Effect of Pressure on Densification and Microstructure of W-Cr-Y-Zr Alloy during SPS Consolidated at 1000 °C
, Andrey Litnovsky 2, Jan Willem Coenen 2,5, Christian Linsmeier 2 and Yucheng Wu 1,4Round 1
Reviewer 1 Report
This paper studies the effect of pressure during spark plasma sintering on the densification and evolution of the microstructure of a self-passivated W-Cr-Y-Zr alloy.
The paper is written at a sufficient scientific and theoretical level, but to improve it I added some comments:
1. In the introduction it would be better to add some more papers describing other authors who have done research on SPTAs alloys. There is not enough information what properties these alloys should have.
2. It is not explained exactly how the sintering temperature of 1000 °C was chosen.
3. On page 3, lines 125-126, the authors refer to the authors' previous work, but do not mark the reference.
4. Page 8, line 285, the authors should edit the figure number (instead of Figure 5, it should be Figure 6).
5. In the references (line 372) the authors should edit the reference [26].
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
This work deals with the densification kinetics and microstructure of W-Cr-Y-Zr alloys. The powder alloy was obtained by ball milling. The alloys were sintered at different applied pressures. Overall, this is a useful and interesting study. However, I have several concerns regarding the presentation and interpretation of the results.
1. The Authors published a paper in 2021 on the same topic. It is referenced [17]. I think that the results of the present study should be discussed taking into account those of [17] and in comparison with those of [17]. It is perfectly all right to report the microstructure and phase composition of the alloys sintered by SPS at different temperatures, however, it is necessary to emphasize and explain the observed differences in the effect of pressure on the composition of the W(Cr) solid solution in the two studied cases (Fig. 3 in the present paper, Fig. 2 in [17]).
2. I suggest that the Authors revise the title of the present paper to clearly show what is new in the present work (otherwise, the title is very similar to that of [17]).
3. Please provide SEM images of the polished cross-sections of the sintered alloys in the present work. Also, please include the XRD pattern of the powder alloy.
4. It would be convenient for the reader to have the phase diagram of the W-Cr system included and the processes occurring in the alloys shown on it (maybe with points and arrows to show the composition changes of the phases).
5. Why do the Authors resort to explaining the behavior of the material by viscous flow? During SPS under high applied pressures at 1000 C, is it likely to have liquid-like phases in the materials during SPS?
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
This manuscript discusses the effect of pressure on the densification process and microstructure of a sintered W-Cr-Y-Zr alloy powder. This article appears to be of good quality although I have a few comments.
1. Please give references for the equations that are you used in the manuscript.
2. In Equation (7), it should be e-Q/RT, not eQ/RT
3. What are the R2 values of the fitted lines in Figure 5?
4. Please mention what the yellow arrows and dashed lines are in the caption of Figure 6.
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The necessary revison has been made.
