Solid Fraction Determination at the Rigidity Point by Advanced Thermal Analysis

Round 1

Reviewer 1 Report

This manuscript reports an effort of applying the high rank derivatives to the solidification curve and the solid fraction curves to calculate the Solid Fraction at the rigidity point (FRP), which allows the determination of the solidification parameters.

The topic is interesting, but the manuscript is not well prepared, there are major issues need to be addressed.

1. The introduction needs to be better organized.
2. There are too many paragraphs, such as there three paragraphs from line 71-80.
3. Not sure line 87 is a starting of a new paragraph or not.
4. In the first three paragraphs of the Introduction, there is not a single reference cite, which is not convincing.

 

2. I hope to see more discussions about how this field would benefit from the results obtained in this research or the methods developed, such as the insight into reducing the casting defects, etc.

 

3. The manuscript is a bit hard to read, too many long sentences. One example is, from line 209-213, there is only one sentence comprising the entire paragraph, plus, some parts of the sentence are already very hard to read, such as line 209 “an increase in the percentage of alloying elements increases a decrease in the FRP value,”.

 

4. The format of figures need to be improved, especially from Fig. 1 to 5. Such as the different colors of the x and y axes in Fig. 2, missing of the top frame line of Fig. 3 and 4.

 

5. In between Fig. 12 and 13, there is another figure without caption.

 

6. There are quite some typos need to be corrected, to name a few:
7. There are a few “mayor and minor” I believe should be “major and minor”, such as in line 14 and 18.
8. The notation of alloys are not consistent, such as the 10 and 7 in “AlSi10Mg” and “AlSi7Mg” are not subscripts, in line 19, 30, 31, etc.
9. “Student” in line 196 – the caption of the Table 2, I believe is supposed to be “statistical”.

 

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

1. Page 1, lines 33-37: The solid fraction at rigidity point is not needed for casting simulation software. For example, in ProCast software, the only critical solid fraction at which the melt flow stopped was needed for properly misrun formation prediction in castpart. Maybe the authors can provide an example of FRP usage in simulation software?
2. Page 2, lines 81-82: Why the single thermocouple method is less expansive. Is it because of thermocouple cost? 
3. Page 3, line 102: please check the reference [23]. At now, it is [2323].
4. Page 3, line 123: Authors said about 24 experimental alloys. But table 1 provides the composition of 25 alloys. Please check.
5. Page 3, line 131: Authors said that molten aluminum was poured. Maybe using the term "alloy" is better here.
6. Page 4, lines 156-157: Authors need to explain what is shown in figure 1 and how FRP was calculated.
7. Figure 1: Authors must explain how with increasing the temperature, the fraction solid was increased. 
8. Page 5, line 165: Please provide the reference for literature data corroborating obtained experimental results. 
9. Figure 2: As I understand correctly in Figure 2, the FRP values for 25 alloys with close but different composition is provided. How can be found the regression line and where this line in the graph. No alloy composition axis is available in the figure. If the experiment was repeated 3 times, why error bars were not provided in figure 2?
10. Page 6, equation (1): The error is here. How to calculate 09-2.67...? Also, what meaning of the point between the number and element (2.67.Si, for example)?
11.  Figure 5: Please check the Sr content axis.
12. Page 7, lines 214-217: The content of impurities is low, and due to the high error of its content, determining the conclusion about reduction of FRP is ambiguous.
13. Page 7, line 220: What "larger and larger" means?
14. Page 7, lines 218-222: Please explain the mechanism of FRP influence on intermetallic particles size and shrinkage porosity? 
15. Page 7: The alloy 12 has the Si content close to binary Al-Si eutectic point. Because of that, it must have a shorter freezing range than, for example, alloy 7. It is known that a short freezing range corresponds to deep shrinkage cavity formation and no porosity. At the same time, the long freezing range corresponds to a low shrinkage cavity and high porosity. So why, in this case, does this do not work?
16. Figure 6: The large intermetallic phases are on the left, and shrinkage porosity is on the right. Please correct.
17. Page 8, lines 228-230: The suggestion about the Mg2Si preferred precipitation is wrong for the selected alloy compositions. It can present in alloys structure, but most Si is in pure form ((Si) phase).
18. Page 8, lines 238-241: What do "solidification temperature" and "solidification point" terms mean?
19. Page 8, line 242: What means "fluidity of solid particles"?
20. Page 8, lines 243-246: It is no relationship between beta Al5FeSi and Q-Al5Mg8Cu2Si phases. So why do authors think that one of them transforms into another? Would you please explain that thesis or provide the references? 
21. Page 8: I don't find any information about alloys' fluidity. Why do authors discuss fluidity and don't determine it experimentally?
22. Figure 8: How identified all these phases? There is no information about methods and equipment for microstructure observation and analysis of the composition of phases.
23. Page 9, lines 258-259: What means "more eutectic alloy behavior," and how can this behavior be seen in figure 9?
24. Figure 13: This figure is provided twice in the text. Please correct. 
25. Page 12, lines 327-331: What positive or negative here is referenced? Maybe better to use higher or lower.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The reviewer comments are adressed well.