Continuous and Intermittent Planetary Ball Milling Effects on the Alloying of a Bismuth Antimony Telluride Powder Mixture
Round 1
Reviewer 1 Report
The paper is well written, with some possibilities of improvement in the figures:
Figure 2. Agglomerated powder (a) before and (b) after agate grinding and sieving, (c) Milling process
Figure 8. Scanning electron microscopy images: (a) SE detector, (b) BSE detector
Possibly improve the quality of SEM Images
Publish as is, after minor revision of figure 2 and 8
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
In this manuscript, the authors present a comprehensive and well-structured research conducted on the manufacturing process of a bismuth telluride thermoelectric (TE) alloying using mechanical alloying (MA) and planetary ball milling (PBM) techniques. The study demonstrates the potential for these techniques to produce TE powder materials in large quantities, more efficiently, and with less time and energy. The authors have done a commendable job in providing a clear and informative description of the methods results and implications of their work. Overall, the manuscript effectively covers the main objectives and findings of the study which could provide a strong foundation for researchers in this fields and industry applications.
Here are some suggestions and comments that I hope the authors could address:
1. Background and motivation: while the authors provide a very thorough introduction to the field of TE materials and the use of MA and PBM techniques. It could be great if they could emphasize their work in the context of the broader field. For instance, they could discuss how their findings in this study contribute to the development of more efficient TE materials or potential applications in supporting other researches.
2. The manuscript, provide a very detailed explanation of the experimental procedures including the materials used, milling conditions and analytical techniques. It would be beneficial to briefly mentioned the rationale behand choosing the specific TE alloy (Bi0.4Sb1.6Te3.0) investigated in this study.
3. In the conclusion part, the authors conclude the findings in this research and talked about potential manufacturing techniques to improve the production of TE materials. It would be advantageous to briefly discuss the limitations of the study and potential future works needed to validate the applicability of these methods to other TE materials and their potential for large scale production.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Reviewer 3 Report
The manuscript describes the mechanicall alloying of a composition modifying the milling process. This work could be an interesting to publishing but, before it, some clarifications mus be made.
As is described by de authors, after selected milling times the powder sample was taked out the vial, grinding manually and them sieved but, after this last step, all the powder was retorned to the vial or the large size powder was throw away.
When the amount of precessed powder change from 100 to 150 g, the ball to powder ratio (BPR) also changed from 8.6:1 to 5.7:1, respectively. This change in the BPR affect directly the impacts number during the milling and, indirectly the transfered energy to the powder. Therefore, in the line 149 the authors conclude that "reducing the powder mixture quantity by 50% reduces the optimum milling time for the alloying process by a factor of two" and, this statement could be true but, the efect of the BPR is more relevant to speed up the milling process. In my opinion this conclusion must be revised.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Reviewer 4 Report
The authors investigated the effects of continuous and in-steps mechanical alloying of a bismuth antimony telluride powder mixture by the mechanical planetary ball milling process as a function of milling time and powder mixture amount and obtained interesting results. The manuscript may be published after correction.
1. The abstract is overly detailed. It should be shortened, leaving only the main points.
2. Some X-ray diffraction patterns are presented in the usual format (Fig. 4), some X-ray diffraction patterns (Figs. 1, 3, 5, 6) are presented in a logarithmic scale. Representing X-ray diffraction patterns in a logarithmic scale makes it difficult to understand the structure. The use of a logarithmic scale makes it possible to show all diffraction reflections, but it significantly complicates the analysis of the process kinetics.
Lines 123-124: "According to the 24 hours x-ray plot, the characteristic tellurium peak appears to have completely faded, compared to the 12 hours plot (Fig. 1), and is now at the noise level." One could agree if the XRD pattern was not on a logarithmic scale
3. Figure 1 should be described in more detail. What does the bar chart below correspond to (only the JCPDS number is indicated). What compound does it correspond to?
4. It is desirable to add links to articles of recent years
Some terms do not seem to be generally accepted. For example,
XRD plots should be replaced by X-ray diffraction patterns
Author Response
Please see the attachment.
Author Response File: Author Response.docx
