Precipitate Behavior, Mechanical Properties and Corrosion Behavior of an Al-Zn-Mg-Cu Alloy during Non-Isothermal Creep Aging with Axial Tension Stress
Round 1
Reviewer 1 Report
This work investigates the precipitate behavior, mechanical properties and corrosion behavior of an Al-Zn-Mg-Cu alloy during non-isothermal creep aging. The document is well structured, but some parts may be unclear and lack of explanation. Below are my questions for this work:
- In NICA process, I wonder if there was a holding time at each aging temperature (120, 160, 210˚C).
- In Fig. 7, simulation results of the Al-Zn-Mg-Cu alloy during the NICA process are shown. However, there is no explanation for simulation process.
- In Fig. 7, average precipitate radius and volume fractions are calculated. At every heating or cooling temperature, different type of precipitate are observed as mentioned in manuscript. What does the precipitate in Fig. 7 mean?
- In Fig. 7, the average precipitate radius reaches its maximum when the temperature reached 210˚C. However, in Fig. 6, bigger precipitates in H160 were observed. Why does the average precipitate radius reach its maximum at 210˚C in simulation?
- There is a lack of explanation based on thermodynamic analysis to discuss the effect of heating temperature and cooling temperature, etc., based on thermodynamic of Al-Zn-Mg-Cu alloy.
- What is the identity of the particles at grain boundary in Fig. 8?
- There are typo errors in manuscript. Authors should proof-read carefully. For example, “480˚C 01h” and no description of “HTPP” in Fig. 1, “Average precipitate radium%” in Fig. 7a, and so on. Also, there are so many spacing error in manuscript.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
The authors present an interesting work dealing with the precipitation behaviour, mechanical properties and corrosion performance of an aluminium alloy subjected to non-isothermal creep aging. It has merit, but requires improvement before being published. Major concerns:
- English is poor, and there are many typos. Please, have a (detailed) look into it.
- There are a number of acronyms that require explanation (GP, SSS, HTPP, etc), and further explanation about the different phases would be welcome.
- The experimental programme is confusing. It is absolutely necessary to identify the different material conditions, with an explicit explanation on each case of the complete thermal (mechanical) treatment (e.g., C160 specimen corresponds to a treatment consisting in ....; C120..., and so on).
- Likewise, it looks that there are several specimens for each test type and material conditions. The scatter in the results is not mentioned. Are the values in the text average values? Please, specify and explain in detail.
- Review line 109.
- Also, in general, try to explain better the novelty of the work.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
There are some weaknesses through the manuscript which need improvement. My comments and suggestions I described below, in the order of their occurence in the manuscript.
1) The abbreviations should be defined first time when are used in the manuscript. E.g. GP is not explained in the Abstract, and in the Introduction too (line 43). It is not explained in the manuscript, that GP means Guinier-Preston zone. Please add information in the manuscript about the meaning of all abbreviations and symbols used in the lines 42-43. Please write in the text the abbreviation NICA in the line 90 instead of line 103. Please explain in the text the meaning of the HTTP abbreviation in Figure 1 (line 111).
2) Line 54: Please add information in the manuscript about non-isothermal aging method (NIA). What does this method involve?
3) Line 69: Please add information in the manuscript about creep age forming technology (CAF). What does this technology involve?
4) Line 113, Figure 1: Seconds in the title of the X axis are not needed, because heating and cooling processes are described in hours.
5) Lines 211-222: Figures 6d and 6e are not mentioned in the text.
6) Line 237: Instead of "in Fig.1 and Fig.2", there should be "in Fig.2 and Fig.3"
7) Line 252: Please add the reference to the mentioned Wagner and Kapmann investigation.
8) Line 263: Instead of "in Fig.6a and Fig.7a-7b", there should be "in Fig.5a and Fig.6a-6b"
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The document is well revised, and provides sufficient discussion after revision.
However, Fig. 7a (error:"Average precipitate radium%”->"Average precipitate radium/nm”) in revised manuscript is not chaged as shown in response letter. Authors should check it.
Author Response
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Author Response File: Author Response.pdf
Reviewer 2 Report
The work has been improved. Please, revise the text and correct some tipos and some references format.
Author Response
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Author Response File: Author Response.pdf
