Al-5Er-Ti Master Alloy with Both Grain Refinement and Microalloying Effects
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsDear Authors, the review article is good, but I have some comments and questions.
1. The refinement can be achieved by means of a liquid metal electromagnetic mixing process in the casting mould. This is not included in the literature analysis.
2. The effect of the modifying additive refines the grain, but is negative due to the reduction in the electrical conductivity of pure aluminium. This is not included in the literature analysis.
3. Figures 1(a), 3(a), 4(d), 5(d) (e) (f) and 6 should be enlarged.
4. Conclusion 3 is obvious. When we increase the cooling rate (reducing the wall thickness of the casting), we refine the microstructure.
Author Response
- The refinement can be achieved by means of a liquid metal electromagnetic mixing process in the casting mould. This is not included in the literature analysis.
Response: We have added reference [20] for supplement the relevant literature on the effect of electromagnetic stirring on grain refinement.
- The effect of the modifying additive refines the grain, but is negative due to the reduction in the electrical conductivity of pure aluminium. This is not included in the literature analysis.
Response: We have added reference [26] and [27] to support that the modifying additive is negative to the reduction in the electrical conductivity of pure aluminium.
- Figures 1(a), 3(a), 4(d), 5(d) (e) (f) and 6 should be enlarged.
Response: These figures have been enlarged in the revised manuscript.
- Conclusion 3 is obvious. When we increase the cooling rate (reducing the wall thickness of the casting), we refine the microstructure.
Response:We have cancel this conclusion.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe manuscript is focused on the influence of Ti in the master alloys on the grain refinement of the cast Al containing Er and Ti as grain refiners. Although it includes several significant results, the present form does not allow the reader to have a simple orientation in the experiment and the interpretation. The way how the material was prepared is not clearly explained. Cooling rates are supposed to play an important role. However, no estimation was performed. Different phases are mentioned but not indicated in the figures. The role of age hardening is not related to the topic of the manuscript. Discussion is shallow or missing. Results are listed without any more profound analysis or explanation of their relevance. The manuscript contains numerous formal, statistical, and scientific faults. A representative list is mentioned in the following text.
16 use rounded values supported by relevant statistics
74 explain the relation between the cooling rate and the thickness of the ingot
75 explain the abbreviation ICP
85,86,88 explain the difference between Bourbon and Boyle solution
98 specify annealing periods correctly
103 Quanta 650 was not produced in the US
125 Figure 1: indicate (by arrows, circles, etc.) Al3Er and Ti2Al20Er particles
136 use rounded and statistically relevant values for a refining effect
139 Figure 2 d): provide information about the experimental scatter
151 Fig. 3: identify different phases in b and c
156 Figure 4d: provide experimental scatter also further in the text where the size of grains or particles is mentioned
184-190 provide experimental scatters and use statistically relevant values for the particle size
190 the sentence is not correct
213 Figure 8 is not related to the text. Figure 6 should be used instead.
215-216 The sentence is not correct. It is not clear which figure the grain size refers to.
222 E2E: provide the reference or explain the model in more detail
228-232 The text is probably not a part of the figure caption
250 Par. 3.5. The casting conditions of the material used in Par. 3.5. are not specified. Which type of particles was dissolved during the solution treatment
Comments on the Quality of English Language
English should be improved throughout the whole manuscript. Some parts of the manuscript could be understood only with a high effort.
Author Response
16 use rounded values supported by relevant statistics
Response: We have rounded off the measured phase sizes to one decimal place.
74 explain the relation between the cooling rate and the thickness of the ingot
Response: The solidification process was simulated by AnyCasting software, and the corresponding cooling rates were 0.8℃/s,1.9℃/s, 33.2℃/s for 5mm,12mm,22mm thick ingots, respectively.
75 explain the abbreviation ICP
Response:Inductively Coupled Plasm Spectroscopy
85,86,88 explain the difference between Bourbon and Boyle solution
Response: Both solution are used for etching the samples for metallographic observation. We mainly use Boyle solution in this investigation, So the text about the Bourbon solution was canceled in the revised manuscript.
98 specify annealing periods correctly
Response:In order to verify the microalloying effect of the refined samples, the samples were aged directly at 350℃, or solutionized at 620℃ for 20h and then aged at 350℃.
103 Quanta 650 was not produced in the US
Response:We have caneled “in the US”. “The microstructure observation of the master alloy was carried out on the Quanta650 scanning electron microscope produced by FEI Company.”
125 Figure 1: indicate (by arrows, circles, etc.) Al3Er and Ti2Al20Er particles
Response: Al3Er and Ti2Al20Er particles were indicate by arrows in the revised manuscript.
136 use rounded and statistically relevant values for a refining effect
Response: The refined grain size is the statistical avarage value.
139 Figure 2 d): provide information about the experimental scatter
Response: We have add the experimental scatter data in the revised figure.
151 Fig. 3: identify different phases in b and c
Response: The different phases were indicate by arrows in the revised manuscript.
