EDS: The four points shown in Fig. 2(a) seems to be selected as typical Cu-rich zone (right?) If so, "the average Ni content of the alloy was 5.4%" written on page 3 would confuse the readers because the Ni content of the alloy was 2 at%. It must be "the average Ni content of selected segregated regions" or some other appropriate expression should be used. Could you add the explanation why the four points in Fig. 2(a) were chosen and why such Ni enrichment was enhanced by magnetic field form the viewpoint of thermodynamics. The Ni amounts in non-rich Ni areas determined by EBSD should be presented to find the deviation.
(3) Figure 3: To demonstrate the twin structure, the diffraction patterns related to (a) and (b) should be presented with indexes. TEM microstructures of (c) and (d) are difficult to understand without further explanation; two different regions observed in (c) are fcc and fct1?; what the different d spacing means?; these d spacings are for {111} lattice spacing indicating different phases?; etc., etc.
(4) Figure 4: same with the above (1), the profile for the 0T sample should be added. Here, all the diffraction peaks for the 1T sample are weaker compared with those for the 2T and 3T samples and hence the change in texture cannot be found. The hkl intensity ratio or some suitable index must be employed for claiming the texture change with application of magnetic field.
(5) References list: numbering was shifted in the pdf version.
Comments for author File: 
Comments.pdf
Author Response
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Author Response File: Author Response.pdf
Reviewer 2 Report
Dear Authors,
The manuscript you submitted is well-organized and written in an understandable way. The MnCuNiFe alloy directionally solidified under a high magnetic field shows interesting properties. Your evaluation of the microstructure, composition distribution, and phase transformation behavior is clearly presented and show the damping capability of the alloy. The clear effect on the refinement of the dendrite microstructure by the magnetic field is also evident. Enclosed are a few comments from me on your manuscript:
A literature reference on "cold physical field" would be nice. I am not familiar with the term and an internet search did not yield a clear definition.
Fig. 1 shows the microstructure of cross... Here you should make direct reference to 1T, 2T, and 3T.
The phrase "black dendrites" and "white interdendritic distance" should be replaced by "dendrites, black shown,..." and "interdendritic distance, white...;...".
Why does the number 1 have an apostrophe?
One should mention after "2.6 times" that 3T is meant here.
The discussion is mainly about 1T; why are the results of 2T and 3T not mentioned more clearly, even if they are very similar?
The order of the references could be improved; 16 comes before 14, 17, and 19 are missing.
Respectfully
Author Response
Thank you for your comments. See the attachment for your reply.
Author Response File: Author Response.pdf
Reviewer 3 Report
The effect of static magnetic fields on the directionally solidified MnCuNiFe alloy was investigated. These Mn-Cu based alloys are known because of their excellent damping capacity. Longitudinal magnetic fields with strengths 1 T to 4 T led to refining of the dendrites, Ni enrichment, and (111) preferred orientation of the specimen. The structure refinement and the enhanced texture led to an improved damping behavior of samples directionally solidified under high magnetic field. This is seemingly due to the high mobility of twin boundary relaxation achieved by the novel microstructural features.
The paper is clearly written and needs only a few technical corrections:
(1) Please, correct on p. 2: … to 475 => … to 475 K
(2) Please, correct on p. 6: (5.9441 × 104 J/mol) => (5.9441 × 104 J/mol) (exponent!)
(3) In figure 6 a-c two scales (Tan Delta; Storage Modulus) are given for the y-axes. It is not clear to which unit the two bundles of curves are related. Please, indicate this by arrows in the plots.
(4) I cannot really understand the meaning of the following text phrase (p. 3, 8): ‘…the average Ni content of the alloy is increased by 33% by directional solidification under high magnetic field. …’. Do you mean the enrichment in the interdendritic regions? A thorough explanation is necessary!
Author Response
Thank you for your comments. See the attachment for your reply.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The manuscript has been revised taking the reviewer's comments into consideration.