156 Figure 4d: provide experimental scatter also further in the text where the size of grains or particles is mentioned
Response: We have add the experimental scatter data in the revised figure.
184-190 provide experimental scatters and use statistically relevant values for the particle size
Response: We have add the experimental scatter data in the revised figure.
190 the sentence is not correct
Response: We have correct it.
213 Figure 8 is not related to the text. Figure 6 should be used instead.
Response: We have change it to “Figure 6”.
215-216 The sentence is not correct. It is not clear which figure the grain size refers to.
Response:”The grain size of the sample cast at 805℃ is larger than that of the sample cast at 705℃. After high temperature treatment at 955℃, the grain size of the sample cast at 705℃ is significantly larger than that of the samples without high temperature treatment as shown in Figure 4c.” We have revised these sentences. The grain size of the samples after high temperature treatment are larger than that of the sample as shown in figure 4.
222 E2E: provide the reference or explain the model in more detail
Response:”To evaluate the nucleation ability of Ti2Al20Er, the crystal matching between Ti2Al20Er and α-Al was studied using the E2E model[10].” Reference[10] describe crystallographic study of grain refinement in aluminum alloys using the edge-to-edge matching model.
228-232 The text is probably not a part of the figure caption
Response: These text was canceled from the figure caption in the revised manuscript.
250 Par. 3.5. The casting conditions of the material used in Par. 3.5. are not specified. Which type of particles was dissolved during the solution treatment
Response: The casting condition of the materials used in section 3.5 is “Melt of 750g high-purity aluminum at 955℃, and then decrease the temperature to 705℃ for 3min to keep the temperature of aluminum melt stable. The master alloy (2wt%) is added in the aluminum melt and stirred for 20s. The melts was hold at 705℃for 60min. then casting into a cylindrical steel mold with a thickness of 5mm. The cylindrical refined sample with a size of φ60×20mm3was obtained.” During the solution treatment, the Al3Er phase dissolved and precipitation hardening during ageing treatment.
Reviewer 3 Report
Comments and Suggestions for AuthorsIn the form presented, I cannot recommend the paper for publication. Firstly, the style of presentation, like the English, is rough. There were several locations where I was unable to follow the intent of the writing. In addition, there are many typos.
- What amount of ligature was introduced into the Al melt?
- You control the thickness of the ingot. Explain. The Method Section reports a constant ingot diameter of 60 mm.
- Provide Figure 1 b and c at the same magnification.
- Figure 2 d is difficult to read.
- Round off the measured phase sizes to one decimal place.
- What is the solubility of erbium and titanium in aluminum? Which phase is precipitated during aging?
- Line 33. Is a dot needed here?
- Line 82. Check the phrase.
- Line 85. Is a dot needed here?
Lines 114-117 and Lines 118-121. Repeat text ‘Scanning electron microscope microstructure of Al-Er(-Ti) master alloys are shown in Figure 1b and Figure 1c. The primary phase Al3Er of the Al-5Er master alloy is distributed in long strips along the grain boundaries, forming a lamellar structure (Figure 1b). The Al3Er of Al-5Er-0.5Ti master alloy is still lamellar (Figure 1c)’
- Line 141. ‘(c) 0%’ should be replaced with ‘(c) without master alloy’
- Line 177. Is a dot needed here?
- Line 213. Is Figure 8 correct here?
- Line 229. Is a dot needed here?
- Line 260. ‘Conclusions’. Is this a typo?
Comments on the Quality of English LanguageEnglish is rough. There were several locations where I was unable to follow the intent of the writing. In addition, there are many typos.
Author Response
In the form presented, I cannot recommend the paper for publication. Firstly, the style of presentation, like the English, is rough. There were several locations where I was unable to follow the intent of the writing. In addition, there are many typos.
Response:We have improve the manuscript thoroughly.
- What amount of ligature was introduced into the Al melt?
Response: 2wt% of AlErTi master alloy was introduced into the Al melts to control the composition of Er to 0.1wt% and Ti to 0.03wt% for the Al-5Er-1.5Ti. For the addition of Al-5Er-0.5Ti, the composition of Er is 0.1wt% and Ti is 0.01wt%.
- You control the thickness of the ingot. Explain. The Method Section reports a constant ingot diameter of 60 mm.
Response: Most of the master alloy has a size of 200×100×5mm3. In order to study the effect of cooling rate on the primary phase size and grain refinement ability, Al-5Er-1.5Ti master alloy ingots with different thickness of 5mm,12mm,22mm were prepared to regulate the cooling rate. The constant ingot diameter of 60 mm is for the grain refinement sample.
- Provide Figure 1 b and c at the same magnification.
Response:Sorry! We can not provide figure with the same magnification due to the due to time constraints on modification.
- Figure 2 d is difficult to read.
Response: We have revised the caption and corresponding text. Figure 2d is the average grain size of the refine samples as a function of the holding time. As shown in figure 2d, with the addition of Al-5Er master alloy, the grain size decreases gradually with the extension of holding time, and the minimum size is 3300μm at 240min. With the addition of Al-5Er-0.5Ti master alloy, the grain size also decrease with the extension of holdingtime as shown in Figure 2d, and the minimum grain size is 720μm after holding for 240min. The refining effect is improved by 79.4% comparing to the Al-5Er alloy.
- Round off the measured phase sizes to one decimal place.
Response: We have rounded off the measured phase sizes to one decimal place.
- What is the solubility of erbium and titanium in aluminum? Which phase is precipitated during aging?
Response:The solubility of erbium in aluminium is about 0.25wt%(0.04at%). The solubility of Ti is about 1.3wt%. Al3Er is precipitated during aging for hardening.
- Line 33. Is a dot needed here?
Response:We have correct it.
- Line 82. Check the phrase.
Response:We have correct it.
- Line 85. Is a dot needed here?
Response:We have correct it.
Lines 114-117 and Lines 118-121. Repeat text ‘Scanning electron microscope microstructure of Al-Er(-Ti) master alloys are shown in Figure 1b and Figure 1c. The primary phase Al3Er of the Al-5Er master alloy is distributed in long strips along the grain boundaries, forming a lamellar structure (Figure 1b). The Al3Er of Al-5Er-0.5Ti master alloy is still lamellar (Figure 1c)’
Response: The repeat text were canceled in the revised version.
- Line 141. ‘(c) 0%’ should be replaced with ‘(c) without master alloy’
Response:We have correct it.
- Line 177. Is a dot needed here?
Response:We have correct it.
- Line 213. Is Figure 8 correct here?
Response:We have correct it as”figure 6”.
- Line 229. Is a dot needed here?
Response:We have correct it.
- Line 260. ‘Conclusions’. Is this a typo?
Response:We have correct it.
Reviewer 4 Report
Comments and Suggestions for AuthorsDear Authors,
your paper is well written and clear. The idea to refine the grain size by means of Er and Ti addition is interesting and your results are very promising. Just a general comment: could the authors give some refeernce about the phase identification? In fact i.e. in Fig.1, the authors state that: “The primary phase Al3Er of the Al-5Er master alloy is distributed in long strips along the grain boundaries, forming a lamellar structure (Figure 1b). The Al3Er 116 of Al-5Er-0.5Ti master alloy is still lamellar (Figure 1c)”.
The image quality should be improved, because it is not possible see the phase that are discussed. MOreover, please, add arrows and the analysis point for the phase identification
Line 75: Please, describe the complete technique denomination before using acronyms (ICP).
Author Response
your paper is well written and clear. The idea to refine the grain size by means of Er and Ti addition is interesting and your results are very promising. Just a general comment: could the authors give some refeernce about the phase identification? In fact i.e. in Fig.1, the authors state that: “The primary phase Al3Er of the Al-5Er master alloy is distributed in long strips along the grain boundaries, forming a lamellar structure (Figure 1b). The Al3Er 116 of Al-5Er-0.5Ti master alloy is still lamellar (Figure 1c)”.
Response: We have added reference[28]. The corresponding paragraph also improved.
The image quality should be improved, because it is not possible see the phase that are discussed. Moreover, please, add arrows and the analysis point for the phase identification
Response:We have indicated different phased by red arrows in the revised version.
Line 75: Please, describe the complete technique denomination before using acronyms (ICP).
Response:Inductively Coupled Plasm Spectroscopy. We have added this in the revised manuscript.
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe authors have made corrections to their work. I have no further comments on this article. I recommend it for publication.
Author Response
Comment:The authors have made corrections to their work. I have no further comments on this article. I recommend it for publication.
Response:Thank you for your comments to improve the quality of our manuscript. We have adopted your suggestions and carefully revised the content of the manuscript. The revisions are marked in red in the revised manuscript.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors accepted all recommendations. I have a small note concerning the Boyle solution (l. 111). I have never heard about this name in this context and I was not able to find any reference to it. Provide a relevant reference.
Comments on the Quality of English LanguageEnglish should be significantly improved in the whole manuscript
Author Response
Comments 1: The authors accepted all recommendations. I have a small note concerning the Boyle solution (l. 111). I have never heard about this name in this context and I was not able to find any reference to it. Provide a relevant reference.
Response 1: Thank you for pointing this out.Therefore, we have demonstrated the existence of Boyle solution (120ml HCl + 60ml HNO3 + 10ml HF + 10ml H2O) by uploading the literature "Study on microstructure and refining effect of deformed Al-4.5Er-1Zr-1.5Ti master alloy".
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe manuscript was improved after revision.
Author Response
Comment1 : The manuscript was improved after revision.
Response1 : Thank you for your comments to improve the quality of our manuscript. We have adopted your suggestions and carefully revised the content of the manuscript. The revisions are marked in red in the revised manuscript.
Author Response File: Author Response.pdf
